The equivalent mass of iodine in the following reaction is $I_2 + 2S_2O_3^{2-} \longrightarrow 2I^{-} + S_4O_6^{2-}$

The phosphate of a metal has the formula $MPO_4$. The formula of its nitrate will be

Isotope	Relative abundance $(\%)$	Atomic mass $(u)$
$^{12}C$	$98.8$	$12$
$^{13}C$	$1.18$	$13.1$
$^{14}C$	$0.02$	$14.1$

From the above data,what is the average molecular mass of $CH_4$ containing all isotopes of carbon,assuming hydrogen is only $^{1}_{1}H$? (Given that atomic mass of hydrogen $= 1.008 \ u$)

An element,$X$ has the following isotopic composition:
$^{200}X: 90\%$,$^{199}X: 8.0\%$,$^{202}X: 2.0\%$
The weighted average atomic mass of the naturally occurring element $X$ is closest to......$amu$.

Boron has two stable isotopes,$^{10}B$ $(19\%)$ and $^{11}B$ $(81\%)$. What will be its atomic mass in the periodic table?

The vapor density of a metal chloride is $77$. If the equivalent weight of the metal is $3$,what is its atomic weight?