Question

Which of the following combinations will result in a reaction that is spontaneous at all temperatures?

Answer 1

Answer:

$\huge\boxed{Option \ 2}$

Explanation:

A reaction is spontaneous at all temperatures by the following combinations:

=> A negative enthalpy change ( $\triangle H < 0$ )

=> A positive entropy change ( $\triangle S > 0$ )

See the attached file for more better understanding!

Answer 2

from Gibbs Equation, $\Delta G = \Delta H - T\Delta S$

reaction is spontaneous if $\Delta G$ is negative.

so, first option is not valid at high temperature, ($-h+ts$)

second, is always a spontaneous reaction, ($-h-ts$)

third, is never spontaneous ($+h+ts$)

4th is similar to second, spontaneous at higher temperatures ($+h-ts$)