Question

At standard ambient temperature and pressure (SATP), a gas has density of 1.5328g/L. What is the molar mass of the gas?

Answer 1

The standard ambient temperature and pressure are

Temperature =298 K

Pressure = 1atm

The density of gas is 1.5328 g/L

density = mass of gas per unit volume

the ideal gas equation is

PV = nRT

P = pressure = 1 atm

V = volume

n = moles

R= gas constant = 0.0821 Latm/mol K

T = 298 K

moles = mass / molar mass

so we can write

n/V = density / molar mass

Putting values

$Pressure=\frac{nRT}{V}=\frac{massXRT}{VXmolarmass}$

$Pressure=\frac{densityXRT}{molarmass}$

$molarmass=\frac{densityXRT}{Pressure}=\frac{1.5328X0.0821X298}{1}=37.50$

Thus molar mass of gas is 37.50g/mol