Answer: -1.
- A 0
- B -1
- C +1
- D +3
Correct answer: B. -1
Explanation: In NH₂OH: H is +1 (two H on N, one on O), O is -2. Summing: N + 2(+1) + (-2) + (+1) = 0. N + 1 = 0. N = -1. Hydroxylamine has nitrogen in the -1 oxidation state, intermediate between NH₃ (-3) and N₂ (0).
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.