Question

Two statements are given below.
Statement I: The reaction Cr$_2$O$_3$ + 2Al → 2Cr + Al$_2$O$_3$ (ΔG° = -421 kJ) is thermodynamically feasible.
Statement II: The above reaction occurs at room temperature.
The correct answer is

• A. Both the statements I \& II are correct.
• B. Both the statements I \& II are not correct.
• C. Statement I is correct, but statement II is not correct.
• D. Statement I is not correct, but statement II is correct.

Hint:

For reactions with a negative Gibbs free energy (ΔG°), the reaction is thermodynamically feasible. However, the reaction may still require high temperatures or activation energy to occur.

Answer 1

The Correct Option is C

Aluminothermic Reaction Analysis

• Statement I: The reaction \( \text{Cr}_2\text{O}_3 + 2\text{Al} \rightarrow 2\text{Cr} + \text{Al}_2\text{O}_3 \) is thermodynamically feasible as the Gibbs free energy change \( (\text{G}^\circ = -421 \text{ kJ}) \) is negative, indicating that the reaction is spontaneous. Therefore, Statement I is correct.
• Statement II: The reaction does not occur at room temperature because it is an aluminothermic reaction, which requires high temperatures to overcome the activation energy barrier. Therefore, Statement II is incorrect.

Conclusion:

Hence, the correct answer is that Statement I is correct, but Statement II is not correct.