As a gas (insoluble in liquid) is bubbled through a liquid, part of the liquid vaporises and these v — States of Matter and Gaseous State Chemistry Question
Question
As a gas (insoluble in liquid) is bubbled through a liquid, part of the liquid vaporises and these vapours are carried off with the gas. As a sample of dry nitrogen gas is bubbled through a liquid, it is found that under identical conditions of temperature and pressure, a definite volume of wet nitrogen gas weighs more than the equal volume of dry nitrogen gas. Hence, the liquid through which dry nitrogen gas was passed, may be
💡 Solution & Explanation
Let the molecular weight of the dry gas be M_gas (for $N_2$, M = 28 g/mol) and the molecular weight of the vaporized liquid be M_liq. In the mixture, some nitrogen molecules are replaced by liquid vapour molecules. For the wet gas to be heavier than dry gas, the vaporized liquid must have a higher molecular weight than nitrogen (28 g/mol). Molar masses: Water (18), Benzene (78), $CCl_4$ (154), Heavy water (20). Thus, Benzene and $CCl_4$ are heavier than $N_2$ and will increase the density of the gas mixture.