Answer: 31.6.
- A 158
- B 31.6
- C 79
- D 52.7
Correct answer: B. 31.6
Explanation: In acidic medium Mn goes +7 to +2 (n-factor 5), so equivalent weight = 158/5 = 31.6 g.
Electron transfer in a redox reaction: zinc loses electrons (oxidised, acts as reducing agent) and copper(II) ions gain those same electrons (reduced, acts as oxidising agent).
Concept context
Master electron transfer in chemistry: assign oxidation states, balance half-reactions, identify oxidising and reducing agents, and connect redox to everyday reactions.