To do list:s3.amazonaws.com/.../Chem_1_lab_manual_v4.docx · Web viewIdentify one apparatus used in the lab to accurately measure mass. What units does this apparatus use? What is

Medgar Evers College Preparatory School1186 Carroll Street

Brooklyn, New York 1125

Dr. Michael Wiltshire Genice Reid Principal Assistant Principal, Supervision

Chemistry ILaboratory Manual

Table of Contents

Lab 1 – Laboratory Equipment........................................................................................................3Lab 2 – Measurement......................................................................................................................5Lab 3 – Density................................................................................................................................9Lab 4 – Physical and Chemical Changes.......................................................................................11Lab 5 – Separation of Mixtures Using Filtration and Distillation.................................................15Lab 6 – The Atomic Mass of Pennium..........................................................................................17Lab 7 – Flame Test........................................................................................................................19Lab 8 – Ionization Energies of Elements on the Periodic Table: Periods.....................................21Lab 9 – Ionization Energies of Elements on the Periodic Table: Groups.....................................23Lab 10 – Periodic Properties Part A – Density..............................................................................25Lab 11 – Formulas of Ionic Compounds.......................................................................................27Lab 12 – Formulas of Covalent Compounds.................................................................................33Lab 13 – Solubility and Bond Type...............................................................................................39Lab 14 – Heating Curve.................................................................................................................41Lab 15 – A Hot Peanut..................................................................................................................43Lab 16 – Boyle’s Law....................................................................................................................45

v. 3.0

Name: _____________________ Date: _________Teacher: ____________________ Period: ________ OT / L

Lab 1 – Laboratory Equipment

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Define apparatus.3. Get the lab safety contract signed by yourself and your parent.4. Complete the lab safety quiz.5. Identify 5 apparatus that you have used in a previous science laboratory class.

i. State the name of each apparatus.ii. Describe the purpose of each apparatus.

6. Choose one apparatus from the previous question that you think might also be useful in a chemistry laboratory. Explain why you think that apparatus might be useful in chemistry.

Introduction:As in all sciences, chemists use many different apparatus to perform their lab experiments. This lab will familiarize you with some of these tools that we will be using throughout the course of the year.

Problem: For what purpose are various pieces of laboratory equipment used?

Materials:Lab manual, sheet with diagrams of laboratory materials, chemistry equipment catalogues.

Procedure: 1. On a separate sheet of paper, name and state the purpose of each piece of laboratory

equipment labeled 1 – 36. Base your answers on your knowledge of chemistry and your use of the textbook and catalogs provided to you.

2. Choose five pieces of laboratory equipment and indicate the cost of each item. (Use the catalogues provided.)

2

Discussion: (Answer on a separate sheet of paper)1. Which set of laboratory equipment

would most likely be used with a crucible?

2. The diagram below shows a laboratory setup that can be used in a titration.

Which pieces of equipment are indicated by arrows A and B, respectively?

3. Which diagram represents an Erlenmeyer flask?

4. Which Diagram represents a graduated cylinder?

5. A plan is being developed for an experiment to test the effect of concentrated strong acids on a metal surface protected by various coatings. Some safety precautions would be the wearing of chemical safety goggles, an apron, and gloves. State one additional safety precaution that should be included in the plan.

Conclusion: Answer the problem using complete sentences.

3


Lab 2 – Measurement

Pre-lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. For each of the following instruments, identify the quantity measured and the units in which

it is measured:a. Rulerb. Triple-beam balancec. Graduated cylinder

d. Beakere. Buretf. Thermometer

3. Based on your procedure, create a Data Table for each station 1-7 providing spaces for all of the data you’re going to collect and calculate. Note that some procedure steps require the collection of more than one piece of data. Use the sample table below as a guideline.

Sample: Station 4 Data TableItem Line Rectangular

Solid

Length

Width

Height

___________ cm _____________ cm

_____________ cm

_____________ cm

Volume _____________ cm3

Problem: How do we measure length, volume, temperature, and the mass of solids and liquids?

Measuring Length

The basic SI unit of length is the meter (m). On our ruler we can see that each centimeter (cm) is divided into 10 smaller units called millimeters (mm). Hence, 1 cm = 10 mm.

Measuring Volume

The measure for volume is a derived unit based on the fundamental SI unit of length cubed, m3. The cubic meter, m3, is the volume of a cube that is 1 m on each edge. The cm 3

(sometimes written cc), is also used. Another common measure of volume is the liter (L), a volume roughly the size of a quart. There are 1000 mL in a liter, and each milliliter is the same volume as a cubic centimeter (cm3). Thus, milliliter and cubic centimeter are commonly used interchangeably in expressing volume.

4

Measuring Mass

The basic SI unit of mass is the kilogram (kg). The unit of mass most frequently used in chemistry is the gram (g), which is 1/1000 of a kilogram. The mass of an object is determined by balancing it against a set of known masses using a device known as a balance.

Introduction:Last week we learned about some of the instruments we will be using during the year in

lab. This week, we will begin to practice some of the measurements we will be making. Rulers, triple-beam balances, graduated cylinders, beakers, burets and thermometers are all important tools for making measurements in the lab.

Procedure:Station 1: Materials: large graduated cylinder, tap water, solid object1. Fill a large graduated cylinder up to 50 mL. Write down the volume of the water. Record

your answer to the nearest 1/10 of a milliliter.2. Put the solid object into the water, making sure it is completely under water. Record the new

volume of the water with the cube in it.3. Calculate the volume of the solid object.4. Dump out the water and remove the rectangular object from the graduated cylinder.

Station 2: Materials: graduated cylinder, tap water, buret, Beaker5. Measure out 6.2 mL of water using a graduated cylinder. Sketch the cylinder to show your

measurement, using the example shown below. Pour the water down the drain when you are finished sketching the cylinder.

Example:

6. Record the initial volume of the buret when you reach station 2.7. Use the buret to transfer 10.0 mL of water to a beaker. Record the final volume of the buret.

Record your answers to the nearest 1/10 of a milliliter.

Station 3: Materials: thermometer, beaker with water.Note: For Station 3, be sure to record the time when each measurement was taken. Also be sure to rinse and dry off the thermometer between each measurement.8. Record the temperature of the air. Be sure to use appropriate units. Record your answer to

the nearest 0.5 degree. Record the time when your measurement was taken.9. Record the temperature of the water in the beaker.

