Chem test 2

Question 1

What is the kinetic theory of matter?

Answer 1

• a prediction of how matter should behave
• all matter is made up of moving particles (molecules or atoms)
• phase changes occur with increases in kinetic energy in matter (typically from heat)

Question 2

What are the characteristics of gasses?

Answer 2

• physical properties of gasses are all similar
• composed mainly of nonmetallic elements with simple formulas and low molar masses
• unlike liquids and solids, gasses:
  1. expand to fill their containers
  2. are highly compressible
  3. have extrememly low densities
• two or more gasses form a homogeneous mixture
• molecules move independently with no forces keeping them together or pushing them apart

Question 3

What is Avagadros number?

Answer 3

6.022 X10²³ = 1mol

Question 4

kinetic theory of gases:

Answer 4

• Gases consist of a large number of molecules in continuous random motion (Avagadros #)
• the combined volume of all molecules of the gas is negligible relative to the total volume in which the gas is contained
• attractive and repulsive forces between gas molecules are weak (d/t distance)
• energy can be transfered between molecules during collisions, but the avg. kinetic energy of the molecules does not change with time, as long as the temperature of the gas remains constant (like a bouncy ball)
• Avg. kinetic energy of gas molecules is only dependent on temperature

Question 5

Root mean squared velocity is what?

Answer 5

the speed that is directly associated with the average kinetic energy of the gas molecules

Question 6

if a gas has a low molar mass, its speed will be ______ than one with a higher molar mass

Answer 6

greater

Question 7

how to solve for kelvin

Answer 7

C + 273.15

Question 8

define atmospheric pressure

Answer 8

the weight of air per unit of area
wt. of air/ area

Question 9

define pressure

Answer 9

the amount of force applied to an area
force/area

Question 10

what is Boyle’s law?

Answer 10

the pressure of a gas is inversely related to it’s volume when temperature is constant

P₁V₁=P₂V₂

Question 11

what is Charle’s law?

Answer 11

The temperature of a gas is directly related to volume
V₁/T₁ = V₂/T₂

Question 12

What is Gay-Lussac’s law?

Answer 12

the pressure exerted by gas is directly related to the temperature of the gas
P₁/T₁ = P₂/T₂

Question 13

What is the combined gas law?

Answer 13

The combination of Boyles, Charles, and Gay-Lussac’s laws where n (number of moles) are constant

Question 14

What is avogadros law?

Answer 14

the volume of a gas is directly related to the amount(number of moles) of the gas.
Temperature and pressure are constant

V₁/n₁ = V₂/n₂

Question 15

What is the ideal gas law?

Answer 15

pV=nRT

Question 16

What is Dalton’s law?

Answer 16

if two gases that do not react are combined in a container, they act as if they are along in the container. The total pressure of a mixture equals the sum of the pressures that each would exert as if they were alone
P_total= P₁+P₂+₃….. etc

Question 17

What is effusion?

Answer 17

the escape of gas molecules through a tiny hole into an evacuated space

Question 18

What is diffusion?

Answer 18

the spread of one substance throughout a space or a second substance (from high to low concentration)

Question 19

What is grahams law?

Answer 19

relates the molar mass of two gases to their rate of speed of travel

the lower the molar mass the faster the rate of speed

Question 20

What is Henry’s law?

Answer 20

the solubility of a gas in a given volume of a liquid is directly proportional to the partial pressure of that gas in equilibrium with that of the liquid

increased temp=gas is less soluble in liquid

Question 21

in the real world, the behavior of gases conforms to the ideal gas law only at

Answer 21

relatively high temperature or low pressure

Question 22

What kind of adjustments can be made to the ideal gas law to take into account deviation from ideal behavior?

Answer 22

pressure
volume