2) If I have an unknown quantity (# of moles) of gas at a pressure of 32 atm, a volume of 70 L, and a temperature of 25˚C. How many moles of gas are in the sample?

91.5 mol

Explanation:

Volume of gas = 70 L

Temperature = 25°C

Pressure = 32 atm

Moles of gas  = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K  

T = temperature in kelvin

Now we will convert the temperature.

25+273.15 = 298.15 K

By putting values,

32 atm × 70 L = n ×0.0821 atm.L /mol.K × 298.15 K

2240 atm.L = n ×24.48 atm.L /mol

n = 2240 atm.L / 24.48  atm.L /mol  

n = 91.5 mol