5

Station 4: Materials: ruler, rectangular solid10. Measure the length of the following line:

Record your answer to the nearest millimeter.11. Measure the length, width and height of the rectangular solid.12. Calculate the volume of the rectangular solid by multiplying L x W x H.

Station 5: Materials: triple-beam balance, rectangular solid, kidney beans13. Measure the mass of the rectangular solid using the triple-beam balance. Record your

answer to the nearest 1/10 of a gram.14. Measure the mass of the kidney beans without the cup.15. Count the number of kidney beans.16. Calculate the average mass of the kidney beans.

Station 6: Materials: filter paper, salt17. Measure the mass of the filter paper. Record your answer to the nearest 1/10 of a gram.18. Weigh out 5 g of salt. Write down the combined mass of the salt and filter paper.19. Place the salt and filter paper in the garbage can.

Station 7: Materials: cup, lima beans, beaker, tap water, triple-beam balance20. Measure the mass of an empty cup. Record your answer to the nearest 1/10 of a gram.21. Place the lima beans in the cup and measure the mass of the beans.22. Calculate the mass of the beans.23. Measure the mass of an empty beaker.24. Pour approximately 50 mL of tap water into the beaker. Measure the mass of the beaker with

the water in it. Calculate the mass of the water.

Station 8: Materials: Metric Conversion Study Sheet25. Use the Metric Conversion Study Sheet to answer Discussion Question #1.

Station 9: Materials: Reference Table26. Use the Percent Error equation in Table T in the Reference Table to answer Discussion

Question #4.27. Continue working on the remaining discussion questions with any extra time.

Discussion: (Answer on a separate sheet of paper)1. Convert the following:

a. 2,000 mL = ________ Lb. 3.36 L = _________mLc. 65 cm = _________mmd. 3.2 mm = ________cme. 43 kg = __________gf. 654 g = __________kg

2. Why is it better to use the graduated cylinder rather than the beaker to measure liquid volumes?

6

3. In this lab you used two different graduated cylinders, a 10 mL graduated cylinder and a 200 mL graduated cylinder. Which graduated cylinder would you use to measure each of the following volumes? For each of your answers, explain why:

a. 8.2 mLb. 62 mL

4. A student measures the density of zinc to be 7.56 grams per milliliter. If the accepted density is 7.14 grams per milliliter, what is the student’s percent error?• Show a correct numerical setup.• Record your answer.

5. The volume of an acid required to neutralize exactly 15.00 milliliters (mL) of a base could be measured most precisely if it were added to the base solution from which of the following:

a. 1000 mL graduated cylinderb. 125 mL Erlenmeyer flaskc. 50. mL buretd. 50. mL beaker

Explain your answer.6. What is the maximum weight that can be measured on a triple-beam balance? Explain.7. The diagram below represents a section of a buret containing acid used in an acid-base

titration.

What is the total volume of acid that was used?


7


Lab 3 – Density

Pre-Lab Questions: Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Identify one apparatus used in the lab to accurately measure mass. What units does this

apparatus use? What is one other metric unit of mass?3. Identify one apparatus used in the lab to accurately measure volume. What units does this

apparatus use? What is one other metric unit of volume?4. Define density.5. a. What is the formula for density? b. What are the units for density?6. Based on your procedure, create a Data Table for each of the 3 sections providing spaces for

all of the data you’re going to collect and calculate. Note that some procedure steps require the collection of more than one piece of data. Include spaces to show the work for any calculations you will do.

Problem: How can we determine the density of a regular solid, an irregular solid, and a liquid?

Introduction: Density, a physical property of matter, is defined as mass per unit volume of a substance.

Density does not depend on the amount of a substance. This allows us to compare items that are of different sizes. For example, a large wooden block would be heavier than a small piece of gold. However, the gold is denser than the wood, because it contains more mass for its size.

Density can also be used to identify a substance. Each pure substance has its own unique density. Therefore, if we calculate the density an unknown metal and compare it to a table of accepted values, we may be able to identify the metal. In this experiment, you will find the density of a wooden block, an irregularly shaped piece of metal, and an unknown liquid solution.

Procedure:Part I: Metal Solid1. Using a balance, weigh the metal cylinder.2. Fill a large graduated cylinder about half full with tap water. Read the exact volume of water

to the nearest 1/10 of a milliliter.3. Place the metal into the graduated cylinder. Read and record the combined volume of the

water and the metal to the nearest 1/10 of a milliliter.4. Using your data, determine the volume of the metal.5. Calculate the density of the metal. Show all work.6. Ask your teacher to identify the metal for you. Look up the accepted value for the density of

your metal. Determine the percent error in your calculations. Show all work.Part II: Wooden Block7. Measure the length, width and height of the wooden block to the nearest millimeter.

Calculate the volume of the block. (Note: 1 cm3 = 1 mL)

8

8. Using a balance, weigh the block and record its mass to the nearest tenth of a gram.9. Calculate the density of the block using the density formula. Show all work.10. Ask your teacher for the accepted value of the density of the wooden block. Determine the

percent error in your calculations. Show all work.Part III: Liquid11. Measure the mass of a clean, dry graduated cylinder.12. Measure out exactly 10.0 mL of the unknown liquid solution into the graduated cylinder.13. Reweigh the graduated cylinder. Record the mass of the graduated cylinder plus the liquid.14. Calculate the mass of the liquid.15. Calculate the density of the liquid

using the density formula. Show all work.

16. Compare your density with the table on the right. Based upon the table below and any observations you made about the liquid, determine which liquid you were given.

