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

$10 \text{ g}$ of a metal $(M)$ reacts with oxygen to form $11.6 \text{ g}$ of oxide. What is the equivalent weight of $M$?

What do you mean by molar weight?

The average molecular weight of the air which has $21 \%$ of $O_2$ and $79 \%$ of $N_2$,is

The equivalent weight of potassium permanganate $(KMnO_4)$ in an acidic solution is:

If $m_1 \ g$ of metal $A$ displaces $m_2 \ g$ of another metal $B$ from its salt solution,and their equivalent weights are $E_1$ and $E_2$ respectively,how is the equivalent weight of $A$ expressed?