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The Language of The Language of ChemistryChemistryThe Language of The Language of ChemistryChemistry
• CHEMICAL ___________CHEMICAL ___________ - - – pure substances that cannot be decomposed by pure substances that cannot be decomposed by
ordinary means to other substances.ordinary means to other substances.
SodiumBromine
Aluminum
The Language of The Language of ChemistryChemistryThe Language of The Language of ChemistryChemistry
• The elements, The elements, their names, and their names, and symbols are given symbols are given on theon the PERIODIC PERIODIC TABLETABLE
• How many How many elements are elements are there?there?
Glenn Glenn SeaborgSeaborg
(1912-1999)(1912-1999)• Discovered 8 Discovered 8
new elements.new elements.
• Only living Only living person for person for whom an whom an element was element was named.named.
Branches of Chemistry
• Many major areas of study for Many major areas of study for specializationspecialization
• Several career opportunitiesSeveral career opportunities
• Also used in many other jobsAlso used in many other jobs
1. Organic Chemistry
• Organic is the study of Organic is the study of matter that contains ______matter that contains ______
• Organic chemists study the Organic chemists study the structure, function, structure, function, synthesis, and identity of synthesis, and identity of carbon compoundscarbon compounds
• Useful in petroleum Useful in petroleum industry, pharmaceuticals, industry, pharmaceuticals, polymerspolymers
2. Inorganic Chemistry
• Inorganic is the Inorganic is the study of matter that study of matter that does NOT contain does NOT contain ________________
• Inorganic chemists Inorganic chemists study the structure, study the structure, function, synthesis, function, synthesis, and identity of non-and identity of non-carbon compoundscarbon compounds
• Polymers, Polymers, MetallurgyMetallurgy
3. Biochemistry
• Biochemistry is Biochemistry is the study of the study of chemistry in chemistry in ______ things______ things
• Cross between Cross between biology and biology and chemistrychemistry
• Pharmaceuticals Pharmaceuticals and geneticsand genetics
4. Physical Chemistry
• Physical Physical chemistry is the chemistry is the physics of physics of chemistry… the chemistry… the forces of matterforces of matter
• Much of p-chem Much of p-chem is computationalis computational
• Develop Develop theoretical ideas theoretical ideas for new for new compoundscompounds
HONK if you passed p-chem
5. Analytical Chemistry
• Analytical Analytical chemistry is the chemistry is the study of high study of high precision precision measurementmeasurement
• Find composition Find composition and identity of and identity of chemicalschemicals
• Forensics, quality Forensics, quality control, medical control, medical teststests
Types of Observations and Types of Observations and MeasurementsMeasurements
•We makeWe make QUALITATIVEQUALITATIVE observations of reactions — observations of reactions — changes in color and changes in color and physical state.physical state.
•We also makeWe also make QUANTITATIVE QUANTITATIVE MEASUREMENTSMEASUREMENTS, which involve , which involve numbersnumbers..–UseUse SI unitsSI units — based on — based on the metric system, rather the metric system, rather than the US customary than the US customary system. system.
SI measurementSI measurement• Le Système international d'unitésLe Système international d'unités
(system international).
• The only countries that have not The only countries that have not officiallyofficially adopted SI are Liberia (in adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are Burma, in SE Asia), but now these are reportedly using metric regularlyreportedly using metric regularly
• Metrication is a process that does not Metrication is a process that does not happen all at once, but is rather a happen all at once, but is rather a process that happens over time. process that happens over time.
• Among countries with non-metric Among countries with non-metric usage, the U.S. is the usage, the U.S. is the only country only country significantly holding outsignificantly holding out.. The U.S. The U.S. officially adopted SI in 1866.officially adopted SI in 1866.
Information from U.S. Metric Association
Chemistry In ActionChemistry In Action
On 9/23/99, $125,000,000 Mars Climate Orbiter entered Mar’s atmosphere 100 km lower than planned and was destroyed by heat.
1 lb = 1 N
1 lb = 4.45 N
“This is going to be the cautionary tale that will be embedded into introduction to the metric system in elementary school, high school, and college science courses till the end of time.”
Standards of MeasurementStandards of Measurement
When we measure, we use a measuring tool to When we measure, we use a measuring tool to compare some dimension of an object to a standard.compare some dimension of an object to a standard.
For example, at one time the For example, at one time the standard for length was the standard for length was the king’s foot. What are some king’s foot. What are some
problems with this standard?problems with this standard?
Stating a MeasurementStating a Measurement
In every measurement there is aIn every measurement there is a
Number Number followed by a followed by a
Unit Unit from a measuring devicefrom a measuring device
The number should also be as precise as the measurement!The number should also be as precise as the measurement!
UNITS OF MEASUREMENTUNITS OF MEASUREMENT
Use SI units (Use SI units (base unitsbase units) — ) — based on the metric systembased on the metric system
Length Length
MassMass
VolumeVolume
TimeTime
TemperatureTemperature
______________________________
Kilogram, kgKilogram, kg
Seconds, sSeconds, s
Celsius degrees, ˚CCelsius degrees, ˚Ckelvins, Kkelvins, K
______________________________
Mass vs. WeightMass vs. Weight
• Mass: Amount of Mass: Amount of Matter (grams, Matter (grams, measured with a measured with a BALANCE)BALANCE)
• Weight: Force Weight: Force exerted by the exerted by the mass, only present mass, only present with gravity with gravity (pounds, measured (pounds, measured with a SCALE)with a SCALE)
• Note: mass and Note: mass and weight terms usage!weight terms usage!
Can you hear Can you hear me now?me now?
Some Tools for MeasurementSome Tools for Measurement
Which tool(s) Which tool(s) would you use to would you use to measure:measure:
A.A. temperature temperature
B.B. volume volume
C.C. time time
D.D. weight weight
Learning Check
Match Match L) lengthL) length M) mass M) mass V) volume V) volume
____ A. A bag of tomatoes is 4.6 kg.____ A. A bag of tomatoes is 4.6 kg.
____ B. A person is 2.0 m tall.____ B. A person is 2.0 m tall.
____ C. A medication contains 0.50 g Aspirin.____ C. A medication contains 0.50 g Aspirin.
____ D. A bottle contains 1.5 L of water.____ D. A bottle contains 1.5 L of water.
M
L
M
V
Learning CheckLearning Check
What are some U.S. units that are used to What are some U.S. units that are used to measure each of the following?measure each of the following?
A. length A. length
B. volume B. volume
C. weightC. weight
D. temperatureD. temperature
SolutionSolution
Some possible answers areSome possible answers are
A.A. length length inch, foot, yard, mile inch, foot, yard, mile
B.B. volumevolume cup, teaspoon, gallon, pint, quartcup, teaspoon, gallon, pint, quart
C.C. weight weight ounce, pound (lb), tonounce, pound (lb), ton
D.D. temperature temperature FF
Metric Metric PrefixesPrefixes• Kilo-Kilo- means 1000 of that unit means 1000 of that unit
– 1 kilometer (km) = 1000 meters (m)1 kilometer (km) = 1000 meters (m)
• Centi-Centi- means 1/100 of that unit means 1/100 of that unit
– 1 meter (m) = 100 centimeters (cm)1 meter (m) = 100 centimeters (cm)
– 1 dollar = 100 cents1 dollar = 100 cents
• Milli-Milli- means 1/1000 of that unit means 1/1000 of that unit
– 1 Liter (L) = 1000 milliliters (mL)1 Liter (L) = 1000 milliliters (mL)
Units of Units of LengthLength
• ? kilometer (km) = 500 meters (m)? kilometer (km) = 500 meters (m)
