Question

For which of the following reactions, $K_P=K_C$ ?

• A. $PC{l}_3\left(g\right)+C{l}_2\left(g\right)\leftrightharpoons PC{l}_5\left(g\right)$
• B. $H_2\left(g\right)+C{l}_2\left(g\right)\leftrightharpoons 2HCl\left(g\right)$
• C. $N_2\left(g\right)+3H_2\left(g\right)\leftrightharpoons 2N{H}_3\left(g\right)$
• D. $CaC{O}_3\left(s\right)+\leftrightharpoons CaO\left(s\right)+C{O}_2\left(g\right)$

Answer 1

The correct option is B $H_2\left(g\right)+C{l}_2\left(g\right)\leftrightharpoons 2HCl\left(g\right)$

$K_P=K_C(RT{)}^{\Delta n_g}$
if $\Delta n_g=0,K_P=K_C$
$\Delta n_g$ is the number of moles of gaseous products - number of moles of gaseous reactants in a balanced equation.
for reaction in (b) $\Delta n_g=0$
so, for (b), $K_P=K_C$