17. Calculate the percent error in your density value. Show all work.

Discussion:1. Which is heavier, a piece of metal or a piece of wood?2. In Part I, why do you determine the mass of the solid before adding it to the water in the

graduated cylinder?3. Read the following passage and answer the question at the end:

Many years ago, a rich and powerful king was given a beautiful crown as a gift by people who wanted to win the king’s friendship. The king was pleased, but he was not sure that the crown was really made of solid gold as the gift-givers claimed. He suspected that the crown might have been made of a cheaper metal, such as lead, and then covered with just a thin layer of gold. To solve this puzzle, the king sent for the scientist Archimedes. He told Archimedes what he wanted to find out and cautioned him to perform an analysis in such a way that the crown would not be taken apart or damaged. Archimedes determined that the mass of the crown was 650 g, and the volume of the crown was 50 mL. Should the king have the gift-givers rewarded or arrested? Explain your answer and show numerical calculations to support your answer.4. When oil and water are put together, they do not mix. Which one will float to the top? Use

the information in this lab to justify your answer.5. Determine the volume of a 62-gram sample of iron at STP.6. A student used a balance and a graduated cylinder to collect the following data:Sample mass 10.23 gVolume of water 20.0 mLVolume of water and sample 21.5 mLa Calculate the density of the element. Show your work. Include the appropriate number of significant figures and proper units. [3]b If the accepted value is 6.93 grams per milliliter, calculate the percent error. [1]c What error is introduced if the volume of the sample is determined first? [1]

9

Liquid Density (in g/mL)

Butane (lighter fluid) 0.599Gasoline 0.737Isopropanol (rubbing alcohol) 0.786Ammonia 0.823Vegetable oil 0.920Water 1.000Ethylene glycol (antifreeze) 1.114


10


Lab 4 – Physical and Chemical Changes

Pre-Lab Questions: Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. a) What is the difference between an element and a compound?

b) What is the difference between a compound and a mixture?3. a) What kind of change can be used to decompose a compound? Explain.

b) What kind of change defines the separation of a mixture? Explain.4. In your own words differentiate between melting and burning.5. Based on your procedure, which substance is going to be heated and which substance is

going to be burned?

Problem: What is the difference between a chemical and physical change?

Introduction:The changes that matter undergoes can be broken down into two classes: physical

changes and chemical changes. In a physical change, one or more physical properties of a substance is altered. Examples of such physical properties include size, shape color, and physical phase. Grinding, melting, dissolving and evaporating are all physical changes. A chemical change results in the formation of one or more new substances. These new substances differ in chemical properties and composition from the original substance. The rusting of iron and the burning of paper are two examples of chemical change.

Materials: (Itemize the materials)

Procedure:Follow the instructions as written in your data table. Record your observations, classify it as a physical or chemical change, and explain your results.

Data Table:Experiment With Observations Chemical

or Physical Change?

Explain your results

Ex. Burn paper Piece of white loose-leaf paper turned black on burning.

Chemical The paper changed to a completely new substance: ash.

1. Bend a nail with 2 pliers.

11

2. a. In a test tube, add 5 drops of oil to 5 mL of water. b. Shake. 3. Light the candle wick.

4. Heat candle wax.

5. Tear paper.

6. Dissolve NaCl(s) in water.

7. Add a splintful of baking soda to a test tube with 5 mL of vinegar.8. Using a mortar and pestle, grind CuSO4·5H2O 9. Heating CuSO4·5H2O

10. Add a splintful of NaCl to AgNO3(aq).11. Add 1 mL HCl(aq) to a pinch of Mg(s).12. Mix iron (Fe) and sulfur (S)

13. Heat a mixture of Fe and S.14. Add a splintful of unknown crystal to 5 ml of water. Stir.

12

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.1. Given the particle diagram representing four molecules of a substance:

Which particle diagram best represents this same substance after a physical change has taken place?

2. An example of a physical property of an element is the element’s ability to(1) react with an acid(2) react with oxygen(3) form a compound with chlorine(4) form an aqueous solution3. Which statement describes a chemical property of oxygen?(1) Oxygen has a melting point of 55 K.(2) Oxygen can combine with a metal to produce a compound.(3) Oxygen gas is slightly soluble in water.(4) Oxygen gas can be compressed.4. Which substance can be decomposed by a chemical change?(1) calcium (3) copper(2) potassium (4) ammonia5. Which statement describes a chemical property of iron?(1) Iron can be flattened into sheets.(2) Iron conducts electricity and heat.(3) Iron combines with oxygen to form rust.(4) Iron can be drawn into a wire.

13

6. Which process represents a chemical change?(1) melting of ice (2) corrosion of copper (3) evaporation of water(4) crystallization of sugar7. Which set of procedures and observations indicates a chemical change?(1) Ethanol is added to an empty beaker and the ethanol eventually disappears.(2) A solid is gently heated in a crucible and the solid slowly turns to liquid.(3) Large crystals are crushed with a mortar and pestle and become powder.(4) A cool, shiny metal is added to water in a beaker and rapid bubbling occurs.

Conclusion: Answer the problem in complete sentences, citing examples from your data table.

14


Lab 5 – Separation of Mixtures Using Filtration and Distillation

Pre-lab questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. What is the difference between a compound and a mixture?3. What type of process is required to decompose a compound? What type of process can be

used to separate a mixture?4. Give 2 examples each of homogeneous and heterogeneous mixtures (you may not use any of

the examples listed in the introduction).5. Are homogeneous mixtures always liquids? Explain and give examples.6. Classify the following mixtures as homogeneous or heterogeneous:

a. Gravel b. Milk c. Salt water d. Wood e. Air

Problem: How can we use filtration and distillation to separate mixtures?

Introduction: A mixture is a form of matter that has a varying composition. They can be homogenous, whereby the particles are molecular-sized and mixed evenly throughout, so the mixture is considered uniform. These homogenous mixtures are classified as solutions. An example of a solution is sugar in water. Only one phase is visible. In a heterogeneous mixture, the components are large enough to be seen with the naked eye or under a microscope. Examples of heterogeneous mixtures are mixed nuts and soil. Blood would also be an example of a heterogeneous mixture.

Filtration is a mechanical process that can be used to separate a heterogeneous mixture. When the mixture is passed through filter paper, the filtrate passes through, leaving behind any solid particles that are not fully dissolved in the solution.

Distilliation is the process of separating a mixture into its component parts by using the different boiling points of the components. When the mixture is heated, some components will boil faster than the others. By allowing one component to boil off first and then collecting it, we can separate it out from the rest of the components.

Materials: Erlenmeyer flask, funnel, filter paper, mixture A, mixture B, solution C, Distillation apparatus.

Procedure:Part I: Separation of a mixture using filtration.1. Fold a piece of filter paper in half, and then over again so it is one-quarter of its original size.2. Cut off a small corner from the fold and open the paper to form a cone. The torn corner

should be on the outside, allowing the paper to form a full cone that lies flat against the funnel.