• 2.5 meter (m) = ? centimeters (cm)2.5 meter (m) = ? centimeters (cm)
• 1 centimeter (cm) = ? millimeter (mm)1 centimeter (cm) = ? millimeter (mm)
• 1 nanometer (nm) = 1.0 x 101 nanometer (nm) = 1.0 x 10-9-9 meter meter
O—H distance =O—H distance =9.4 x 109.4 x 10-11 -11 mm9.4 x 109.4 x 10-9 -9 cmcm0.094 nm0.094 nm
O—H distance =O—H distance =9.4 x 109.4 x 10-11 -11 mm9.4 x 109.4 x 10-9 -9 cmcm0.094 nm0.094 nm
Learning Check
Select the unit you would use to measure Select the unit you would use to measure
1. Your height1. Your height
a) millimeters a) millimeters b) metersb) meters c) kilometers c) kilometers
2. Your mass2. Your mass
a) milligramsa) milligrams b) gramsb) grams c) kilograms c) kilograms
3. The distance between two cities3. The distance between two cities
a) millimetersa) millimeters b) metersb) meters c) kilometers c) kilometers
4. The width of an artery4. The width of an arterya) millimetersa) millimeters b) metersb) meters c) kilometers c) kilometers
Solution
1. Your height1. Your height
b) metersb) meters
2. Your mass2. Your mass
c) kilogramsc) kilograms
3. The distance between two cities3. The distance between two cities
c) kilometersc) kilometers
4. The width of an artery4. The width of an arterya) millimetersa) millimeters
Equalities
State the same measurement in two different State the same measurement in two different unitsunits
lengthlength
10.0 in.10.0 in.
25.4 cm25.4 cm
1. 1000 m = 1 1. 1000 m = 1 ______ a) mm b) km c) dma) mm b) km c) dm
2. 0.001 g = 1 2. 0.001 g = 1 ___ ___ a) mg b) kg c) dga) mg b) kg c) dg
3. 0.1 L = 1 3. 0.1 L = 1 ______ a) mL b) cL c) dLa) mL b) cL c) dL
4. 0.01 m = 1 ___ 4. 0.01 m = 1 ___ a) mm b) cm c) dma) mm b) cm c) dm
Learning Check
Conversion FactorsConversion Factors
Fractions in which the numerator and Fractions in which the numerator and denominator are EQUAL quantities expressed denominator are EQUAL quantities expressed in different unitsin different units
Example: 1 in. = 2.54 cm
Factors: 1 in. and 2.54 cm
2.54 cm 1 in.
Conversions
• Converting to a smaller unit, multiply to get a bigger number.
- E.g. 1.85 m to cm.
- 1.85mX100cm=185cm
- LARGER UNITmultiply=>SMALLER UNIT
• Converting to a larger unit, divide to get a smaller number.
- E.g. 150 cm to m = 150/100= 1.5 m
- SMALLER UNITdivide => LARGER UNIT
Learning Check
Write conversion factors that relate each of Write conversion factors that relate each of the following pairs of units:the following pairs of units:
1. Liters and mL1. Liters and mL
2. Hours and minutes2. Hours and minutes
3. Meters and kilometers3. Meters and kilometers
How many minutes are in 2.5 hours?
Conversion factor
2.5 hr x 2.5 hr x 60 min 60 min = 150 min = 150 min
1 hr1 hr
cancel
By using dimensional analysis / factor-label method, By using dimensional analysis / factor-label method, the UNITS ensure that you have the conversion right the UNITS ensure that you have the conversion right side up, and the UNITS are calculated as well as the side up, and the UNITS are calculated as well as the
numbers!numbers!
Sample Problem
• You have $7.25 in your pocket in You have $7.25 in your pocket in quarters. How many quarters do you quarters. How many quarters do you have?have?
7.25 dollars 4 quarters7.25 dollars 4 quarters
1 dollar1 dollar X = 29 quarters= 29 quarters
Learning Check
A rattlesnake is 2.44 m long. How A rattlesnake is 2.44 m long. How long is the snake in cm?long is the snake in cm?
a) a) 2440 cm2440 cm
b)b) 244 cm244 cm
c)c) 24.4 cm24.4 cm
Learning Check
How many seconds are in 1.4 days?
Unit plan: days hr min seconds
1.4 days x 24 hr x ?? 1 day
Solution
Unit plan: days hr min seconds
1.4 day x 24 hr x 60 min x 60 sec
1 day 1 hr 1 min
= 1.2 x 105 sec
Wait a minute!
What is What is wrongwrong with the following setup? with the following setup?
1.4 day x 1.4 day x 1 day 1 day x x 60 min 60 min x x 60 sec 60 sec
24 hr 1 hr 1 min24 hr 1 hr 1 min
CONVERSIONS PRACTICE1.Write 550 millimeters as meters.2.Write 3.5 seconds as milliseconds.3.Convert 1.6 kilograms to grams.4.Convert 2500 milligrams to
kilograms.5.Convert 4 centimeters to micrometers.6.Change 2800 millimoles to moles.
7.Change 6.1 amperes to milliamperes
English and Metric English and Metric ConversionsConversions
• If you know ONE conversion for If you know ONE conversion for each type of measurement, you each type of measurement, you can convert anything!can convert anything!
• You must You must memorizememorize and use these and use these conversions:conversions:
–Mass: 454 grams = 1 poundMass: 454 grams = 1 pound
–Length: 2.54 cm = 1 inchLength: 2.54 cm = 1 inch
–Volume: 0.946 L = 1 quartVolume: 0.946 L = 1 quart
Learning CheckLearning Check
An adult human has 4.65 L of blood. How An adult human has 4.65 L of blood. How many gallons of blood is that?many gallons of blood is that?
Unit plan: L qt gallon
Equalities: 1 quart = 0.946 L
1 gallon = 4 quarts
Your Setup:
Steps to Problem SolvingSteps to Problem Solving
Read problemRead problem Identify data Identify data Make a unit plan from the initial unit to the Make a unit plan from the initial unit to the
desired unitdesired unit Select conversion factorsSelect conversion factors Change initial unit to desired unitChange initial unit to desired unit Cancel units and checkCancel units and check Do math on calculator Do math on calculator Give an answer using significant figuresGive an answer using significant figures
Temperature ScalesTemperature Scales•FahrenheitFahrenheit•CelsiusCelsius•KelvinKelvin
Anders Celsius1701-1744
Lord Kelvin(William Thomson)1824-1907
Temperature ScalesTemperature Scales
Notice that 1 kelvin = 1 degree Celsius1 kelvin = 1 degree Celsius
Boiling Boiling point of point of waterwater
Freezing Freezing point of point of waterwater
CelsiusCelsius
100 ˚C100 ˚C
0 ˚C0 ˚C
100˚C100˚C
KelvinKelvin
373 K373 K
273 K273 K
100 K100 K
FahrenheitFahrenheit
32 ˚F32 ˚F
212 ˚F212 ˚F
180˚F180˚F
Calculations Calculations Using Using TemperatureTemperature
Science uses temp in Science uses temp in kelvin, because it kelvin, because it
does not give a negative or zero does not give a negative or zero
value.value.
•T (K) = t (˚C) + 273.15T (K) = t (˚C) + 273.15• Body temp = 37 ˚C + 273 = 310 KBody temp = 37 ˚C + 273 = 310 K
• Liquid nitrogen = -196 ˚C + 273 = 77 KLiquid nitrogen = -196 ˚C + 273 = 77 K
Science uses temp in Science uses temp in kelvin, because it kelvin, because it
does not give a negative or zero does not give a negative or zero
value.value.
•T (K) = t (˚C) + 273.15T (K) = t (˚C) + 273.15• Body temp = 37 ˚C + 273 = 310 KBody temp = 37 ˚C + 273 = 310 K
• Liquid nitrogen = -196 ˚C + 273 = 77 KLiquid nitrogen = -196 ˚C + 273 = 77 K
Fahrenheit FormulaFahrenheit Formula
180°F180°F = = 9°F 9°F == 1.8°F 1.8°F 100°C 100°C 5°C 5°C 1°C1°C
Zero point: 0°C = 32°FZero point: 0°C = 32°F
°F = 9/5 °C + 32°F = 9/5 °C + 32
Celsius FormulaCelsius Formula
Rearrange to find T°CRearrange to find T°C
°F °F = = 9/5 °C + 329/5 °C + 32
°F - 32 = °F - 32 = 9/5 °C ( +32 - 32)9/5 °C ( +32 - 32)
°F - 32°F - 32 = = 9/5 °C9/5 °C
9/5 9/5 9/5 9/5
(°F - 32) * 5/9 = (°F - 32) * 5/9 = °C°C
Temperature ConversionsTemperature Conversions
A person with hypothermia has a body A person with hypothermia has a body temperature of 29.1°C. What is the body temperature of 29.1°C. What is the body temperature in °F? temperature in °F?
°F °F = = 9/5 (29.1°C) + 329/5 (29.1°C) + 32
= = 52.4 + 3252.4 + 32
= = 84.4°F84.4°F
Learning CheckLearning Check
The normal temperature of a chickadee is The normal temperature of a chickadee is 105.8°F. What is that temperature in °C?105.8°F. What is that temperature in °C?
1) 73.8 °C 1) 73.8 °C
2) 58.8 °C2) 58.8 °C
3) 41.0 °C3) 41.0 °C
Learning Check
Pizza is baked at 455°F. What is that in °C?
1) 437 °C1) 437 °C
2) 235°C2) 235°C
3) 221°C3) 221°C
What is Scientific Notation?What is Scientific Notation?
• Scientific notation is a way of Scientific notation is a way of expressing really big numbers or expressing really big numbers or really small numbers.really small numbers.
• It is most often used in It is most often used in “scientific” calculations where the “scientific” calculations where the analysis must be very precise.analysis must be very precise.
• For very large and very small For very large and very small numbers, scientific notation is numbers, scientific notation is more concise.more concise.
Scientific notation Scientific notation consists of two parts:consists of two parts:
• A number between 1 and 10A number between 1 and 10
• A power of 10A power of 10
N x 10N x 10xx
Are the following in scientific notation?
To change standard form To change standard form to scientific notation…to scientific notation…
• Place the decimal point so that there is Place the decimal point so that there is one non-zero digit to the left of the one non-zero digit to the left of the decimal point.decimal point.
• Count the number of decimal places Count the number of decimal places the decimal point has “moved” from the decimal point has “moved” from the original number. This will be the the original number. This will be the exponent on the 10.exponent on the 10.
• If the original number was less than 1, If the original number was less than 1, then the exponent is negative. If the then the exponent is negative. If the original number was greater than 1, original number was greater than 1, then the exponent is positive.then the exponent is positive.
ExamplesExamples
• Given: 289,800,000Given: 289,800,000
• Use: 2.898 (moved 8 places)Use: 2.898 (moved 8 places)
• Answer:Answer: 2.898 x 102.898 x 1088
• Given: 0.000567Given: 0.000567
• Use: 5.67 (moved 4 places)Use: 5.67 (moved 4 places)
• Answer:Answer: 5.67 x 105.67 x 10-4-4
To change scientific To change scientific notation to standard notation to standard
form…form…• Simply move the decimal point to Simply move the decimal point to
the right for positive exponent 10. the right for positive exponent 10.
• Move the decimal point to the left Move the decimal point to the left for negative exponent 10.for negative exponent 10.
(Use zeros to fill in places.)(Use zeros to fill in places.)
ExampleExample
• Given: 5.093 x 10Given: 5.093 x 1066
• Answer: Answer: 5,093,0005,093,000 (moved 6 places (moved 6 places to the right)to the right)
• Given: 1.976 x 10Given: 1.976 x 10-4-4
• Answer: Answer: 0.00019760.0001976 (moved 4 places (moved 4 places to the left)to the left)
Learning Check
• Express these numbers in Express these numbers in Scientific Notation:Scientific Notation:
1)1) 405789405789
2)2) 0.0038720.003872
3)3) 30000000003000000000
4)4) 22
5)5) 0.4782600.478260
Three Three targets with targets with three arrows three arrows each to each to shoot.shoot.
