#### Question

The equilibrium constant Kp for the reaction,

H_{2(g)} + I_{2(g)} → 2HI_{(g)} is 130 at 510 K. Calculate ΔG^{o} for the following reaction at the same temperature: 2HI_{(g)} → H_{2(g)} + I_{2(g)} [Given: R = 8.314 J K^{-1} mol^{-1} ]

#### Solution

Given: H_{2(g)} + I_{2(g)} ⇌ 2HI_{(g)}; Kp = 130, T = 510 K, R = 8.314 J K^{-1} mol^{-1}

To find: ΔGº for reaction, 2HI_{(g)} ⇌ H_{2(g)} + I_{2(g)}

Formula: ΔGº = -2.303 RT log_{10}K_{p}

Calculation:

H_{2(g)} + I_{2(g)} ⇌ 2HI_{(g)}; Kp = 130,

2HI_{(g)⇌}H_{2(g)} + I_{2(g)} ; Kp = 1/130

ΔGº= - 2.303 RT log_{10}K_{p}

_{=}-2.303 x 8.314 x 510 x log_{10} (1/130)

= 20642.7 J mol^{-1}

=20.64 kJ mol^{-1}

Is there an error in this question or solution?

#### APPEARS IN

Solution The equilibrium constant Kp for the reaction, H2(g) + I2(g) → 2HI(g) is 130 at 510 K. Concept: Chemical Thermodynamics and Energetic - Equilibrium Constant.