15

3. Place the filter paper into a funnel and set the funnel in a ring attached to a ring stand.4. Place a container under the funnel to catch the liquid.5. Write down what you observe to be in mixture A.6. Pour Mixture A into the funnel. Be sure to pour slowly so that the liquid doesn’t overflow.7. Record your observations. Be sure to note what passed through the funnel and what did not.8. Discard your filter paper and rinse out your glassware.9. Repeat steps 1-8 using mixture B.Part II: Separation of a solution using distillation.10. Prepare the distillation apparatus as shown by your teacher.11. Write down what you observe to be in solution C.12. Heat solution C in the soda can.13. Record your observations about the liquid that is distilled.

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.1. By using a paper filter, which of the following can be separated?(1) two immiscible liquids(2) a solid in a liquid(3) two heterogeneous solids(4) two miscible liquids2. Recovering the salt from a mixture of salt and water could best be accomplished by(1) evaporation (3) density determination(2) filtration (4) paper chromatography3. Which physical property makes it possible to separate the components of crude oil by means of distillation? (1) melting point (3) solubility(2) conductivity (4) boiling point

4. A sample is prepared by completely dissolving 10.0 grams of NaCl in 1.0 liter of H2O. Which classification best describes this sample?(1) homogeneous compound(2) heterogeneous compound(3) homogeneous mixture(4) heterogeneous mixture5. When a mixture of water, sand, and salt is filtered, what passes through the filter paper? (1) water, only(2) water and salt, only(3) water and sand, only(4) water, sand, and salt

6. Explain how you could determine that brass is a solution.7. One of the most common uses of distillation is in the preparation of alcoholic beverages. Distillation is used to take a mixture that is 15-20% alcohol by volume and make it 40% or more alcohol by volume. Look up the boiling point of ethanol (the alcohol present in these beverages). If a mixture of alcohol and water were distilled, would the product have more or less alcohol in it? Explain your answer. 8. At equilibrium, nitrogen, hydrogen, and ammonia gases form a mixture in a sealed container. The data table below gives some characteristics of these substances.

Data TableGas Boiling Point Melting Point Solubility in Water

Nitrogen - 196 °C - 210 °C insolubleHydrogen - 252 °C - 259 °C insolubleAmmonia - 33 °C - 78 °C soluble

Describe how to separate ammonia from hydrogen and nitrogen.Conclusion: Answer the problem using complete sentences.

16


Lab 6 – The Atomic Mass of Pennium

Pre-lab questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. State 2 differences between two isotopes of an element.3. What is the difference between atomic mass and mass number?4. Based on your procedure, how do you calculate relative abundance?

Problem: How is the average atomic mass of pennium determined?

Introduction: Any sample of an element as it occurs in nature contains a mixture of isotopes. As a

result, the average mass of an element’s atoms is called the atomic mass, which is also called the average atomic mass or the atomic weight. The atomic mass of an element is listed on the periodic table in the form a decimal. The average atomic mass (atomic mass) is calculated by converting the percent abundances to decimals, multiplying them by the mass of each isotope, and then adding the results.

Materials: sample of pennium, triple beam balance

Procedure:1. Obtain a sample of pennium. Separate out the two isotopes, those from before 1982 (isotope

1), and those from after 1982 (isotope 2). [Eliminate any items from 1982]. Record the amount of each isotope.

2. Measure the mass of one particle of each isotope. Record your data in the Table below.3. Calculate the percent abundance of each isotope by dividing its number of particles by the

total number of particles and multiply it by 100. 4. Calculate the relative abundance of each isotope by dividing the percent abundance from

Step 3 by 100.5. Calculate the relative mass of each isotope by multiplying its relative abundance from Step 4

with its mass.6. Calculate the average mass of all pennium particles by adding the relative masses. This

average mass is the atomic mass of pennium.

17

Observations: Fill in the Data table.

Isotope 1 Isotope 2 Total1. Number of Particles 2. Mass of Isotope 3. Percent Abundance 4. Relative Abundance 5. Relative Mass

6. Average Mass (Atomic Mass of Pennium): ____________

Discussion: (answer on a separate sheet of paper)

1. a. Based on your experimental data, which isotope is the average atomic mass closest to? b. Explain your answer in terms of percent abundance.

2. The table below gives information about two isotopes of element X.

Isotope Mass Relative AbundanceX-10 10.01 19.91 %X-11 11.01 80.09 %

Calculate the average atomic mass of element X.• Show a correct numerical setup. • Record your answer • Express your answer to the correct number of significant figures

3. Naturally occurring elemental carbon is a mixture of isotopes. The percent compositionof the two most abundant isotopes is listed below.

• 98.93% of the carbon atoms have a mass of 12.00 atomic mass units.• 1.07% of the carbon atoms have a mass of 13.00 atomic mass units.

Calculate the average atomic mass of carbon. Describe, in terms of subatomic particles found in the nucleus, one difference between the

nuclei of carbon-12 atoms and the nuclei of carbon-13 atoms. The response must include both isotopes.


18


Lab 7 – Flame Test

Pre-lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. What is a line spectrum?3. How can you use the Bohr model to explain the line spectrum of a given element?4. What is a flame test used to specifically identify?5. Do electrons all come from the same shell when they become excited?6. Write the ground state electron configuration for an atom of calcium.7. Write three possible excited state configurations for an atom of calcium.

Problem: How can light provide information about electrons?

Introduction: When an electron is in a state of lowest possible energy, it is said to be in its ground

state. If the electron gains energy due to the use of heat, light or a flame, the electron gains energy and it moves to an excited state. When it returns back to its ground state, it loses energy and emits the energy in the form of light. Each atom or ion emits specific colors of light when it falls back to the ground state. Therefore, atoms and ions can be identified by means of a flame test – placing the atom or ion in a flame, and observing what colors are emitted.

Materials: Nichrome wire, 4” Salt Compounds:

Calcium chlorideSodium chloridePotassium chlorideCopper(II) chlorideStrontium chlorideLithium chlorideBarium chloride

Distilled water Beaker Wooden splint Dilute HCl – 1M

Procedure: Follow the procedure set out by your teacher.

Data Table: Create a table. You must include columns for the metal compounds, metal ions, color of flame, and the wave length.

19

Discussion: 1. What metal ion is in the unknown solution?2. How would you characterize the flame test with respect to its sensitivity? What

difficulties could there be when identifying ions by the flame test?

Base your answers to questions 3 and 4 on the diagram below, which shows bright-line spectraof selected elements.

