The degree of dissociation of a weak acid is $7.2 \times 10^{-4}$. What is the value of its percent dissociation in a $0.025 \ M$ solution (in $\%$)?

For which of the following reactions,the degree of dissociation cannot be calculated from the vapour density data?
$I. \ 2HI_{(g)} \rightleftharpoons H_{2(g)} + I_{2(g)}$
$II. \ 2NH_{3(g)} \rightleftharpoons N_{2(g)} + 3H_{2(g)}$
$III. \ 2NO_{(g)} \rightleftharpoons N_{2(g)} + O_{2(g)}$
$IV. \ PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$

Consider the following gas phase dissociation, $PCl_{5(g)} \rightleftharpoons PCl_{3(g)} + Cl_{2(g)}$ with equilibrium constant $K_P$ at a particular temperature and at pressure $P$. The degree of dissociation $(\alpha)$ for $PCl_{5(g)}$ is

The vapor density of a gas is $11.2$. At $N.T.P.$,$11.2 \ g$ of this gas occupies a volume of ............. $litres$.

For the equilibrium $PCl_{5_{(g)}} \rightleftharpoons PCl_{3_{(g)}} + Cl_{2_{(g)}}$,the observed vapour density of the mixture is $80$. Given atomic masses $P = 31$ and $Cl = 35.5$,the degree of dissociation of $PCl_{5_{(g)}}$ is approximately....$\%$

$4 \ mol$ of $PCl_5$ is heated in a closed vessel at a constant temperature. If the degree of dissociation for $PCl_5$ is $0.5$,what will be the total number of moles at equilibrium?