Chem test 2 Flashcards
What is the kinetic theory of matter?
- 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)
What are the characteristics of gasses?
- 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
What is Avagadros number?
6.022 X1023 = 1mol
kinetic theory of gases:
- 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
Root mean squared velocity is what?
the speed that is directly associated with the average kinetic energy of the gas molecules
if a gas has a low molar mass, its speed will be ______ than one with a higher molar mass
greater
how to solve for kelvin
C + 273.15
define atmospheric pressure
the weight of air per unit of area
wt. of air/ area
define pressure
the amount of force applied to an area
force/area
what is Boyle’s law?
the pressure of a gas is inversely related to it’s volume when temperature is constant
P1V1=P2V2
what is Charle’s law?
The temperature of a gas is directly related to volume
V1/T1 = V2/T2
What is Gay-Lussac’s law?
the pressure exerted by gas is directly related to the temperature of the gas
P1/T1 = P2/T2
What is the combined gas law?
The combination of Boyles, Charles, and Gay-Lussac’s laws where n (number of moles) are constant
What is avogadros law?
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
What is the ideal gas law?
pV=nRT
What is Dalton’s law?
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
Ptotal= P1+P2+3….. etc
What is effusion?
the escape of gas molecules through a tiny hole into an evacuated space
What is diffusion?
the spread of one substance throughout a space or a second substance (from high to low concentration)
What is grahams law?
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
What is Henry’s law?
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
in the real world, the behavior of gases conforms to the ideal gas law only at
relatively high temperature or low pressure
What kind of adjustments can be made to the ideal gas law to take into account deviation from ideal behavior?
pressure
volume
