Question

the equilibrium constant at 250C for the equation PCl5 PCl3 is kp 4.5 x 10^3 bar calculate value of grxn at 250C in which direction is reaction spontaneous when pcl3 cl2 standard conditions

Answer 1

Answer:

-36.6 kJ·mol⁻¹  

Explanation:

1. Calculate ΔG

$\text{The relationship between \Delta G^{\circ} and K is}\\\Delta G^{\circ} = -RT \ln K$

T = (250 + 273.15) K = 523.15 K

$\begin{array}{rcl}\Delta G & = & -8.314 \text{ J}\cdot\text{K}^{-1} \text{mol}^{-1} \times \text{523.15 K} \ln (4.5 \times 10^{3}) \\& = & -4349\text{ J}\cdot \text{mol}^{-1} \times 8.412\\& = & \text{-36 590 J}\cdot \text{mol}^{-1}\\& = & \textbf{-36.6 kJ}\cdot \text{mol}^{-1}\\\end{array}$

2. Direction of spontaneity

ΔG is negative, so the reaction is spontaneous in the forward direction.