Unit 1 Foundations Review Wednesday, October 13, 2010

Unit 1 Foundations Unit 1 Foundations ReviewReview

Wednesday, October 13, 2010Wednesday, October 13, 2010

Key TermsKey Terms

SublimationSublimation sublimingsubliming DepositionDeposition depositingdepositing CondensationCondensation condensingcondensing EvaporatingEvaporating boilingboiling SolidificationSolidification freezingfreezing Liquification Liquification meltingmelting

Key Terms - MatterKey Terms - Matter

Pure SubstancePure Substance Element (atom) - periodic tableElement (atom) - periodic table

Compound – 2 or more atomsCompound – 2 or more atoms

MixtureMixture homogeneous (solution – same homogeneous (solution – same

throughout)throughout) Solute (smaller quantity) and solvent (larger )Solute (smaller quantity) and solvent (larger )

Heterogeneous (uneven distribution)Heterogeneous (uneven distribution) Suspension (settles over time)Suspension (settles over time) Colloid (see the different, but does not settle)Colloid (see the different, but does not settle)

Key Terms - ApplicationKey Terms - Application

Sea waterSea water coppercopper MilkMilk aluminum foilaluminum foil CalciumCalcium grain alcoholgrain alcohol Vitamin CVitamin C after-shave lotionafter-shave lotion Table saltTable salt dry ice (solid COdry ice (solid CO22)) BloodBlood iron nailiron nail

Classify each as a homogeneous Classify each as a homogeneous or heterogeneous mixture.or heterogeneous mixture.

bloodblood chocolate chip ice creamchocolate chip ice cream brass (a blend of copper and zinc)brass (a blend of copper and zinc) motor oilmotor oil Black CoffeeBlack Coffee

Classify each as an element or a Classify each as an element or a

mixturemixture.. SilverSilver Pine TreePine Tree Orange JuiceOrange Juice OxygenOxygen Iced TeaIced Tea AirAir

For the mixtures, classify each as For the mixtures, classify each as homogeneous or heterogeneous.homogeneous or heterogeneous.

SodaSoda Candle WaxCandle Wax FogFog InkInk EggEgg IceIce GasolineGasoline BloodBlood

Table sugar is dissolved in a hot Table sugar is dissolved in a hot cup of coffee.cup of coffee.

What is the solvent of the resulting What is the solvent of the resulting solution?solution?

What is the solute of the resulting What is the solute of the resulting solution?solution?

Chemical or Physical Change?Chemical or Physical Change?

Bending a piece of wire.Bending a piece of wire. Burning coalBurning coal Cooking a steakCooking a steak Cutting grassCutting grass Vinegar and baking soda mixing.Vinegar and baking soda mixing.

Ethanol and water will form a Ethanol and water will form a solution.solution.

How is it determined which one is the How is it determined which one is the solute and which one is the solvent?solute and which one is the solvent?

How would you determine if a piece How would you determine if a piece of cloth advertised as 50% wool and of cloth advertised as 50% wool and 50 % synthetic fiber was a 50 % synthetic fiber was a heterogeneous or homogeneous heterogeneous or homogeneous mixture?mixture?

Classify each as a chemical or Classify each as a chemical or physical property. Intensive or physical property. Intensive or

Extensive?Extensive? Reacts with waterReacts with water ductileductile RedRed flammableflammable 1.5 m long1.5 m long Resists corrosionResists corrosion malleablemalleable Boils at 88ºCBoils at 88ºC corrosivecorrosive Dissolves in gasolineDissolves in gasoline freezes at -freezes at -

17ºC17ºC Conducts electricity Conducts electricity

Classify as chemical or physical Classify as chemical or physical changechange

Alcohol evaporatingAlcohol evaporating an explosionan explosion A firefly lighting upA firefly lighting up Salt dissolving in waterSalt dissolving in water Digesting foodDigesting food Battery chargingBattery charging Ice meltingIce melting Hammering hot iron into a sheetHammering hot iron into a sheet

What are the four indicators of What are the four indicators of chemical change?chemical change?

Evidence of Chemical Change:Evidence of Chemical Change: Heat and lightHeat and light Change in colorChange in color Production of gasProduction of gas Precipitation of a solidPrecipitation of a solid

How do you know that each of How do you know that each of these is a chemical change?these is a chemical change?

Food spoilsFood spoils A foaming antacid tablet fizzes in A foaming antacid tablet fizzes in

water.water. A ring of scum forms around your A ring of scum forms around your

bathtub.bathtub. A firecracker explodesA firecracker explodes

Name the elements in each of the Name the elements in each of the following compounds.following compounds.

Ammonium Chloride (NHAmmonium Chloride (NH44Cl)Cl)

Potassium Permanganate (KMnOPotassium Permanganate (KMnO44))

Isopropyl Alcohol (CIsopropyl Alcohol (C33HH77OH)OH)

Calcium Iodide (CaICalcium Iodide (CaI22))

Identify the following as Identify the following as quantitative or qualitative.quantitative or qualitative.

A flame is hotA flame is hot A candle has a mass of 90 gA candle has a mass of 90 g Wax is softWax is soft A candle’s height decreases 4.2 A candle’s height decreases 4.2

cm/hrcm/hr

The Periodic TableThe Periodic Table

Period

Group or family

Properties of MetalsProperties of Metals Metals are good conductors of heat and electricity

Metals are malleable

Metals are ductile

Metals have high tensile strength

Metals have luster

PropertiesProperties of Nonmetalsof Nonmetals

Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element.

Nonmetals are poor conductors of heat and electricity Nonmetals tend to be brittle Many nonmetals are gases at room temperature

Conversion PracticeConversion Practice

Kilo- 1000 units

Hecto-

100 units

Deka- 10 units Base Unit Deci-

0.1units

Centi-

0.01units

Milli-0.001units

To convert to a smaller unit, move the decimal point to the right or multiply.

To convert to a larger unit, move the decimal point to the left or

divide.

Base UnitsBase Units

LengthLength - - metermeter - - mm MassMass - - gramsgrams or kilogram - or kilogram - gg TimeTime - - secondsecond - - ss TemperatureTemperature – – KelvinKelvin - - KK EnergyEnergy - - JoulesJoules- - JJ Volume Volume - - LiterLiter - - LL Amount of substanceAmount of substance - - molemole - - molmol

Metric UnitsMetric Units

How many decigrams are there in 0.822 micrograms?

0.822 µg= dg

1 µg

10-6 g 8.22 x 10-6

1 dg

10-1 g

Metric UnitsMetric Units

Calculate the number of kilograms in

7.66 x 105 grams.

7.66 x 105 g= m

1 g

103 kg 1.025 x 103

The Metric SystemThe Metric System

Easier to use because it is a decimal Easier to use because it is a decimal system.system.

Every conversion is by some power Every conversion is by some power of 10.of 10.

A metric unit has two parts.A metric unit has two parts. A prefix and a base unit.A prefix and a base unit. prefix tells you how many times to prefix tells you how many times to

divide or multiply by 10.divide or multiply by 10.

PrefixesPrefixes

kilo kilo kk 1000 times 1000 times deci deci dd 1/10 1/10 centi centi cc 1/100 1/100 milli milli mm 1/1000 1/1000 kilometer - about 0.6 mileskilometer - about 0.6 miles centimeter - less than half an inchcentimeter - less than half an inch millimeter - the width of a paper clip millimeter - the width of a paper clip

wire wire

VolumeVolume

calculated by multiplying L x W x H calculated by multiplying L x W x H Liter the volume of a cube 1 dm (10 Liter the volume of a cube 1 dm (10

cm) on a sidecm) on a side so 1 L = 10 cm x 10 cm x 10 cmso 1 L = 10 cm x 10 cm x 10 cm 1 L = 1 dm1 L = 1 dm33

1 mL = 1 cm1 mL = 1 cm33

Cube Cube RepresentationsRepresentations

1 m3 = 1 000 000 cm3

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 119

MassMass

Weight is a force. Mass is the amount Weight is a force. Mass is the amount of matter.of matter.

1gram is defined as the mass of 1 1gram is defined as the mass of 1 cmcm33 of water at 4 ºC. of water at 4 ºC.

1000 g = 1000 cm1000 g = 1000 cm33 of water of water 1 kg = 1 L of water1 kg = 1 L of water

MassMass

1 kg = 2.2 lbs1 kg = 2.2 lbs 1 g = 1 paper clip1 g = 1 paper clip 1 mg = 10 grains of salt or 2 drops of 1 mg = 10 grains of salt or 2 drops of

water.water.

ConvertingConverting

k h D d c m how far you have to move on this how far you have to move on this

chart, tells you how far, and which chart, tells you how far, and which direction to move the decimal place.direction to move the decimal place.

The box is the base unit, meters, The box is the base unit, meters, Liters, grams, etc.Liters, grams, etc.

ConversionsConversions

Change 5.6 m to millimetersChange 5.6 m to millimeters

k h D d c m

starts at the base unit and move three to the right.move the decimal point three to the right

56 00

ConversionsConversions

convert 25 mg to gramsconvert 25 mg to grams convert 0.45 km to mmconvert 0.45 km to mm convert 35 mL to litersconvert 35 mL to liters It works because the math works, It works because the math works,

we are dividing or multiplying by we are dividing or multiplying by 10 the correct number of times.10 the correct number of times.

k h D d c m

Conversions

Change 5.6 km to millimeters

k h D d c m

Which is heavier?Which is heavier?

it dependsit depends

DensityDensity

How heavy something is for its size.How heavy something is for its size. The ratio of mass to volume for a The ratio of mass to volume for a

substance.substance. D = M / VD = M / V Independent of how much of it you Independent of how much of it you

havehave gold - high densitygold - high density air low density.air low density.

Volume and DensityVolume and DensityRelationship Between Volume and Density for Identical Masses of Common Substances

Cube of substance Mass Volume Density Substance (face shown actual size) (g) (cm3) (g.cm3)

Lithium

Water

Aluminum

Lead

10 19 0.53

10 10 1.0

10 3.7 2.7

10 0.58 11.4

Density of Some Common SubstancesDensity of Some Common Substances

Density of Some Common Substance

Substance Density (g / cm3)

Air 0.0013* Lithium 0.53 Ice 0.917 Water 1.00 Aluminum 2.70 Iron 7.86 Lead 11.4 Gold 19.3

Density of Some Common Substance

Substance Density (g / cm3)

Air 0.0013* Lithium 0.53 Ice 0.917 Water 1.00 Aluminum 2.70 Iron 7.86 Lead 11.4 Gold 19.3

*at 0oC and 1 atm pressure

DensityDensity

D

M

Vensity

ass

olume

D = MV

M = D x V

V = MD

CalculatingCalculating

A piece of wood has a density of A piece of wood has a density of 0.93 g/mL and a mass of 23 g what 0.93 g/mL and a mass of 23 g what is the volume?is the volume?

Given: D = 0.93 g/ml and m = 23 Given: D = 0.93 g/ml and m = 23 gg

Wanted: volumeWanted: volume D = m/vD = m/v

rearrange formula: V = m/Drearrange formula: V = m/D

PracticePractice

A piece of wood has a mass of 11.2 g A piece of wood has a mass of 11.2 g and a volume of 23 mL what is the and a volume of 23 mL what is the density?density?

A piece of wood has a density of 0.93 A piece of wood has a density of 0.93 g/mL and a volume of 23 mL what is g/mL and a volume of 23 mL what is the mass?the mass?

Temperature is Average Kinetic EnergyTemperature is Average Kinetic Energy

Fast Slow“HOT” “COLD”

Kinetic Energy (KE) = ½ m v2

*Vector = gives direction and magnitude

Celcius & Kelvin Temperature Celcius & Kelvin Temperature ScalesScales

Temperature ScalesTemperature Scales

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 136

Measuring TemperatureMeasuring Temperature

Kelvin starts at absolute zero (-273 Kelvin starts at absolute zero (-273 º C)º C)

degrees are the same sizedegrees are the same size C = K -273C = K -273 K = C + 273K = C + 273 Kelvin is always bigger.Kelvin is always bigger. Kelvin can never be negative. Kelvin can never be negative.

273 K

Specific Specific HeatHeat

The amount of heat required to raise the temperature of one gram of substance by one degree Celsius.

Calculations involving Specific Calculations involving Specific HeatHeat

cp = ___q__ m x T

q = cp x m x T

cp = Specific Heat

q = Heat lost or gained

T = Temperature change

OR

ProblemsProblems

It takes 24.3 calories to heat 15.4 g It takes 24.3 calories to heat 15.4 g of a metal from 22 ºC to 33ºC. What of a metal from 22 ºC to 33ºC. What is the specific heat of the metal?is the specific heat of the metal?

Iron has a specific heat of 0.11 Iron has a specific heat of 0.11 cal/gºC. How much heat will it take to cal/gºC. How much heat will it take to change the temperature of 48.3 g of change the temperature of 48.3 g of iron by 32.4ºC?iron by 32.4ºC?

Accuracy and PrecisionAccuracy and Precision

MEASUREMENTMEASUREMENT

Types of MeasurementTypes of Measurement

QuantitativeQuantitative- use numbers to - use numbers to describedescribe

QualitativeQualitative- use description without - use description without numbersnumbers

4 feet4 feet extra largeextra large HotHot 100ºF100ºF

Scientists preferScientists prefer

Quantitative- easy check.Quantitative- easy check. Easy to agree upon, no personal bias.Easy to agree upon, no personal bias. The measuring instrument limits how The measuring instrument limits how

good the measurement is.good the measurement is.

Accuracy vs. PrecisionAccuracy vs. Precision Accuracy Accuracy - how close a - how close a

measurement is to the accepted measurement is to the accepted valuevalue

PrecisionPrecision - how close a series of - how close a series of measurements are to each othermeasurements are to each other

ACCURATE = CORRECT

PRECISE = CONSISTENT

DifferencesDifferences

Accuracy can be true of an individual Accuracy can be true of an individual measurement or the average of measurement or the average of several.several.

Precision requires several Precision requires several measurements before anything can measurements before anything can be said about it.be said about it.

examplesexamples

Let’s use a golf anaolgy

Accurate? No

Precise? Yes

Accurate? Yes

Precise? Yes

Precise? No

Accurate? Maybe?

Accurate? Yes

Precise? We cant say!

In terms of measurementIn terms of measurement

Three students measure Three students measure the room to be 10.2 m, the room to be 10.2 m, 10.3 m and 10.4 m 10.3 m and 10.4 m across.across.

Were they precise?Were they precise? Were they accurate?Were they accurate?

Percent ErrorPercent Error

Indicates accuracy of a Indicates accuracy of a measurementmeasurement

100literature

literaturealexperimenterror %

your value

accepted value

Percent ErrorPercent Error A student determines the density of a A student determines the density of a

substance to be 1.40 g/mL. Find the % substance to be 1.40 g/mL. Find the % error if the accepted value of the error if the accepted value of the density is 1.36 g/mL.density is 1.36 g/mL.

100g/mL 1.36

g/mL 1.36g/mL 1.40error %

% error = 2.9 %

MeasurementsMeasurements

How many numbers mean anything.How many numbers mean anything. When we measure something, we When we measure something, we

can (and do) always estimate can (and do) always estimate between the smallest marks.between the smallest marks.

21 3 4 5

MeasurementsMeasurements

The better marks the better we can The better marks the better we can estimate.estimate.

Scientist always understand that the Scientist always understand that the last number measured is actually an last number measured is actually an estimate.estimate.

21 3 4 5

Significant FiguresSignificant Figures Indicate precision of a Indicate precision of a

measurement.measurement.

Recording significant figuresRecording significant figures Significant figures in a measurement Significant figures in a measurement

include the known digits plus a final include the known digits plus a final estimated digitestimated digit

2.35 cm

Significant FiguresSignificant Figures

Counting Sig FigsCounting Sig Figs Count all numbers EXCEPT:Count all numbers EXCEPT:

Leading zeros -- Leading zeros -- 0.000.002525

Trailing zeros without Trailing zeros without a decimal point -- 2,5a decimal point -- 2,50000

4. 0.0804. 0.080

3. 5,2803. 5,280

2. 4022. 402

1. 23.501. 23.50

Significant FiguresSignificant Figures

Counting Sig Fig Examples

1.1. 23.50 23.50

2.2. 402 402

3.3. 5,28 5,2800

4. 0.04. 0.08080

4 sig figs4 sig figs

3 sig figs3 sig figs

3 sig figs3 sig figs

2 sig figs2 sig figs

Significant FiguresSignificant Figures

How many sig figs in the following How many sig figs in the following measurements?measurements?

458 g458 g 4085 g4085 g 4850 g4850 g 0.0485 g0.0485 g 0.004085 g0.004085 g 40.004085 g40.004085 g

Sig Figs.Sig Figs.

405.0 g405.0 g 4050 g4050 g 0.450 g0.450 g 4050.05 g4050.05 g 0.0500060 g0.0500060 g Next we learn the rules for Next we learn the rules for

calculations.calculations.

Significant FiguresSignificant Figures

Calculating Calculating

Multiply/DivideMultiply/Divide - The # with the fewest - The # with the fewest sig figs determines the # of sig figs sig figs determines the # of sig figs in the answer.in the answer.