3. Identify the two elements in the unknown spectrum.4. Explain how a bright-line spectrum is produced, in terms of excited state, energy

transitions, and ground state.5. A student performed flame tests on several unknowns and observed that they all were

shades of red. What should the student do to correctly identify theses substances? Explain your answer.

6. Some stores sell jars of “fireplace crystals.” When sprinkled on a log, these crystals make the flames orange, red, green, and violet. Explain how these crystals can change the flame’s color. What ingredients would you expect them to contain?


20


Lab 8 – Ionization Energies of Elements on the Periodic Table: Periods

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.

1. Write a hypothesis about the problem question.2. Define the ionization energy of an element.3. In what unit is ionization energy measured?4. Do non-metals have high or low ionization energies? Explain your answer.5. How is ionization energy related to the atomic radius of an element?

Problem: What is the general trend among elements within a period with respect to their ionization energies?

Introduction: The First Ionization Energy of an element is the amount of energy required to remove an electron from each atom in one mole of atoms of the element. The ionization energy shows characteristic patterns in the groups and periods of the Periodic Table. The value of the ionization energy depends on the chemical properties of the elements and vice versa.

Materials: Chemistry reference tables, graph paper and writing materials.

Procedure: 1. Using your Reference Tables, create a data table showing the ionization energies of elements

in periods 2 and 3.2. With the appropriate scaling of your graph paper, plot a line graph of ionization energy

against atomic number for each of the periods stated above. Use different symbols or colors for the elements in each period.

3. Label your graph. Staple your graph paper to the lab sheet.

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.1. The amount of energy required to remove the outermost electron from a gaseous atom in the ground state is known as(1) first ionization energy(2) activation energy(3) conductivity(4) electronegativity2. From which of these atoms in the ground state can a valence electron be removed using the least amount of energy?(1) nitrogen (3) oxygen(2) carbon (4) chlorine

21

3. Based on Reference Table S, which of the following atoms requires the least energy for the removal of the most loosely bound electron?(1) Sn (3) Be(2) Sr (4) Br4. The elements in the Periodic Table are arranged in order of increasing(1) atomic number (3) atomic radius(2) mass number (4) neutron number5. Based on your graph, describe the trend in the ionization energy of these elements as the atomic number increases.6. Do metals tend to have high or low ionization energies? Explain your answer.7. Explain, in terms of ionization energies, why metals and non-metals tend to combine to form ionic bonds.8. How can the ionization energy of an element help you predict the nature of the element?9. Explain, in terms of atomic structure, why group 18 elements have the highest ionization energies.

Conclusion: Answer the problem in complete sentences.

22


Lab 9 – Ionization Energies of Elements on the Periodic Table: Groups

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Describe the following trends:

a. Describe the trend in electronegativity as you go across Period 2.b. Describe the trend in electronegativity as you go down Group 16.c. Describe the trend in ionization energy as you go across Period 2.d. Describe the trend in atomic radius as you go down Group 15.

Problem: What is the general trend among elements within a group with respect to their ionization energies?

Introduction: The First Ionization Energy of an element is the amount of energy required to remove an electron from each atom in one mole of atoms of the element. The ionization energy shows characteristic patterns in the groups and periods of the Periodic Table. The value of the ionization energy depends on the chemical properties of the elements and vice versa.

Materials: Chemistry reference tables, graph paper and writing materials.

Procedure:1. Using you Reference Tables, create a data table showing the ionization energies of elements

in groups 1, 2, & 15.2. With the appropriate scaling of your graph paper, plot a line graph of ionization energy

against atomic number for each of the groups stated above. Connect the points within each group. Use different colors or symbols for the elements in each group.

3. Label your graph. Staple your graph paper to the lab sheet.

23

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.

1. Elements Q, X, and Z are in the same group on the Periodic Table and are listed in order of increasing atomic number. The melting point of element Q is –219°C and the melting point of element Z is –7°C. Which temperature is closest to the melting point of element X?(1) –7°C (3) –219°C(2) –101°C (4) –226°C2. On the present Periodic Table of the Elements, the elements are arranged according to increasing(1) number of oxidation states(2) number of neutrons(3) atomic mass(4) atomic number3. Which list of elements from Group 2 on the Periodic Table is arranged in order of increasing atomic radius?(1) Be, Mg, Ca (3) Ba, Ra, Sr(2) Ca, Mg, Be (4) Sr, Ra, Ba4. The data table below shows elements Xx, Yy, and Zz from the same group on the Periodic Table.

Element

Atomic Mass(atomic mass units)

Atomic Radius (pm)

Xx 69.7 141Yy 114.8 ?Zz 204.4 171

What is the most likely atomic radius of element Yy?(1) 103 pm (3) 166 pm(2) 127 pm (4) 185 pm

5. Based on your graph, describe the trend in the ionization energy going down a group on the periodic table as the atomic number increases.6. Explain your answer to the previous question in terms of energy levels.7. Explain what effect the increase in the number of electrons of each successive element in a group has on the ionization energy.8. Explain, in terms of atomic structure, why cesium has a lower first ionization energy than rubidium.9. Radium does not have an ionization energy listed on the Reference Tables. Based on your graph, predict what it could be. Justify your answer.


24


Lab 10 – Periodic Properties Part A – Density

Pre-Lab Questions: Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Define group.3. How are elements arranged on the periodic table?4. Describe the trend in metallic character as you go down group 14.5. As the elements of Group 14 are considered from top to bottom explain what happens to

a. atomic radius of each successive elementb. ionization energy of each successive element

6. Classify each element in Group 14.

Problem: How does the density vary in a group on the Periodic Table?

Introduction:When the elements are arranged in order of increasing atomic number, they exhibit a

periodic recurrence of properties. This fact led to the grouping of elements as seen in the periodic table. Elements in vertical columns of the periodic table form groups (families) with similar physical and chemical properties. These similarities are due, in large part, to the fact that all the elements within a group have the same outer shell electron configuration. You can also find periodic trends in certain properties, such as density, among the elements from the same given group. In addition, compounds that contain elements from the same group can display trends in properties as solubility.

Materials: Triple beam balance, 4 small test tubes, test tube rack, 10 mL graduated cylinder , weighing paper, lead shot (Pb), silicon (Si), tin (Sn) distilled water.

Procedure:Determine the volume of the tin, lead, and silicon samples by the water displacement method. You will need to measure the mass of each sample. Calculate the density of each sample using the formula D = m / v. Record the data in Data Table 1. Note the appearance of these elements.

1. Put on your goggles.2. Weigh a sheet of weighing paper on a balance. Measure its mass to the nearest 0.01 g. Place

a splintful of tin (Sn) on the weighing paper. Measure its mass to the nearest 0.01 g and record this mass in Data Table 1.

3. Add your sample to 5 mL of water. Record the volume to the nearest 0.1 mL.4. Repeat steps 2 and 3 for lead shot (Pb) and silicon (Si).

Data/ Calculations:

25

1. Calculate and record the densities of the tin, silicon and lead samples in Data Table 1. In the space below the data table, show all work and write the appropriate units.

2. Prepare a graph of density versus period number for tin, silicon, and lead. DATA TABLE 1

Silicon (Si) Tin (Sn) Lead (Pb)

mass of weighing papermass of sample (g)volume of water (mL)volume of water + sample (mL)volume of sample (mL)density of sample (g/mL) Period number

Calculations:Silicon Tin Lead

Discussion: On a separate sheet of paper, answer the following questions in complete sentences. Skip a line between each answer.

1. Based on your graph, estimate the density of germanium (Ge). Germanium is located in Period 4.

2. Why is it necessary to find the mass of each element first, and then find the volume? What error could be introduced if you did it the other way around?

3. Compare your estimate with the accepted density of germanium. Give possible sources of errors.

4. Calculate the percent error between your estimated value and the accepted value for the density of germanium. Show all work.

5. Describe the trend between density and period number.

Conclusion: On a separate sheet of paper, answer the problem question in one or two complete sentences. The conclusion must be precise and must be based on your observations.

26


Lab 11 – Formulas of Ionic Compounds

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Complete Data Table A.

Problem: How can we determine the formula for different ionic compounds?

Introduction: A chemical formula is a combination of symbols and numerical subscripts. The formula represents the composition of a compound. In an ionic compound, these symbols represent the proportions of each element in the compound.

When atoms acquire a charge, they are called ions. Ions made up of more than one atom are called polyatomic ions. We can treat these groups of atoms together as one single entity. Atoms tend to form ions in order to satisfy the octet rule. For example, oxygen, with 6 valence electrons, tends to gain 2 electrons and form a -2 ion.

When determining the formula for a compound, you must balance the positive charges in the cation with the negative charges in the anion. Since they represent proportions, these formulas for ionic compounds should always be reduced to their simplest whole numbers. As we will see later on, this is not the case for covalent compounds!

Materials:Scissors, pen and paper, sheet of ion models

Procedure:1. Cut out each of the “ion” squares from the sheet provided by your teacher.2. Construct the formula for the ionic compound between sodium and chlorine using the ion

squares. Arrange the ion squares on a separate sheet of paper and paste them to your paper. Label the name of the compound underneath the squares. Your compound must have a balanced positive and negative charge and should use the smallest whole number ratios.

3. Complete Data Table B for the compound between sodium and chlorine.4. Repeat for the compounds formed between:

a. magnesium and chlorineb. aluminum and brominec. sodium and oxygend. iron(II) and sulfure. iron(III) and chlorinef. ammonium ion and sulfur

g. aluminum and oxygenh. iron(III) and nitratei. sodium and phosphatej. iron(II) and sulfatek. potassium and sulfatel. magnesium and phosphate

27

Observations: Attach your finished sheets with the ion square compounds and Data Tables A and B.

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.1. a. How does a metal become an ion?

b. How does a non-metal become an ion?2. a. When a metal becomes an ion, what is its net charge?

b. When a non-metal becomes an ion, what is its net charge?3. a. When an atom becomes an ion, it usually ends up with _____ valence electrons.

b. Ions tend to have the same electron configuration as ________ ________.4. a. When a metal becomes an ion, does its atomic radius increase or decrease? Why?

b. When a non-metal becomes an ion, does its atomic radius increase or decrease? Why?5. What is the chemical formula for copper(II) hydroxide?

(1) CuOH (3) Cu2(OH)(2) CuOH2 (4) Cu(OH)2

6. What is the correct Lewis electron-dot structure for the compound magnesium fluoride?

7. What is the correct IUPAC name for the compound NH4Cl?(1) nitrogen chloride(2) nitrogen chlorate(3) ammonium chloride(4) ammonium chlorate

8. Which substance has a chemical formula with the same ratio of metal ions to nonmetal ions as in potassium sulfide?(1) sodium oxide(2) sodium chloride(3) magnesium oxide(4) magnesium chloride

9. What is the chemical formula for tin(II) fluoride?10. Draw an electron-dot diagram for calcium oxide (an ionic compound).


28

Data Table AElement Draw Lewis

Structure for Element

Name Ion Draw Lewis Structure for Ion

calcium

calcium

aluminum

bromine

chlorine

magnesium

oxygen

potassium

sodium

sulfur

29

Data Table BName of Elements

Name Compound Write Formula of Compound

Draw Lewis Structure of Compound

sodium

chlorine

magnesium

chlorine

aluminium

bromine

sodium

oxygen

iron(II)

sulfur

iron(III)

chlorine

ammonium

sulfur Name of Name Compound Write Draw Lewis Structure of

30

Elements Formula of Compound

Compound

aluminium

oxygen

iron(III)

nitrate

sodium

phosphate

iron(II)

sulfate

potassium

sulfate

magnesium

phosphate

31


Lab 12 – Formulas of Covalent Compounds

Pre-lab questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Complete Data Table A.

Problem: How can we determine the formula for different molecular compounds?

Introduction: A chemical formula is a combination of symbols and numerical subscripts. The formula represents the composition of a compound. In a molecular compound, these symbols represent the number of atoms of each element in a single molecule of the substance.

Molecular compounds are formed when atoms form covalent bonds with each other. Each covalent bond represents a pair of shared electrons. Usually, each atom contributes one electron to the bond. Atoms tend to form molecular compounds in order to satisfy the octet rule. For example, fluorine, with 7 valence electrons, tends to form one covalent bond. By sharing one electron, it can reach a stable octet.

When determining the formula of a compound, it is helpful to draw the Lewis-dot diagrams first. By bonding the atoms together, you can determine how many of each atom is necessary to make a stable octet.

