The average molar mass of chlorine is $35.5 \ g \ mol^{-1}$. The ratio of $^{35}Cl$ to $^{37}Cl$ in naturally occurring chlorine is close to : (in $:1$)

The molecular weight of a tribasic acid is $M$. What will be its equivalent weight?

Assertion : The normality of $0.3 \ M$ aqueous solution of $H_3PO_3$ is equal to $0.6 \ N$.
Reason : Equivalent weight of $H_3PO_3 = \frac{\text{Molecular weight of } H_3PO_3}{3}$

An element $X$ reacts with oxygen to form a compound $X_2O_3$. If the atomic mass of $X$ is $91.5$,the equivalent mass of $X$ is:

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:

Atomic weight of $Ne$ is $20.2$. If $Ne$ is a mixture of $Ne^{20}$ and $Ne^{22}$,what is the percentage abundance of the lighter isotope?