An oxide of an element contains $20 \%$ oxygen by weight. Calculate the equivalent weight of the element.

Sulphur forms the chlorides $S_2Cl_2$ and $SCl_2$. The equivalent mass of sulphur in $SCl_2$ is $....... \ g/eq$.

The equivalent weight of a metal is $4.5$ and the molecular weight of its chloride is $80$. The atomic weight of the metal is

What is the atomic mass of $Fe$?
Given abundance of ${}^{54}Fe = 10\%$,${}^{56}Fe = 85\%$,and ${}^{57}Fe = 5\%$.

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 $= 1.008 \ u$)

$1.5 \ g$ of $CdCl_2$ was found to contain $0.9 \ g$ of $Cd$. Calculate the atomic weight of $Cd$.