Chapter 10 Flashcards
What are vapors?
gaseous state of any substance that normally exists as a liquid or solid
What does the volume of gas=?
volume of tis containter
How are gases highly compressible?
pressure is applied to a gas its volume readily decreases.
Are solids or liquids readily compressible?
no
What kind of a mixture does gases form?
forming homogeneous mixtures
Do all gases exert pressure on any surface if they are in contact?
yes
How do the molecules of gas move?
chaoticllay, colliding with each other and with the walls of their container
How do you find the pressure of gas?
P=F/A
What does A stand for on the equation to find pressure of gas?
area
What does the F in the equation for pressure of gas stand for?
force
What energy of gas overides its gravitational force?
thermal energies of motion(kinetic energies)
What is atmospheric pressure?
as the force exerted by the atmosphere on a given surface area
How do you find the magnitude of atmospheric pressure?
F=ma
What does a stand for in the magnitude eof atmospheric pressure equation?
acceleration
What is the equation to find gravitational force of the atmosphere?
F-=mg
What does g stand for in the graviational force equation?
9.8 m/s^2
What is the units for gravitoanl force?
N or 1kg-m/s^2
How do you go from kPa to bar?
100kPa= 1bar
How does height realte to atmospheric pressure?
the height will increase or decrease as atomspheric pressure increases or decreases
What is standard atmospheric pressure?
corresponds to the typical pressure at sea level 760 torr
What does gas volume do as pressure decreases?
increases
As altitude increases what does atmospheric pressure do?
decreases
What is boyle’s law?
the volume of a fixed quantiy of gas maintined at constant temperature is inversely proportional to the pressure
What is boyles law equation?
PV=constant
When the volume of gas increases what does the temperature do?
increases
What does charles law states?
the volume of a fixed amount of gas maintined at constant pressure is directly proportional to its absolute tempature
What is charles law equation?
V/T= constant
What is avogadro’s hyopthesis?
equal volumes of gases at the same temperature and pressure contain equal number of molecules
What is avagdro’s law?
the volume of a gas maintined at constant temperature and pressure is directly proptotional to the number of moles of the gas
What is avagdro’s equation?
V/n constant
What is the ideal gas equation?
PV=nRT
What is R in the ideal gas equation?
gas contant
What does R equal in the ideal gas law equation?
0.08206 L-atm/Mol x K
What are the standard temparute and pressure?(STP)
T=0˚c and P=1atm and V=22.41L
What is the equation to find pressure when n and t is a constant
P1V1=P2V2
What is the combined gas law equation?
P1V1/T1= P2V2/T2
What is the equation to find density?
d=PM(molar mass)/RT
What happens to the density as molar mass increases?
density increases
What happens to the denisty of the gas as temperature increases?
decreases become less dense
How can you determine the molar mass of gas with density?
M(molar mass)= dRT/P
What is partial pressure?
the pressure exerted by a particular gas in a mixture?
What dalton’s law of partial pressure?
A law stating that the total pressure of a mixture of gases is the sum of the pressures that each gas would exert if it were present alone
How do you find the total pressure of a mixture of gases?
Pt=P1 + P2 + P3+….
How do you calculate the partial pressure of a gas when given the P and the mol precnet?
divide the mole percent by 100 and then times it by the pressure
What is the kinetic molecular theory of gases?
a set of assumptions about the nature of gases
What do large number of molecules in gas do?
are in continous random motion
What is negligible molecular volume?
the combined volume of all the molecules of the gas is negligible relative to the toal volume in which teh gas is contained
What negligible forces?
attractive and repulsive forces between gas molecules
What does average kinetic energy do as temperature remains constant?
doesnt change with time
What is the average kinetic energy of the molecules proportional to?
the absolute temperature
What determines the magnitude of pressure?
how often and how forcefully the molecules strike the walls
When two gases are at the same tempertature what is the average kinetic temperature?
the same
What does molecular motion do as temerpature increases?
increases
What does the range of molecular speed do as temeprature increases?
increases
When there is an increase in volume at constant temperature and the pressure decreases what happens to teh average kinetic energy?
is unchanged
When there is an increase in volume at constant temperature and the pressure decreases,
What happens to the distance between molecules?
move a longer distance between collisions
AS temperature icnreases at constant volume casues pressure to increase,
What happens to the average kinetic energy?
increase in average kinetic energy
When there is an increase in volume at constant temperature and the pressure decreases.
What happens to the amount of collisions?
fewer wall collisions
ASs temperature icnreases at constant volume casues pressure to increase,
What happens to the number of collisions?
more collisions with walls
ASs temperature icnreases at constant volume casues pressure to increase,
What happens to the momentum?
it increases causing more forceful collisions
How do you find rms speed?
√3RT/M(molar mass)
What does the rms speed do as molar mass decreases?
increases
How do you find probable speed of a gas?
√2RT/M(molar mass)
How do you find the average speed of a gas?
√8RT/πM(molar mass)
What will speed do as temperature increases?
increase
What is effusion?
the escape of a gas through an orfice or a hole
What is diffusion
the spreading of one substance throughput a space or throughout a second substance
What units does molar mass have to find the speed of gases?
kg/mol
What does R equal in the speed equations?
8.314 J/mol-k or kg-m^2/s^2-mol-k
What is the effusion rate inversely proportional to?
the square root of its molar mass
How do you find effusion rate?
√M2/M1(molar mass)
If a gas is lighter does it have a high or low effusion rate?
high
What is effusion rate directly proportional to?
the rms speed of molecules
What is another equation to find effusion rate?
rms1/rms 2 or √3RT/M1/ RT/M2
How do you use the ideal gas law to solve for n(moles)
PV/RT=n
What does temerpature cause ideal behavior to do?
the deviation from ideal behavior increases
What is the van der waals equation?
(P + n^2/a/V^2)(V-nb)=nRt
Why is there a pressure adjustment for the nonideal behavior?
molecules attract and repel each other
Why is there a volume adjustment for the nonideal behavior?
molecules occupy some space on their own
When using the rms speed equation what is the molar mass units?
kg/mol
When using the rms speed equation what does the R constant equal?
8.314
In the rms speed equation what does the Tempature units have to be?
Kelvins
How to find the rate of effusion?
Divide the molar masses and then take the square root
√M2/M1
Which of the following will lead to an increase in the mean free path of gas molecules in a closed container?
Increase V
without changing T
Open valve to release half the molecules without changing T
or V
.
Is ionic compounds boiling points alwyas smaller or bigger?
bigger
What is the first step in determing which boiling point is smaller or larger?
seeing if they are polar or not
If a molecule is polar and the other molecule is nonpolar who has the bigger boiling point?
polar molecule
What is the second step in determing which boling points is smaller or larger?
By the molecular weight if both are nonpolar which ever molecule has a larger weight
What is the third step in determing which boiling point is smaller or larger? If they are both polar
if they are both polar looking at the other intermolecular forces
If one molecule can do hydrogen bonding and is polar and another molecule is polar but can’t do hydrogen bonding which molecule has the largerst boiling point?
the molecule that can do hydrogen bonding
