Introduction
Chemistry:The study of matter and its changes
Chemistry investigates and explains the sub-microscopic reasons for the what happens in the macroscopic world!
Introduction
Sub-microscopic understanding leads to understanding of the world around you:
How does bleach remove stains?
What causes and air bag to inflate?
Why does DNA have a double helical structure?
What makes a rose smell sweet and old fish smell awful?
Introduction
How does radio-carbon dating tell how old a fossil is?
What are electrolytes and why do sports drinks like Gatorade contain them?
What happens to garbage in a landfill? Is it always better to use biodegradable materials?
Introduction
Why should YOU study chemistry?
PsychologyEnglishBSW/MSWFine ArtsPre-Law
Required for your college major
Pre-medPre-pharmacyPre-dentalBiologyGeologyEnvironmental ScienceEngineeringNursing
IntroductionChemistry is the foundation of other sciences
Physics Biology Geology Astronomy
Chemistry impacts our daily lives! Food, clothing and shelter Health care Environment Life itself
Measurement
Metric System
s second Time
K or o C Kelvin or
degree celsiusTemperature
Lliter Volume
g gram Mass
m meterLength
Unit Symbol UnitQuantity
Prefixes
ExampleMeans..SymbolPrefix
cghundredthc centi-
gmillionthmicro-
kmthousandkkilo-
mLthousandthmmilli-
every student should know…
More prefixes…
GAGgiga-
MLmillionmega- M
couldn’t hurt to know these ones, too:
thousand million
ExampleMeans..SymbolPrefix
Benefits of the Metric System:
• Uses Decimal System• International Standard• The units relate to
each other by using water as standard!
(What does that mean?)
“the units relate to each other…
1cm3 = 1 mL
therefore , (10cm)3 = 1 L
1000 cm3 = 1 L
http://www.metricamerica.com
…by using water as a standard”:
1 kg H2O ≈ 1 L H2O ≈ (10 cm)3 H2O ≈ 1000 cm3 H2O
http://www.metricamerica.com/images/Export00_288.mov
1g H2O ≈ 1 mL H2O
Volume is special
because:
• Volume can be measured in
liters (L),
milliliters (mL), etc. s
or…
OR…
• Volume can be measured in
cubic meters (m3)
centimeters (cm3),
…..etc.
Remember;
1 cm1 cm3 3 = 1 mL = 1 mL
Remember any geometry?• Volume of a cube is ….
l x w x hi.e. 4cm x 5cm x 2cm = 40 cm3
i.e. x (5cm)2 x 10cm = 250 cm3
•Volume of a cylinder is ….
r2 h
Typically,
mL or L are used to describe the volume of a liquid...
…and cm3 or m3 are used to describe the volume of a regularly shaped solid.
Volume of a Rock…To find the volume of objects with weird shapes,
use a technique called “water displacement”
in this case,the volume of the solid may be in
cm3 or mLRemember:
1 cm1 cm3 3 = 1 mL = 1 mL
Determining the Volume of an Irregularly Shaped Solid
22 mL 32 mL
Temperature is special because…
We will sometimes use degrees celsius…
…we sometimes will use kelvin.
Absolute Zero
Freezing Point of Water
Body Temperature
Boiling Point of Water
-459 O
32 O
98 O
212 O
F
-273 o
0 O
37 O
100 O
C
0
273
310
373
KExample
Meters, Liters, Grams, Seconds….
These are units you should be familiar with.
In chemistry,we will use math to do weird things to these nice units…
…and turn them into units that are complex.
Complex units like….
g/mL and kg•m/s2
Math with Units…
5 • 5 = 25
3m • 4m =
4 kg • 2 m/s2 =
10 L•atm ÷ 2 mol•K = 5(L•atm)/(mol•K)
8 kg•m/s2
12 m2
Examples:
12m2 ÷ 12m = 1m
Example: DensityDensity is a property of matter. If you measure the mass and the volume of an object, you can calculate it’s density using the formula:
(g) (mL)
D = m/v
Density = mass/volumeSo, the units of density must be…. g/mL
Complex Units come from a formula…
• Why is density measured in g/mL?
Because the formula for density is
(aka “grams per milliliter”) (not “gee slash em-ell”)
m mass (in grams) g
D = ----- = ------------ -------------- ----
v volume (in milliliters) mL
DENSITYDENSITYStyrofoamStyrofoam BrickBrick
Brick is more dense than Styrofoam because there is
more mass
packed into the
same volume
(more molecules or atoms in the same space.)
Substance Density (g/mL)
• Air 0.0013 g/mL
• Wood (Oak) 0.80 g/mL
• Steel 7.80 g/mL
•Water 1.00 g/mL
Density of Gold:
19.30 g/mL
Silver:
10.50 g/mL
Aluminum: 2.70 g/mL
Atoms of some elements are more dense Atoms of some elements are more dense than others. than others.
DENSITY - an important and useful physical property
Density mass (g)volume (cm3)
Density mass (g)volume (cm3)
13.6 g/cm13.6 g/cm33 21.5 g/cm21.5 g/cm33
Aluminum
2.7 g/cm2.7 g/cm33
PlatinumMercury
Variations of the Density Formula:
D = m/v
v = m/D
m = v • D
D v
m
Application:
Calculate the density of a 57.9g sample of metal with a volume of 22.45mL.
Application:
• Calculate the mass of 4,800 mL of molten lead (density = 11.4g/mL)?
•What is the mass in kg?
Application:
• A camelbak backpack hold 1 kg of water. What is the volume of the backpack?
Application:
• Molten iron (Fe) has a known density of 7.87 g/cm3. What would be the volume of 595 kg of molten iron, in liters?
Metric System
s second Time
K or o C Kelvin or
degree celsiusTemperature
Lliter Volume
g gram Mass
m meterLength
Unit Symbol UnitQuantity
Prefixes
ExampleMeans..SymbolPrefix
cghundredthc centi-
gmillionthmicro-
kmthousandkkilo-
mLthousandthmmilli-
every student should know…
Typically,
mL or L are used to describe the volume of a liquid...
…and cm3 or m3 are used to describe the volume of a regularly shaped solid.
Temperature is special because…
We will sometimes use degrees celsius…
…we sometimes will use kelvin.
Absolute Zero
Freezing Point of Water
Body Temperature
Boiling Point of Water
-459 O
32 O
98 O
212 O
F
-273 o
0 O
37 O
100 O
C
0
273
310
373
KExample
Example: DensityDensity is a property of matter. If you measure the mass and the volume of an object, you can calculate it’s density using the formula:
(g) (mL)
D = m/v
Density = mass/volumeSo, the units of density must be…. g/mL