Question

Calculate the moles of hydrogen present in a $500c{m}^3$ sample of hydrogen gas at a pressure of $760mm$ of $Hg$ and ${27}^{\circ }C$.

Answer 1

$500c{m}^3=0.5L,760mm$ of $Hg=1atm$.

Now apply the gas equation, $n=\frac{PV}{RT}$
$n=\frac{1\times 0.5}{0.0821\times 300}$

$⟹n=2.03\times {10}^{-2}mol$