Chapter 3 Study Guide
STP- Pressure= 1 ATM
Temp= 0 degrees Celcius , or 273 degrees Kelvin
R= Constant= .0821 atm/mol or 8.3145 j/mol
Sublimation
Melt.
Boil
Solid. Liquid.
Gas
Freezing. Condense
Deposition
Solid-closely packed vibrating particles
Definite shape and volume
Liquid- more energy; further apart
Compressible
Definite shape
No definite volume
Gas- highest energy; furthest apart
Highly compressible
No shape or volume
What's between air molecules? Answer: NOTHING.
Physical Properties- Observe property without changing atom or molecules
-Color, texture, BP, MP, solubility
Chemical Properties- How substance reacts
-Flammability, reactivity with oxygen, acid, or base, corrosiveness
Intensive Properties- Don't change no matter what size
- Color, density
Extensive Properties- Changes when size or substance changes
- Mass, volume
Density
Ex) A rock has a mass of 6.37 grams. What is its density if its volume is 8.21 mL???
D=M/V
D= 6.37/8.21 = .776 g/mL
Ex) A sample of a liquid has a density of 1.75 g/cm^3. What is the mass of 35.5 cm^3 of
this metal.
1.75 g/mL = M/ 35.5
35.5 x 1.75 = M
M= 62.1
Physical Changes- do not affect structure- only properties- Melting point, freezing point, boiling point
Chemical Changes- Changes how elements of molecules are arranged
- When salt is dissolved and separated back out
- Fire!
- Rusting
Ex) What is the mass of a piece of flesh from Mrs. Yard if it has a density of 42.25 grams
and a density of 3.80 g/mL???
3.50 = 42.25 / V
V= 12.9
What is the difference between melting and dissolving?
Answer: Melting is a phase changes from the solid state into the liquid state of a
substance. Dissolving refers to the addition of a solute into a solution and having the
solute completely “disappear” or dissociate.
Pressure:
Mole increase= Pressure increase
Temperature increase= Pressure increase
Volume decrease= pressure increase
Kinetic Molecular Theory (KMT)
 Matter is made up of particles that contain a certain mass
 The distance separating gas molecules is so big that the size of the molecules of
gas is insignificant
 Gas particles move constantly, fast, and randomly
 No kinetic energy is lost during collisions
 Temperature is directly proportional to kinetic energy
 Particles exert no force on each other (neither attract nor repel)
However, real gases do deviate from KMT. They are not perfectly elastic; they can exert
forces on each other. A gas is most ideal at a low pressure and high temperature.
Diffusion- Spread of particles into a bigger space
-Ex) Producing H₂S in the classroom. And crying while it diffuses into your nostrils.
Effusion- Escape of particles through tiny holes
-Ex) Balloons deflating over periods of time
Avagadro- Molecules are too many to count, so Avagadro discovered the “mole”, no not
the one that lives underground, the kind of SCIENCE. A mole is 6.02 x 1023 molecules.
Ex) How many molecules of water in 10 grams?
10 g
1 mol
6.02 x 1023 = 3.346 x 1023 molecules
18.02g/mol 1 mol
Find the molecular mass:
CaCl2
Ca= 40.08 g/mol
Cl= 2 x 35.45 g/mol
CaCl2 = 110.98 g/mol Can convert this into grams if given moles….. Ex) How many
grams in 10 moles?
10 mol= 110.98/1 mol = 1109.8
grams!
Pressure Conversions
1 atm=760 Torr= 760 mm Hg= 101.3 kPa
Avagadro’s Law
P1/n1=P2/n2 (n=moles)
Charles’ Law
Combined
V1/T1=V2/T2
P1V1/n1T1=P2V2/n2T2`
Boyle’s Law
P1V1=P2V2
Ideal Gas Law
PV=nRT
R-Constant given
This equation can happen at any temperature or pressure. Plug in all values given and
solve for missing piece. If finding n, moles, you can then convert to grams or molecules if
needed.