JEE Main & Advanced Chemistry Thermodynamics / रासायनिक उष्मागतिकी Sample Paper Topic Test - Thermo Chemistry (Thermodynamics)

The gaseous endothermic reaction : \[P+Q\to 3R\] at \[327{}^\circ C\] takes place spontaneously, because-

A) \[\Delta H<0;\,\Delta S<0\]

B) \[\Delta H>0;\,\Delta S>0\]

C) \[\Delta H<0;\,\Delta S>0\]

D) \[\Delta H>0;\,\Delta S<0\]

Correct Answer: B

Solution :

[b] \[\Delta G=\Delta H-T\Delta S\]

For an endothermic reaction \[\Delta H=+ve\]

[less molecules \[\to \] more molecules],

\[\Delta H=+ve\]

\[\therefore \] \[T\Delta S>\Delta H,\] and \[\Delta G=-ve\]

Hence, the reaction occurs spontaneously.