Can you hit the bull's-eye?Can you hit the bull's-eye?
Both accurate and precise
Precise but not accurate
Neither accurate nor precise
How do How do they they compare?compare?
Can you define accuracy and precision?Can you define accuracy and precision?
DENSITYDENSITY - an important - an important and useful physical propertyand useful physical property
Density = mass(g) volume(cm3)
Density = mass(g) volume(cm3)
Mercury
13.6 g/cm13.6 g/cm33 21.5 g/cm21.5 g/cm33
Aluminum
2.7 g/cm2.7 g/cm33
Platinum
ProblemProblem A piece of copper has a mass A piece of copper has a mass of 57.54 g. It is 9.36 cm long, 7.23 cm of 57.54 g. It is 9.36 cm long, 7.23 cm wide, and 0.95 mm thick. Calculate wide, and 0.95 mm thick. Calculate density (g/cmdensity (g/cm33).).
Density = mass(g) volume(cm3)
Density = mass(g) volume(cm3)
StrategyStrategy1. Get dimensions in common units.1. Get dimensions in common units.
2.2. Calculate volume in cubic centimeters. Calculate volume in cubic centimeters.
3. Calculate the density.3. Calculate the density.
SOLUTIONSOLUTION
1. Get dimensions in common units.1. Get dimensions in common units.
2.2. Calculate volume in cubic centimeters. Calculate volume in cubic centimeters.
3. Calculate the density.3. Calculate the density.
0.95 mm • 1cm
10 mm = 0.095 cm
57.54 g
6.4 cm3 = 9.0 g / cm3
(9.36 cm)(7.23 cm)(0.095 cm) = 6.4 cm(9.36 cm)(7.23 cm)(0.095 cm) = 6.4 cm33
Note only 2 significant figures in the answer!Note only 2 significant figures in the answer!
PROBLEM: Mercury (Hg) has a density PROBLEM: Mercury (Hg) has a density of 13.6 g/cmof 13.6 g/cm33. What is the mass of 95 mL . What is the mass of 95 mL of Hg in grams? In pounds?of Hg in grams? In pounds?
PROBLEM: Mercury (Hg) has a density PROBLEM: Mercury (Hg) has a density of 13.6 g/cmof 13.6 g/cm33. What is the mass of 95 mL . What is the mass of 95 mL of Hg in grams? In pounds?of Hg in grams? In pounds?
Solve the problem usingSolve the problem using DIMENSIONAL DIMENSIONAL ANALYSIS.ANALYSIS.
StrategyStrategy
1.1. Use density to calc. mass (g) from Use density to calc. mass (g) from volume.volume.
2.2. Convert mass (g) to mass (lb)Convert mass (g) to mass (lb)
Need to know conversion factorNeed to know conversion factor
= 454 g / 1 lb= 454 g / 1 lb
PROBLEM: Mercury (Hg) has a density of PROBLEM: Mercury (Hg) has a density of 13.6 g/cm13.6 g/cm33. What is the mass of 95 mL of Hg?. What is the mass of 95 mL of Hg?PROBLEM: Mercury (Hg) has a density of PROBLEM: Mercury (Hg) has a density of 13.6 g/cm13.6 g/cm33. What is the mass of 95 mL of Hg?. What is the mass of 95 mL of Hg?
First, note thatFirst, note that 1 cm1 cm33 = 1 mL = 1 mL
1.1. Convert volume to massConvert volume to mass
PROBLEM: Mercury (Hg) has a density of 13.6 PROBLEM: Mercury (Hg) has a density of 13.6 g/cmg/cm33. What is the mass of 95 mL of Hg?. What is the mass of 95 mL of Hg?PROBLEM: Mercury (Hg) has a density of 13.6 PROBLEM: Mercury (Hg) has a density of 13.6 g/cmg/cm33. What is the mass of 95 mL of Hg?. What is the mass of 95 mL of Hg?
