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

-36.6 kJ·mol⁻¹

Step-by-step 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) * \text{523.15 K} \ln (4.5 * 10^(3)) \\& = & -4349\text{ J}\cdot \text{mol}^(-1) * 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.