Question

The mass of a gas that occupies a volume of 612.5 ml at room temperature and pressure (25° C and 1 atm pressure) is 1.1 g. The molar mass of the gas is

Options

• 66.25 g mol^-1

• 44 g mol^-1

• 24.5 g mol^-1

• 662.5 g mol^-1

Answer 1

44 g mol^-1

Explanation:

No. of moles of a gas that occupies a volume of 612.5 mL at room temperature and pressure (25° C and 1 atm pressure)

= `(612.5 × 10^-3  "L")/(24.5  "Lmol"^-1)`

= 0.025 moles

We know that,

Molar mass = `"Mass"/"No. of moles"`

= `(1.1  "g")/(0.025  "mol")`

= 44 g mol^-1