(13.91g/cm3)(23.3cm3) = 324.103g

324 g

4 SF 3 SF3 SF

PracticePractice

4.5 / 6.2454.5 / 6.245 4.5 x 6.2454.5 x 6.245 9.8764 x .0439.8764 x .043 3.876 / 19833.876 / 1983 16547 / 71416547 / 714

Significant FiguresSignificant Figures Calculating Calculating

Add/SubtractAdd/Subtract - The # with the lowest - The # with the lowest decimal value determines the place of decimal value determines the place of the last sig fig in the answer.the last sig fig in the answer.

3.75 mL

+ 4.1 mL

7.85 mL

224 g

+ 130 g

354 g 7.9 mL 354 g

3.75 mL

+ 4.1 mL

7.85 mL

224 g

+ 130 g

354 g

PracticePractice

4.8 + 6.87654.8 + 6.8765 520 + 94.98520 + 94.98 0.0045 + 2.1130.0045 + 2.113 6.0 x 106.0 x 1022 - 3.8 x 10 - 3.8 x 1033 5.4 - 3.285.4 - 3.28 6.7 - .5426.7 - .542 500 -126500 -126

Significant FiguresSignificant Figures

5. (15.30 g) ÷ (6.4 mL)5. (15.30 g) ÷ (6.4 mL)

Practice Problems

= 2.390625 = 2.390625

g/mLg/mL

18.1 g18.1 g

6. 18.9 g

- 0.84 g18.06 g

4 SF 2 SF

2.4 g/mL2.4 g/mL2 SF

Significant FiguresSignificant Figures Calculating with Sig Figs (con’t)Calculating with Sig Figs (con’t)

Exact NumbersExact Numbers do not limit the # of sig figs in do not limit the # of sig figs in the answer.the answer.

Counting numbers: 12 studentsCounting numbers: 12 students Exact conversions: 1 m = 100 cmExact conversions: 1 m = 100 cm ““1” in any conversion: 1 in = 2.54 cm1” in any conversion: 1 in = 2.54 cm

Rounding rules Rounding rules

Look at the number behind the one Look at the number behind the one you’re rounding.you’re rounding.

If it is 0 to 4 don’t change it.If it is 0 to 4 don’t change it. If it is 5 to 9 make it one bigger.If it is 5 to 9 make it one bigger. Round 45.462 to four sig figs.Round 45.462 to four sig figs.

Scientific NotationScientific Notation

Converting into Sci. Notation:Converting into Sci. Notation: Move decimal until there’s 1 digit to its Move decimal until there’s 1 digit to its

left. Places moved = exponent.left. Places moved = exponent.

Large # (>1) Large # (>1) positive exponent positive exponentSmall # (<1) Small # (<1) negative exponent negative exponent

Only include sig figs.Only include sig figs.

65,000 kg 6.5 × 104 kg

Scientific NotationScientific Notation

7. 7. 2,400,000 2,400,000 gg

8. 8. 0.00256 kg0.00256 kg

9.9. 7 7 10 10-5-5 km km

10.10. 6.2 6.2 10 1044 mm mm

Practice Problems

2.4 2.4 10 1066 gg

2.56 2.56 10 10-3-3 kg kg

0.00007 km0.00007 km

62,000 mm62,000 mm

Scientific NotationScientific Notation

Calculating with Sci. NotationCalculating with Sci. Notation

(5.44 × 10(5.44 × 1077 g) ÷ (8.1 × 10 g) ÷ (8.1 × 1044

mol) =mol) =

(5.44EXPEXP

EEEE÷÷

EXPEXP

EEEE ENTERENTER

EXEEXE7) (8.1 4)

= 671.6049383 = 670 g/mol = 6.7 × 102 g/mol

Type on your calculator:

Scientific NotationScientific Notation

Calculating with Sci. NotationCalculating with Sci. Notation

(5.44 × 10(5.44 × 1077 g) ÷ (8.1 × 10 g) ÷ (8.1 × 1044

mol) =mol) =

= 671.6049383 = 670 g/mol = 6.7 × 102 g/mol

Type on your calculator:

2nd 2nd

loglog(5.44 2nd2nd

loglog÷÷) (8.1 x 4 ) =X 7

GraphsGraphs Circle graphs – Circle graphs –

compare parts in a compare parts in a wholewhole

Bar graphs – compare Bar graphs – compare quantitiesquantities

Line graphs – compare Line graphs – compare sets of data, show sets of data, show change and patterns change and patterns over time.over time.

0

20

40

60

80

100

1st Qtr 2nd Qtr 3rd Qtr 4th Qtr

East

West

North

ProportionsProportions

Direct ProportionDirect Proportion

Inverse ProportionInverse Proportion

xy

xy

1

y

x

y

x