We are given the molecular mass of tetraoxosulphate(VI) acid as 98 g/mol. The molecular formula of this is H₂SO₄ which is also known as sulfuric aid. The vapour density of a substance is the density of a vapour in relation to hydrogen gas. Therefore, it the mass of a volume of gas, divided by the mass of the same volume of hydrogen gas. We can use the following formula:
vapour density = molar mass of gas/ molar mass of H₂
vapour density = 98 g/mol H₂SO₄ / 2 g/mol H₂
vapour density = 49
The vapour density of tetraoxosulphate(IV) acid is found to be 49. It should also be noted that the vapour density is a unitless quantity.
