A metal M displaces zinc from ZnCl solution This shows that

Step 1: Analyze the question A metal M displaces zinc from a solution of its salt (written as ZnCl, though it should be ZnCl₂). We need to decide what this tells us about M compared with zinc.

Step 2: The concept In a displacement reaction, a more reactive metal displaces a less reactive metal from its salt solution. Reactivity of metals is linked to electropositivity, which is the tendency to lose electrons and form positive ions.

The reaction is:

M + Zn²⁺ → M²⁺ + Zn

• M loses electrons (it is oxidised).
• Zn²⁺ gains electrons (it is reduced).

Step 3: Evaluate each option

• A. Electrons flow from zinc to M. Wrong. Electrons flow from M to Zn²⁺, the opposite direction.
• B. M is more electropositive than zinc. Correct. M loses electrons more readily than zinc does, so it pushes zinc out of solution.
• C. M is more electronegative than zinc. Wrong. Metals that displace others are more electropositive, not more electronegative.
• D. Zinc is more electropositive than M. Wrong. If this were true, zinc would displace M instead.

Step 4: Answer M sits higher than zinc in the reactivity (electrochemical) series, so it is more electropositive than zinc.

Tip: Remember "the higher metal displaces the lower metal." A displacing metal is always the more reactive, more electropositive one. Examples: Mg displaces Zn, and Zn displaces Cu.