Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. [2025]

STUDY MATERIALS
COURSES
MORE
SUCCESS STORY
ADMISSION
STORE

Back

JEE ADVANCE

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

JEE MAIN

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

NEET

CLASS XI - XII
CRASH COURSE

CLASS XI - XII

CRASH COURSE

BITSAT

CLASS XI - XII

CLASS XI - XII

CBSE BOARD

CLASS IX

CLASS X

CLASS XI

CLASS XII

CLASS VI

CLASS VII

CLASS VIII

UP BOARD

CLASS IX
CLASS X
CLASS XI
CLASS XII

CLASS IX

CLASS X

CLASS XI

CLASS XII

CUET

CRASH COURSE

CRASH COURSE

Courses

CLASSROOM COURSES
ONLINE COURSES

ONLINE COURSES

Q.
Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. [2025]

1 Both $Δ H$ and $Δ S$ are (–ve)

2 Both $Δ H$ and $Δ S$ are (+ve)

3 $Δ H$ is (–ve) but $Δ S$ is (+ve)

4 $ΔH$ is (+ve) but $ΔS$ is (–ve)

Ans.
(2)

For reaction to be spontaneous $Δ G = Δ H - T Δ S < 0$ . As the reaction is endothermic, $Δ H > 0$ . If $Δ S > 0$ , then at low temperature $Δ G$ becomes positive i.e. reaction becomes non-spontaneous, and at high temperature $Δ G$ becomes negative i.e. the reaction becomes spontaneous.

Solution

Q.
Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. [2025]

1 Both $Δ H$ and $Δ S$ are (–ve)

2 Both $Δ H$ and $Δ S$ are (+ve)

3 $Δ H$ is (–ve) but $Δ S$ is (+ve)

4 $ΔH$ is (+ve) but $ΔS$ is (–ve)

Want Us to Email you About Special Offers & Updates?

Solution

Q. Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. [2025]

1 Both ΔH and ΔS are (–ve)

2 Both ΔH and ΔS are (+ve)

3 ΔH is (–ve) but ΔS is (+ve)

4 ΔH is (+ve) but ΔS is (–ve)

Ans. (2) For reaction to be spontaneous ΔG=ΔH−TΔS<0. As the reaction is endothermic, ΔH>0. If ΔS>0, then at low temperature ΔG becomes positive i.e. reaction becomes non-spontaneous, and at high temperature ΔG becomes negative i.e. the reaction becomes spontaneous.

Want Us to Email you About Special Offers & Updates?

Q.
Let us consider an endothermic reaction which is non-spontaneous at the freezing point of water. However, the reaction is spontaneous at boiling point of water. Choose the correct option. [2025]

1 Both $Δ H$ and $Δ S$ are (–ve)

2 Both $Δ H$ and $Δ S$ are (+ve)

3 $Δ H$ is (–ve) but $Δ S$ is (+ve)

4 $ΔH$ is (+ve) but $ΔS$ is (–ve)