Question

Twice the vapour density gives ______.

Options

• actual vapour density

• relative vapour density

• molecular mass

• molar volume

Answer 1

Twice the vapour density gives molecular mass.

Explanation:

Molecular mass because vapour density is defined as the ratio of the mass of a certain volume of gas to the mass of an equal volume of hydrogen gas, which has a molecular mass of 2. This relationship is mathematically expressed as vapour density = molecular mass/2, meaning that multiplying the vapour density by two directly gives the molecular mass of the gas.