Question

A reaction has $\Delta$H = – 33 kJ and $\Delta$S = – 58$\frac{J}{K}$. This reaction would be :

• A. Spontaneous at all temperatures
• B. Non-spontaneous at all temperatures
• C. Spontaneous above a certain temperature
• D. Spontaneous below a certain temperature

Answer 1

Answer: (D)

Spontaneous below a certain temperature

Answer 2

$\Delta$G = ($\Delta$H) – T($\Delta$S)

$\downarrow$ $\downarrow$

–ve –ve

since both are –ve, the reaction would have a –ve $\Delta$G below a temperature of $\frac{33000}{58}$ K ( = 569K)