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Question #44233
The Question
A closed reaction vessel at contains a standard acidic aqueous solution (). To this, of and of are added. The system is allowed to reach complete thermodynamic equilibrium.
Given the standard reduction potentials at :
Calculate the total standard Gibbs free energy change () for the complete conversion of the given amounts of reactants to their most thermodynamically stable products. (Assume ideal behavior, standard states for all species except the initial stoichiometric amounts provided, and )
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Exception_Exposure
Learn to identify edge cases and boundary exceptions that JEE examiners hide in math problems.
Concepts Behind This Question
Hess's Law Application|Comproportionation Reversibility|Oxidation State Extremes
Why This Question Is Tricky
Common Mistakes
The problem tests the distinction between a stoichiometric intermediate state and the true thermodynamic ground state.
The 1:4 reactant ratio perfectly baits students into calculating the for the comproportionation to , which yields exactly .
The hidden variable is the thermodynamic instability (metastability) of in aqueous acidic medium, which disproportionates into and .
Students must apply Hess's Law (or Frost diagram analysis) to bypass the metastable intermediate and calculate the free energy change for the complete resolution to the thermodynamically stable products.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Thermodynamics - Class 11 Part 1 |
| Concept | Hess's Law Application |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |