5.4 Rearrangements of the Ideal Gas Laws

Question 1

The density of a gas

Answer 1

PV = (m/M) x RT
or…
d = (M x P) / RT

• The density of the a gas is directly proportional to its molar mass

Question 2

The Molar Mass of gas

Answer 2

n = (m/M) = (PV/RT)
so…
M = (mRT/PV)

Question 3

partial pressure

Answer 3

equal to the pressure it would exert by itself

Question 4

Dalton’s Law of Partial Pressure

Answer 4

in a mixture of unreacting gasses, the total pressure is the sum of the partial pressures of the individual gasses:
Ptotal = P1 + P2 + P3…

Question 5

mole fraction (x)

Answer 5

a fraction of the total # of moles in the mixture

multiplying X by 100 gives the MOLE PERCENT

Question 6

Partial Pressure of a gas (equation)

Answer 6

P(a) = X(a) x Ptotal

if total pressure multiplied by the mole fraction of (a), X(a)

Question 7

How to determine yield of a gas collected over water

Answer 7

1. look up the vapor pressure at the temperature of the experiment
2. subtract it from the total gas pressure (Ptotal) to get the partial pressure of the gaseous product (Pgas)