unit 1 foundations review wednesday, october 13, 2010
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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