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Question #44681
The Question
A metal (Atomic mass = ) forms two chlorides, and . Elemental analysis reveals that of combines with of chlorine in compound , and with of chlorine in compound .
of solid is dissolved in of water at . Upon dissolution, the metal ion undergoes complete disproportionation into solid metal and the higher oxidation state metal ion found in .
The resulting aqueous mixture is filtered, and the filtrate is electrolyzed using a current of for . Due to concurrent gas evolution at the cathode, the current efficiency for the deposition of is only .
Calculate the total mass of solid metal recovered from both the initial dissolution process and the subsequent electrolysis. (Given: , Atomic mass of )
Options
- A.
25.3 g
- B.
6.9 g
- C.
26.8 g
- D.
2.3 g
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Numerical_Precision
Improve calculation stamina and avoid rounding errors in high-stakes competitive examinations.
Concepts Behind This Question
Law of Multiple Proportions|Equivalent Concept in Redox|Electrolysis Product Prediction
Why This Question Is Tricky
Common Mistakes
This problem tests the intersection of stoichiometry (Law of Multiple Proportions) and electrochemistry, specifically targeting the assumption that metal ions remain stable in aqueous solutions.
The 'Hidden Variable' is the disproportionation of the +1 oxidation state (common for Group 13 metals like Indium) before electrolysis even begins.
Students who blindly apply Faraday's laws to the initial 0.30 moles of M+ will fall into the trap of calculating deposition based on a 1-electron reduction, completely missing the 23.0 g of metal precipitated chemically and the altered n-factor (3) for the remaining ions.
Furthermore, the non-ideal current efficiency (60%) due to concurrent H2 evolution acts as a secondary kinetic trap, punishing those who assume 100% Faradaic yield.
Quick Facts About This Question
Question Information
| Subject | Chemistry |
| Chapter | Some Basic Concepts of Chemistry - Class 11 Part 1 |
| Concept | Law of Multiple Proportions |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |