At 700 K, the equilibrium constant, K p , for the reaction 2 SO 3( g ) rightharpoons 2 SO 2( g )+ O 2( g ) is 1.8 × 10-3 atm. The value of K c for the above reaction at the same temperature in moles per litre would be

Question

At 700 K, the equilibrium constant, K p , for the reaction 2 SO 3( g ) rightharpoons 2 SO 2( g )+ O 2( g ) is 1.8 × 10-3 atm. The value of K c for the above reaction at the same temperature in moles per litre would be (A) 1.1 × 10-7 (B) 3.1 × 10-5 (C) 6.2 × 10-7 (D) 9.3 × 10-7

Tardigrade Admin · Accepted Answer

For the reaction, Δ n=1 ∴ Kp=Kc(R T)Δ n=Kc R T ∴ Kc=(Kp/R T) =(1.8 × 10-3 atm /0.082 L a t m K -1 mol -1 × 700 K )=3.13 × 10-5

Q. At $700 K$ , the equilibrium constant, $K_{p}$ , for the reaction $2 S O_{3} (g) ⇋ 2 S O_{2} (g) + O_{2} (g)$ is $1.8 \times 1 0^{- 3} a t m$ . The value of $K_{c}$ for the above reaction at the same temperature in moles per litre would be

$1.1 \times 1 0^{- 7}$

$3.1 \times 1 0^{- 5}$

$6.2 \times 1 0^{- 7}$

$9.3 \times 1 0^{- 7}$

For the reaction,
$Δ n = 1$
$∴ K_{p} = K_{c} (RT)^{Δ n} = K_{c} RT$
$∴ K_{c} = \frac{K _{p}}{RT}$
$= \frac{1.8 \times 1 0 ^{- 3} a t m}{0.082 L a t m K ^{- 1} m o l ^{- 1} \times 700 K} = 3.13 \times 1 0^{- 5}$

Q. At 700K, the equilibrium constant, Kp​, for the reaction 2SO3​(g)⇋2SO2​(g)+O2​(g) is 1.8×10−3atm. The value of Kc​ for the above reaction at the same temperature in moles per litre would be

1.1×10−7

3.1×10−5

6.2×10−7

9.3×10−7