The equivalent weight of a divalent metal is $31.82$. The weight of one atom of this metal is:

What will be the mass of one atom of ${}^{12}C$?

In the reaction $2Na_2S_2O_3 + I_2 \to Na_2S_4O_6 + 2NaI$,the equivalent weight of $Na_2S_2O_3$ (molecular weight = $M$) is equal to:

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

The oxide of a metal contains $40 \%$ of oxygen. The valency of the metal is $2$. What is the atomic weight of the metal?

Calculate the molecular mass of the following:
$(i)$ $H_{2}O$
$(ii)$ $CO_{2}$
$(iii)$ $CH_{4}$