1.3 Flashcards
Express the Ideal Gas Law
PV=nRT
what is the ideal gas law?
It is an:
- empirical law: based on experimental observations
- explains the behavior of gases over a limited range of conditions
-macroscopic explanation: does not describe microscopic behavior of particles in gas
V~ nT/P
- most simple gases exhibit nearly ideal gas behavior at ordinary temperatures and pressures
What does R stand for and what is its value?
- R is the universal gas constant
- R= 8.314J mol-1 K-1
When one of the variables have changed; and you are given only two variables eg. P and T; and T was changed; should you use ideal gas law equation of another law?
another law, which is gay lussacs’ law
find T2 by
P1/T1 = P2/T2
(because only one variable was changed and that they weren’t asking for an unknown (that’s when the ideal gas law is used))
true or false the density of a gas is proportional to molar mass?
true
d~M
find M using the ideal gas law
d= m/V= PM/RT M= dRT/P
express density (g L-1 in gas)
mass/volume
What is Dalton’s law of partial pressures?
total pressure of gas mixture is sum of the partial pressures of individual gases in the mixture
What causes partial pressure?
due to pressure exerted by unreacting gases in a gas mixture
why does a hot air balloon rise?
n~ 1/T
when V and P are fixed
(substances of low density float on substances of high density; hot air is less dense than cold air)
true or false: each gas in a mixture is considered independent?
true
true or false: all gases in mixture have the same V and T
true
true or false: the kinetic molecular theory, states that particles in gas behave independently
true
true or false: all gases in mixture have volume of container
true
how do you determine the partial pressure of a gas?
multiply the total pressure of mixture by fractional composition of the gas
express dalton’s law of partial pressures
P total= n total (RT/V); assume that our gas mixture occurs at the same volume and temperature
How do you collect a gas?
by displacing water from a container
true or false; when temperature increases, vapor pressure of water increases
true
gas mixtures in contact with WATER; how does dalton’s law of partial pressures apply?
when a gas is in contact with water, the total pressure is the sum of the gas pressure AND the vapor pressure of water at the given temperature
what dos vapour refer to?
a sample of gas above a liquid
true or false : water vapor also occurs in collected gas?
true
true or false: partial pressure of water vapor (vapor pressure) DEPENDS ONLY ON TEMPERATURE?
true
If asked to find the partial pressure of dry gas (take away the partial pressure of water vapor from the total pressure)
…yep
