Q.

The effect of temperature on spontaneity of reactions are represented as:

  ΔH ΔS Temperature Spontaneity
(A) + – any T Non spontaneous
(B) + + low T spontaneous
(C) – – low T Non spontaneous
(D) – + any T spontaneous

 

The incorrect combinations are:                                          [2025]

1 (A) and (D) only  
2 (B) and (D) only  
3 (A) and (C) only  
4 (B) and (C) only  

Ans.

(4)

A reaction is spontaneous if ΔG is negative.

S.no ΔH ΔS T ΔG=ΔH−TΔS Spontaneity
(A) + − any + Non-spontaneous
(B) + + low + Non-spontaneous
(C) − − low − Spontaneous
(D) − + any − Spontaneous