1. Tardigrade
  2. Question
  3. Chemistry
  4. At 473 K, equilibrium constant, Kc for decomposition of phosphorus pentachloride, PCl5 is 8.3 × 10-3. If decomposition is depicted as: PCl5(g) leftharpoons PCl3(g) +Cl2(g) ; ΔrH°=124.0 kJ mol-1 what would be the effect on reaction if the temperature is increased?

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Q. At $473\,K$, equilibrium constant, $K_c$ for decomposition of phosphorus pentachloride, $PCl_5$ is $8.3 \times 10^{-3}$. If decomposition is depicted as :
$PCl_{5(g)} \rightleftharpoons PCl_{3(g)} +Cl_{2(g)}$ ; $\Delta_{r}H^{\circ}=124.0\,kJ\,mol^{-1}$
what would be the effect on reaction if the temperature is increased?

Equilibrium

Solution:

$K_{c}=\frac{\left[PCl_{3\left(g\right)}\right]\left[Cl_{2\left(g\right)}\right]}{\left[PCl_{5\left(g\right)}\right]}$
As the reaction is endothermic, the increase in temperature will favour the forward reaction. More $PCl_5$ will dissociate to form $PCl_3$ and $Cl_2$.