$A$ metal oxide has $40\%$ oxygen by mass. The equivalent weight of the metal is:

In the reaction $SO_2 + 2H_2S \rightarrow 3S + 2H_2O$,the equivalent mass of the oxidizing agent is .....

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 ......

The equivalent weight of a divalent metal is $31.82$. The weight of a single atom is

An alloy of metals $X$ and $Y$ weighs $12 \ g$ and contains atoms $X$ and $Y$ in the ratio of $2:5$. The percentage of metal $X$ in the alloy is $20$ by mass. If the atomic mass of $X$ is $40$,what is the atomic mass of metal $Y$ (in $amu$)?

One gram of hydrogen is found to combine with $80 \ g$ of bromine. One gram of calcium (valency $= 2$) combines with $4 \ g$ of bromine. The equivalent weight of calcium is: