Question

In which of the following equilibrium $K_{P}=K_{C}$? ________.

• A. $CaCO_{3(s)} \rightleftharpoons CaO_{(s)}+CO_{2(g)}$
• B. $2SO_{2(g)}+O_{2(g)} \rightleftharpoons 2SO_{3(g)}$
• C. $PCl_{5(g)} \rightleftharpoons PCl_{3(g)}+Cl_{2(g)}$
• D. $H_{2(g)}+I_{2(g)} \rightleftharpoons 2HI_{(g)}$
• E. $N_2O_{4(g)} \rightleftharpoons 2NO_{2(g)}$

Hint:

Check if the number of gas molecules is the same on both sides.

Answer 1

The Correct Option is D

Step 1: Concept
$K_P = K_C(RT)^{\Delta n_g}$. $K_P = K_C$ when $\Delta n_g = 0$.

Step 2: Meaning
$\Delta n_g = (\text{moles of gaseous products}) - (\text{moles of gaseous reactants})$.

Step 3: Analysis
In (D): $\Delta n_g = 2 - (1+1) = 0$.

Step 4: Conclusion
Since $\Delta n_g = 0$, $K_P = K_C$. Final Answer: (D)