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CHE107-First Session
Dr. Berrin Kursun
CONTACT
• Engineering D Building-308
• Office Hours: ????
Course Book
Chemistry The Central Science
13th edition (Global Edition)
Brown, LeMay, Bursten…..
Pearson Publishing
Fundamentals
• 80% Attendance
• 1 midterm, 1 final
• Grading: To be announced
Chapter 1
Introduction: Matter and Measurement
In chemistry, we study matter, its properties, and its behavior.
Classification of Matter
Matter
And
Measurement
Classification of Matter
• Matter is made of atoms.
• 114 elements.
• About 90% available from natural sources
• Compounds are comprised of two or more elements.
• Molecules are the smallest units of compounds.
States of Matter• What can you say about different states of water by just
looking at this picture?
Properties and Changes of Matter
Types of Properties
• Physical Properties…
– Can be observed without changing a substance into another substance.
◦ Boiling point, density, mass, volume, etc.
• Chemical Properties…
– Can only be observed when a substance is changed into another substance.
◦ Flammability, corrosiveness, reactivity with acid, etc.
Types of Properties
• Intensive Properties…
– Are independent of the amount of the substance that is present.
◦ Density, boiling point, color, etc.
• Extensive Properties…
– Depend upon the amount of the substance present.
◦ Mass, volume, energy, etc.
Types of Changes
• Physical Changes (Reversible)
– These are changes in matter that do not change the composition of a substance.
◦ Changes of state, temperature, volume, etc.
• Chemical Changes (Sometimes Irreversible)
– Chemical changes result in new substances.
◦ Combustion, oxidation, decomposition, etc.
Chemical or Physical?
• Cooking?
• Laundary?
• Yogurt fermentation?
Chemical Reactions
In the course of a chemical reaction, the reacting substances are converted to new substances.
• A chemical change: decomposition of ammonium dichromate
Separation of Mixtures
Filtration
In filtration, solid substances are separated from liquids and solutions.
Distillation
Distillation uses differences in the boiling points of substances to separate a homogeneous mixture into its components.
Chromatography
This technique separates substances on the basis of differences in solubility in a solvent.
Units of Measurement
SI Units
• Système International d’Unités
• A different base unit is used for each quantity.
Metric System
Prefixes convert the base units into units that are appropriate for the item being measured.
Volume
• The most commonly used metric units for volume are the liter (L) and the milliliter (mL).
– A liter is a cube 1 decimeter (dm) long on each side.
– A milliliter is a cube 1 centimeter (cm) long on each side.
Temperature
By definition temperature is a measure of the average kinetic energy of the particles in a sample.
Temperature• In scientific measurements,
the Celsius and Kelvin scales are most often used.
• The Celsius scale is based on the properties of water.
– 0 C is the freezing point of water.
– 100 C is the boiling point of water.
Temperature
• The kelvin is the SI unit of temperature.
• It is based on the properties of gases.
• There are no negative Kelvin temperatures.
• K = C + 273.15
Temperature
• The Fahrenheit scale is not used in scientific measurements.
• F = 9/5(C) + 32
• C = 5/9(F − 32)
Derived Units
• Density is a physical property of a substance.
• It has units (g/mL, for example) that are derived from the units for mass and volume.
d =m
V
Uncertainty in Measurement
Uncertainty in Measurements
Different measuring devices have different uses and different degrees of accuracy.
Accuracy versus Precision
• Accuracy refers to the proximity of a measurement to the true value of a quantity.
• Precision refers to the proximity of several measurements to each other.
Significant Figures
• The term significant figures refers to digits that were measured.
• When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers.
Significant Figures
1. All nonzero digits are significant.
2. Zeroes between two significant figures are themselves significant.
3. Zeroes at the beginning of a number are never significant.
4. Zeroes at the end of a number are significant if a decimal point is written in the number.
Significant Figures
• When addition or subtraction is performed, answers are rounded to the least significant decimal place.
• When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation.
Dimensional Analysis
• We use dimensional analysis to convert one quantity to another.
• Most commonly, dimensional analysis utilizes conversion factors (e.g., 1 in. = 2.54 cm)
1 in.
2.54 cm
2.54 cm
1 in.or
Dimensional Analysis
Use the form of the conversion factor that puts the sought-for unit in the numerator:
Given unit = desired unitdesired unit
given unit
Conversion factor =How many
desired units in a given unit.
Dimensional Analysis
• For example, to convert 8.00 m to inches,
– convert m to cm
– convert cm to in.
8.00 m 100 cm
1 m
1 in.
2.54 cm= 315 in.
Application Questions
• 1)The recommended adult dose of Elixophyllin , a drug used to treat asthma, is 6.00 mg/kg of body mass. Calculate the dose in milligrams for a 115-lb person. 1 lb = 453.59 g.
• A) 24
• B) 1521
• C) 1,5
• D) 313
• E) 3,1E+05
2) The density of air under ordinary conditions at 25 °C is 1.19 g/L. How many kilograms of air are in a room that measures 11.0 ft x 11.0 ft and has an 10.0 ft ceiling? 1 in. = 2.54 cm (exactly);
• 1 L = 103 cm3
• A) 3.66
• B) 0.152
• C) 4.08 × 104
• D) 0.0962
• E) 40.8
Significant figures
3) The number 0.00430 has __________ significant figures.• A) 2• B) 3• C) 5• D) 4• E) 64) How many significant figures are in the measurement 5.34 g?• A) 1• B) 2• C) 4• D) 3• E) 5
55) In which one of the following numbers are none of the zeros
significant?
A) 100.0
B) 1065
C) 0.0100
D) 1.003450
E) 0.00001
52) How many significant figures should be retained in the result
of the following calculation?
12.00000 × 0.9893 + 13.00335 × 0.0107
A) 2
B) 3
C) 4
D) 5
E) 6
Significant figures
5)Round the number 0.007222 to three significant figures.• A) 0.007• B) 0.00722• C) 0.0072• D) 0.00723• E) 0.0072256) Round the number 3456.5 to two significant figures.• A) 3400.0• B) 3400• C) 3000• D) 3500• E) 3000.0
Properties
7) An iron mine produces 1.67E+04 tons of raw ore per day. If the ore is 26.39% elemental iron, the mine produces __________ pounds of elemental iron per year. (Assume the mine operates 365 days per year.) • A) 1.221 E+10• B) 8.814 E+06• C) 3.217 E+09• D) 1.611 E+04• E) 3.66E+11
8) The law of constant composition says __________.• A) that the composition of a compound is always the same• B) that all substances have the same composition• C) that the composition of an element is always the same• D) that the composition of a homogeneous mixture is always the same• E) that the composition of a heterogeneous mixture is always the same
9) Which of the following is an illustration of the law of constant composition?• A) Water boils at 100°C at 1 atm pressure.• B) Water is 11% hydrogen and 89% oxygen by mass.• C) Water can be separated into other substances by a chemical process.• D) Water and salt have different boiling points.• E) Water is a compound.
10) In the following list, only __________ is not an example of a chemical reaction.• A) dissolution of a penny in nitric acid• B) the condensation of water vapor• C) a burning candle• D) the formation of polyethylene from ethylene• E) the rusting of iron11) Gases and liquids share the property of __________.• A) compressibility• B) definite volume• C) incompressibility• D) indefinite shape• E) definite shape
12) Which one of the following is an intensive property?• A) mass• B) temperature• C) heat content• D) volume• E) amount
13) Of the following, only __________ is an extensive property.• A) density• B) mass• C) boiling point• D) freezing point• E) temperature
