In a Victor Meyer's apparatus,$510 \ mg$ of a liquid on vaporization displaces $67.2 \ cm^3$ of dry air at $NTP$. What is the molecular weight of the liquid?

On what basis is the modern atomic mass standard defined?

In order to prepare one litre of a $1 \ N$ (normal) solution of $KMnO_4$,how many grams of $KMnO_4$ are required if the solution is used in an acidic medium for oxidation?

Among $10^{-9} \ g$ (each) of the following elements,which one will have the highest number of atoms?
Element: $Pb, Po, Pr$ and $Pt$

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

Isotope	Natural abundance (%)	Molar mass $(u)$
$^{35}Cl$	$75.77$	$34.9689$
$^{37}Cl$	$24.23$	$36.9659$

(in $u$)

An element has two main isotopes of mass numbers $85$ and $87$. In nature,they occur in the ratio of $75\%$ and $25\%$ respectively. The atomic weight of the element will be approximately: