JEE chemistry

For a reaction, Δ H = -40 kJ/mol and Δ S = -100 J/mol·K at T = 400 K — JEE Chemistry

PIPooja Iyer · 11 Asked 1mo ago 329 views 1 answer

For a reaction, $\Delta H = -40$ kJ/mol and $\Delta S = -100$ J/mol·K at $T = 400$ K. Determine if the reaction is spontaneous.

1 Answer

VCVarun Choudhary ✓ Accepted · 1mo ago ▲ 5

$$\Delta G = \Delta H - T\Delta S = -40000 - 400\times(-100)$$

$$= -40000 + 40000 = 0 J/mol$$

The system is at equilibrium at 400 K. Below 400 K, $\Delta G < 0$ (spontaneous). Above 400 K, $\Delta G > 0$ (non-spontaneous).

Log in to post your own answer or join the discussion.

Discussion (2)

N
For revision — the key formula used here comes up almost every year.
NabinThapa70 · 1mo ago
AS
Thanks a ton, I was stuck on this exact problem for an hour.
Arjun Sharma · 1mo ago
← Back to all questions