Answer: -1.
- A 0
- B +1
- C -1
- D +2
Correct answer: C. -1
Explanation: Fluorine is the most electronegative element; it always has an oxidation state of -1 in all its compounds.
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.