Procedure:1. Cut out each of the element squares from the sheet provided by your teacher.2. Construct the formula for the molecular compound between hydrogen and chlorine using the

element squares. Arrange the element squares on a separate sheet of paper and paste them to your paper. Label the name of the compound underneath the squares. Your atoms must be bonded together so that each element has a complete outer shell.

3. Complete Data Table B for the compound between hydrogen and chlorine.4. Repeat for the compounds or molecules formed between:

a. hydrogen and oxygenb. hydrogen and nitrogenc. hydrogen and carbond. hydrogen and hydrogene. oxygen and oxygenf. nitrogen and nitrogen

g. carbon and bromineh. phosphorus and chlorinei. hydrogen and iodinej. fluorine and fluorinek. carbon and oxygen (CO2)l. hydrogen cyanide (HCN)

Observations: Attach your finished sheets with the element square compounds and Data Tables A and B.

32

Discussion: Answer on a separate sheet of paper. For all multiple choice questions, include a 1 sentence explanation of your answer.

1. Which type of bonding is found in all molecular substances?(1) covalent bonding (3) ionic bonding(2) hydrogen bonding (4) metallic bonding2. What is the total number of pairs of electrons shared in a molecule of N2?(1) one pair (3) three pairs(2) two pairs (4) four pairs3. Given the Lewis electron-dot diagram:

Which electrons are represented by all of the dots?(1) the carbon valence electrons, only(2) the hydrogen valence electrons, only(3) the carbon and hydrogen valence electrons(4) all of the carbon and hydrogen electrons4. Covalent bonds are formed when electrons are(1) transferred from one atom to another(2) captured by the nucleus(3) mobile within a metal(4) shared between two atomsBase your answers to the question below on your knowledge of chemical bonding and on the Lewis electron-dot diagrams of H2S, CO2, and F2 below.

5. Which atom, when bonded as shown, has the same electron configuration as an atom of argon?6. Draw a correct Lewis electron-dot structure for each of the following:a An atom of hydrogenb An atom of nitrogenc A molecule of ammonia (NH3)7. Draw a Lewis electron-dot diagram for a molecule of phosphorus trichloride, PCl3.

Conclusion: Answer the problem question using complete sentences.

33

Data Table AElement Draw Lewis

Structure for Element

How many bonds must this element for it to be stable?

Can this element form double and triple bonds?

Hydrogen One No

Oxygen

Nitrogen

Chlorine

Fluorine

Carbon

Bromine

Iodine

Phosphorus

34

35

Data Table BName of Elements


Write Formula of Compound/ Molecule

Name Compound

Hydrogen

Chlorine

Hydrogen

Oxygen

Hydrogen

Nitrogen

Hydrogen

Carbon

Hydrogen

Hydrogen

Oxygen

Oxygen

Nitrogen

Nitrogen

36

Name of Elements


Write Formula of Compound/ Molecule

Name Compound

Carbon

Bromine

Phosphorus

Chlorine

Hydrogen

Iodine

Fluorine

Fluorine

Carbon

Oxygen

Hydrogen

Cyanide (CN)

37


Lab 13 – Solubility and Bond Type

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Define the following words: soluble, insoluble, solubility, miscible, immiscible.3. Draw electron-dot diagrams for the following molecules and name each one:

a. H2Ob. CCl4

c. NH3

d. Cl2

e. HFf. CO2

Problem: How can we predict whether a compound has polar or non-polar bonds?

Introduction: Molecular compounds may contain polar covalent or non-polar covalent bonds. Some ways to predicts whether a substance has polar covalent or non-polar covalent bonds is to measure the solubility, electrical conductivity, melting point and the tendency of a liquid to rise in a narrow space. In this lab we will focus on the solubility of these compounds. Substances with polar covalent bonds tend to dissolve in other substance with polar covalent bonds; substances with non-polar covalent bonds tend to dissolve in other substances with non-polar covalent bonds. This gives rise to the phrase like dissolves like. When we are dealing with two liquids, we often substitute the word miscible for soluble and the word immiscible for insoluble.

Materials: test tubes, test tube rack, tap water with blue food coloring, ethanol with red food coloring, corn oil, baby oil

Procedure:1. Pour 5 mL of water into a test tube.2. Add 5 mL of ethanol to the same test tube.3. Observe whether or not the two liquids are miscible. Record your observations in the data

table.4. Repeat steps 1-3 for each combination of the four liquids listed in your materials.

Observations:Liquids Water Ethanol Corn oil Baby oilBaby oilCorn oilEthanolWater

38

Discussion:1. Identify the bond type of each of the four liquids you used. Explain your reasoning for each

substance.2. For each of these four liquids, determine whether they contain symmetrical or asymmetrical

molecules. Explain your reasoning.3. Hexane (C6H14) and water do not form a solution. How can you explain this phenomenon?4. Base your answer to question 3 on the information below.

Naphthalene, a nonpolar substance that sublimes at room temperature, can be used to protect wool clothing from being eaten by moths.Explain why naphthalene is not expected to dissolve in water.

5. What would be a characteristic of cleaning agents that are effective at dissolving oily stains?6. How are some cleaning agents able to dissolve polar and non-polar substances?7. Base your answers to question 7 on the information below.

Testing of an unknown solid shows that it has the properties listed below. low melting point nearly insoluble in water nonconductor of electricity relatively soft solid

State the type of bonding that would be expected in the particles of this substance.8. For each of the molecules you drew in pre-lab question 6, identify the substance as polar or

non-polar, and explain why in terms of symmetry.


39


Lab 14 – Heating Curve

Pre-lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Define: melting, vaporization, freezing, condensation, boiling, kinetic energy, potential

energy, heat of fusion, heat of vaporization.3. Draw particle diagrams for water in the solid, liquid and gas phases.4. Describe the difference between the three phases.5. Define temperature.6. What happens to the temperature of a substance when it is undergoing a phase change?7. Describe the energy change in a substance when it is being heated from -20 °C to 0 °C.8. Describe the energy change in a substance when it is melting at a constant temperature.9. What is a best-fit line?

Problem: How much energy is needed to heat water from a solid to a vapor?

Introduction:A heating curve is a graph of the time it takes to heat a substance from a solid to a gas. It also shows the temperature changes over this period of time. The heating curve represents the data taken while a substance is being heated constantly. This graph can be separated into various regions based upon the changes the substance undergoes during each segment. The substance will also undergo phase changes during this time.

Procedure:1. Use the data in the table on p. 503 to plot a heating curve of temperature vs. time for a 180-g

sample of water as it is heated at a constant rate from -20 °C to 120 °C. Time is the independent variable, and should go on the x-axis.

2. Draw a best-fit line through the points.3. Name your graph.4. Label the following points on your graph:

a. Time = 0.0 is Point A.b. Time = 1.0 is Point B.c. Time = 2.5 is Point C.d. Time = 10.5 is Point D.e. Time = 24.0 is Point E.f. Time = 25.0 is Point F.

5. On your graph, label the phase or phase change of each segment.

40

Discussion:1. For each of the five segments on your graph:

a. Describe, in terms of particle behavior, what is happening to the substance during that time.

b. Describe, in terms of changes in energy, what is happening to the substance during that time.

c. Using your Reference Table, calculate the amount of heat required for that segment of the graph. (Hint: You can NOT use the same formula for all five segments.)

2. How does the length of time needed to pass through each region relate to the amount of heat absorbed?

3. What would the heating curve of ethanol look like? Make a rough sketch of ethanol’s curve from -120 °C to 90 °C. Ethanol melts at -114 °C and boils at 78 °C.

4. Look up the melting and boiling points for bromine. On the same graph as ethanol, make a rough sketch of bromine’s heating curve.

5. Given the graph below that represents the uniform cooling of a sample of lauric acid starting as a liquid above freezing point.

a Which line segment represents a phase change, only?b What is the melting point of lauric acid?c At which point do the particles of lauric acid have the highest average kinetic energy?d Name the phase change that takes place during this 10-minute cooling time.


41


Lab 15 – A Hot Peanut

Pre-Lab Questions (Answer in complete sentences)Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. a) What is heat?

b) Differentiate between heat and temperature.3. What is the unit for heat?4. What is the specific heat of water?5. Why shouldn’t the thermometer touch the can?

Problem: How can we determine the amount of heat contained in a peanut?

Materials (per group)triple-beam balance 1 roasted peanutempty aluminum soft-drink can ring standgraduated cylinder butane lighterfoil-covered cork stopper with tack ringthermometer with clamp tap water

Procedure:1. Put on your goggles and apron.2. Split a whole peanut into two halves. Find the mass of one peanut half on the triple-beam

balance. Record the mass in the data table on the next page.3. Carefully press the peanut half lengthwise onto the tack on the cork stopper. Be careful not

to prick your finger. Set aside the cork.4. Weigh the can. Record data.5. Fill the can with 100 mL of tap water. Record.6. Weigh the can with water. Record.7. Place the water-filled can on the ring stand.8. Attach the thermometer to the ring stand so that the thermometer bulb rests in the water in

the can. The thermometer should not touch the bottom of the can. Record the temperature of the water in the data table.

9. Place the cork with the peanut on the base of the ring stand under the center of the can as shown in the diagram on this page. Adjust the height of the ring so that the bottom of the can is about two centimeters above the peanut.

10. Slide the cork out from under the can. Light the peanut using the butane lighter. Slide the cork back under the can.

11. When the peanut flame burns out, record the temperature of the water in the data table.

42

12. Calculate the mass of the water in your can without using the triple beam balance. Assume the density of the water is one gram per milliliter (1 g/ mL). Record the mass in the data table.

13. Calculate the change in temperature of the water. Record your answer in the data table.

Observations:

Mass of one-half peanutMass of can + waterMass of canMass of water Volume of waterInitial temperature of waterFinal temperature of waterChange in temperature

Discussion:1. Write the equation for calculating heat absorbed.2. Calculate the amount of heat absorbed by the water in joules using the following equation:

a. heat absorbed = mass of water specific heat of water change in temperature

3. Where does the heat that the water gains originate?4. Does the number of joules absorbed by the water represent all of the heat released by the

burning peanut? Explain your answer.5. Which form of energy is converted to heat energy in this reaction?


43


Lab 16 – Boyle’s Law

Problem: How can we test Boyle’s Law?

Pre-Lab Questions:Read through the problem, introduction and procedure. Then answer the following questions on a separate sheet of paper.1. Write a hypothesis about the problem question.2. Define Boyle’s Law.3. How can we describe this relationship?4. What conditions must be held constant in order for Boyle’s Law to be accurate?5. What is the formula that can be used to solve Boyle’s Law problems?

Materials: Boyle’s Law Apparatus, graph paper, ruler.

Procedure:1. Create a Data Table to allow you to test Boyle’s Law:

P1V1 = P2V2 = P3V3 = constant (k).2. Use the Boyle’s Law apparatus on the following website to measure the pressure and volume

of a system.

http://www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/gaslaw/boyles_law_new.html

3. Repeat the step at least 5 times at different volumes.4. Complete your data table.5. Prepare a graph of Pressure vs. Volume for the system you have examined.

Observation:Attach your Data Table and Graph.

44

Discussion:1. A gas has a volume of 50 mL, at a pressure of one atmosphere. Increase the volume to 100

mL, and the temperature remains constant. What is the new pressure?

2. A sample of neon gas occupies 0.220 L at 0.860 atm. What will be its volume at 29.2 kPa pressure? (Hint: See Reference Table p. 1)

3. A fixed amount of oxygen gas is held in a 1.00 L tank at a pressure of 3.50 atm. The tank is connected to an empty 2.50 L tank by a tube with a valve. After this valve has been opened and the oxygen is allowed to flow freely between the two tanks at a constant temperature, what is the final pressure in the system? (Hint: Draw and label a diagram of before and after.)

Base your answers to questions 4 and 5 on the diagram below, which shows a piston confining a gas in a cylinder.

4. Using the set of axes provided in your answer booklet, sketch the general relationship between the pressure and the volume of an ideal gas at constant temperature. [1]

5. The gas volume in the cylinder is 6.2 milliliters and its pressure is 1.4 atmospheres. The piston is then pushed in until the gas volume is 3.1 milliliters while the temperature remains constant.a In the space provided in your answer booklet, calculate the pressure, in atmospheres, after the change in volume. Show all work. [1]b Record your answer. [1]

Conclusion: Answer the problem question using complete sentences.

45

Documents

To do list:s3.amazonaws.com/.../Chem_1_lab_manual_v4.docx · Web viewIdentify one apparatus used in the lab to accurately measure mass. What units does this apparatus use? What is