Which of the following statements is/are correct? A. Iron can replace zinc…

Concept: The reactivity series of metals ranks metals by how readily they lose electrons to form positive ions. A metal placed higher in this series is more reactive and can displace a less reactive metal from an aqueous solution of that metal's salt; a metal cannot displace another metal that is more reactive than itself. The order relevant here is Zinc > Iron > Copper.

Application: Checking each statement against this order, one step at a time:

1. Statement A says iron displaces zinc from zinc sulphate (ZnSO4). Since zinc is more reactive than iron, iron cannot push zinc out of its salt solution — no reaction occurs, so statement A does not hold.

2. Statement B says zinc displaces copper from copper sulphate (CuSO4). Zinc is more reactive than copper, so zinc atoms give up electrons and enter solution as Zn2+ ions, while Cu2+ ions gain electrons and deposit as metallic copper: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s). This reaction is chemically valid, so statement B holds.

3. Statement C says copper displaces iron from iron sulphate (FeSO4). Copper is less reactive than iron, so copper cannot push iron out of its salt solution — no reaction occurs, so statement C does not hold.

Cross-check: This matches the standard reactivity-series demonstration: a zinc strip placed in blue copper sulphate solution turns the solution paler as reddish copper deposits on the zinc, while an iron nail in zinc sulphate solution and a copper wire in iron sulphate solution both show no change. Among the three, only the zinc-copper displacement is valid, so the combination that holds is the one containing only statement B.