Which method is used to determine the molecular mass of a volatile substance?

Complete reaction of $2.0 \, g$ of calcium (at. wt. $= 40$) with excess $HCl$ produces $1.125 \, L$ of $H_2$ gas. Complete reaction of the same quantity of another metal $M$ with excess $HCl$ produces $1.85 \, L$ of $H_2$ gas under identical conditions. The equivalent weight of $M$ is closest to

Elements $X$ and $Y$ form compounds $X_2Y_3$ and $X_3Y_4$ respectively. If $0.2 \ mol$ of $X_2Y_3$ weighs $32.0 \ g$ and $0.4 \ mol$ of $X_3Y_4$ weighs $92.8 \ g$,then the atomic masses of $X$ and $Y$ are respectively:

If the equivalent weight of a metal $(M)$ is $x$ and the formula of its oxide is $M_mO_n$,then the atomic weight of $M$ is ......

What will be the equivalent weight of a metal if the vapour density of the chloride salt of a trivalent metal is $81.25$?

An oxide of an element contains $67.67\%$ oxygen and the vapour density of its volatile chloride is $79$. What is the atomic weight of the element?