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=(nRT)/(V)=(massXRT)/(VXmolarmass)`

`Pressure=(densityXRT)/(molarmass)`

`molarmass=(densityXRT)/(Pressure)=(1.5328X0.0821X298)/(1)=37.50`

Thus molar mass of gas is 37.50g/mol