Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
Assertion A : The reduction of a metal oxide is easier if the metal formed is in liquid state than solid state.
Reason R : The value of Δ G ^Θ becomes more on negative side as entropy is higher in liquid state than solid state.
In the light of the above statements, choose the most appropriate answer from the options given below

Solution

Chemistry ma’am · 4 steps

A liquid metal means more entropy in the products, so -TΔ S° drags Δ G° further down.

1. What easier means. Reduction is a reaction: metal oxide plus reducing agent gives metal plus the oxidised reducing agent. A reduction is easier when its Δ G° is more negative.

   Δ G° = Δ H° - TΔ S°

2. Liquid versus solid. Particles in a liquid move much more freely than in a solid, so a liquid metal has higher entropy than the same metal as a solid. Forming liquid metal therefore makes Δ S° of the reduction more positive.
3. Effect on ΔG. A larger Δ S° makes -TΔ S° more negative, and at the high temperatures used in extraction this term dominates. So Δ G° becomes more negative and the oxide is reduced more easily.
4. So. A is correct, R is correct, and the entropy gain stated in R is exactly why A happens. The answer is (a).

The idea to keep. Easier always means a more negative Δ G°. A product in a more disordered state raises Δ S, and at high temperature the -TΔ S term pulls Δ G down.

Answer from the NTA final answer key. Solution by PrepWiser.