Given that the abundances of isotopes $^{54}Fe$,$^{56}Fe$ and $^{57}Fe$ are $5 \%$,$90 \%$ and $5 \%$,respectively,the atomic mass of $Fe$ is

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

If $A$,$E$,$M$,and $n$ represent atomic mass,equivalent mass,molecular mass,and valency of an element respectively,which of the following relations is correct?

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......$amu$.

What is the equivalent weight of methanol if one mole of $CH_3OH$ is combusted to form $CO$ and $H_2O$?

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 $= 1.008 \ u$)