Question

For the reaction, $N _{2}( g )+3 H _{2}( g ) \rightleftharpoons 2 NH _{3}( g )$, the unit of $K$ is :

• A. $L\,mol ^{-1}$
• B. $L^{2} \,mol^{-2}$
• C. $mol\,L ^{-1}$
• D. No units

Answer 1

The Correct Option is B

$N _{2}( g )+3 H _{2}( g ) \rightleftharpoons 2 NH _{3}( g )$
$K =\frac{\left[ NH _{3}\right]^{2}}{\left[ N _{2}\right]\left[ H _{2}\right]^{3}}=\frac{\left[\frac{ mol }{ L }\right]^{2}}{\left[\frac{ mol }{ L }\right]\left[\frac{ mol }{ L }\right]^{3}}$
$K =\left[\frac{ mol }{ L }\right]^{-2}= L ^{2} \,mol ^{-2}$