An appropriate method for molecular weight determination of chloroform $(CHCl_3)$ is:

The equivalent weights of $H_3PO_4$ in the following reactions are respectively:
$H_3PO_4 + OH^{-} \rightarrow H_2PO_4^- + H_2O$
$H_3PO_4 + 2OH^{-} \rightarrow HPO_4^{2-} + 2H_2O$
$H_3PO_4 + 3OH^{-} \rightarrow PO_4^{3-} + 3H_2O$

Assertion : Equivalent weight of a base $= \frac{\text{Molecular weight}}{\text{Acidity}}$
Reason : Acidity is the number of replaceable hydrogen atoms in one molecule of the base.

Equivalent weights of $X_2Y$ and $X_2Y_3$ are $38$ and $18$ respectively. Find the atomic masses of $X$ and $Y$:-

The atomic weight of $Ne$ is $20.2$. It is a mixture of $Ne^{20}$ and $Ne^{22}$. What is the relative abundance of the heavier isotope (in $\%$)?

Calculate the average atomic mass of hydrogen using the following data:

Isotope	$\%$ Natural abundance	Molar mass
$^1H$	$99.985$	$1$
$^2H$	$0.015$	$2$