95 cm3 • 13.6 g
cm3 = 1.3 x 103 g
1.3 x 103 g • 1 lb
454 g = 2.8 lb
2.2. Convert mass (g) to mass (lb)Convert mass (g) to mass (lb)
Learning CheckLearning Check
Osmium is a very dense metal. What is its Osmium is a very dense metal. What is its
density in g/cmdensity in g/cm3 3 if 50.00 g of the metal occupiesif 50.00 g of the metal occupies
a volume of 2.22cma volume of 2.22cm33??
1) 2.25 g/cm1) 2.25 g/cm33
2)2) 22.5 g/cm22.5 g/cm33
3)3) 111 g/cm111 g/cm33
Solution
2) Placing the mass and volume of the osmium 2) Placing the mass and volume of the osmium metal into the density setup, we obtainmetal into the density setup, we obtain
D = D = massmass = = 50.00 g 50.00 g = = volumevolume2.22 cm2.22 cm33
= 22.522522 g/cm= 22.522522 g/cm3 3 == 22.5 g/cm22.5 g/cm33
Volume DisplacementVolume Displacement
A solid displaces a matching volume of A solid displaces a matching volume of water when the solid is placed in water.water when the solid is placed in water.
33 mL33 mL25 mL 25 mL
Learning CheckLearning Check
What is the density (g/cmWhat is the density (g/cm33) of 48 g of a metal if ) of 48 g of a metal if the metal raises the level of water in a graduated the metal raises the level of water in a graduated cylinder from 25 mL to 33 mL? cylinder from 25 mL to 33 mL?
1) 0.2 g/ cm1) 0.2 g/ cm33 2) 6 g/m 2) 6 g/m33 3) 252 g/cm3) 252 g/cm33
33 mL33 mL
25 mL25 mL
Learning CheckLearning Check
Which diagram represents the liquid layers in the Which diagram represents the liquid layers in the cylinder?cylinder?
(K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 (K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL)g/mL,) (W) water (1.0 g/mL)
1)1) 2) 2) 3) 3)
K
K
W
W
W
V
V
V
K
SolutionSolution
(K) Karo syrup (1.4 g/mL), (V) vegetable oil (K) Karo syrup (1.4 g/mL), (V) vegetable oil (0.91 g/mL,) (W) water (1.0 g/mL)(0.91 g/mL,) (W) water (1.0 g/mL)
1)1)
K
W
V
Learning CheckLearning Check
The density of octane, a component of The density of octane, a component of gasoline, is 0.702 g/mL. What is the gasoline, is 0.702 g/mL. What is the mass, in kg, of 875 mL of octane?mass, in kg, of 875 mL of octane?
1) 0.614 kg1) 0.614 kg
2) 614 kg2) 614 kg
3) 1.25 kg3) 1.25 kg
Learning CheckLearning Check
If blood has a density of 1.05 g/mL, how If blood has a density of 1.05 g/mL, how many liters of blood are donated if 575 g many liters of blood are donated if 575 g of blood are given?of blood are given?
1) 1) 0.548 L0.548 L
2) 2) 1.25 L1.25 L
3) 3) 1.83 L1.83 L
Scientific Method
1.1. State the problem clearly.State the problem clearly.2.2. Gather information.Gather information.3.3. Form a hypothesis.Form a hypothesis.4.4. Test the hypothesis.Test the hypothesis.5.5. Evaluate the data to form a conclusion.Evaluate the data to form a conclusion.
If the conclusion is valid, then it becomes a If the conclusion is valid, then it becomes a theorytheory. If the theory is found to be true over . If the theory is found to be true over along period of time (usually 20+ years) with along period of time (usually 20+ years) with no counter examples, it may be considered a no counter examples, it may be considered a lawlaw..
6. Share the results.6. Share the results.
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