A reaction has Delta H=-100 kJ mol^-1 and Delta S=-200 J mol^-1K^-1 (temperature independent). Select the correct statement(s).

It becomes non-spontaneous above 500 K.

Delta G at 298 K is -159.6 kJ mol^-1.

It becomes non-spontaneous above 500 K.

It is spontaneous at all temperatures.

JEE Main levelOne or more correct optionsDifficulty 2 of 3td143

A reaction has $Δ H = - 100 kJ mo l^{- 1}$ and $Δ S = - 200 J mo l^{- 1} K^{- 1}$ (temperature independent). Select the correct statement(s).

Δ G = Δ H - T Δ S = - 100000 - 298 (- 200) = - 40400 J = - 40.4 kJ

298 K

, so it is spontaneous there, and statement 2 (

- 159.6

) is wrong.

Δ G = 0

T = Δ H /Δ S = 500 K

; above it the positive term

- T Δ S

dominates and

Δ G > 0

. It is therefore not spontaneous at all temperatures.