Suppose you are given two flasks at the same temperature,

Step 1 of 2

Given:

Let the flask A has volume  = 2L

Mass of gas = 4.8 g

Pressure = X atm

It is known that according to ideal gas equation, PV = nRT

Or, \(\mathrm{PV}=\frac{\text { Given mass }}{\text { Molar mass }} \times \mathrm{R} \times \mathrm{T}\)

Or, \(\text { Molar mass }=\frac{\text { Given mass } \times R \times T}{P V}\)

Substituting the values in the above equation, the molar mass can be calculated as,

\(\text { Molar mass }=\frac{4.8 \mathrm{~g} \times 0.0821 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \times T}{X \mathrm{~atm} \times 2 \mathrm{~L}}=\frac{0.197 \mathrm{~g} / \mathrm{mol} \mathrm{T}}{X}\)