PrepRung
Sign inSign up free

NDA 2018 GAT · General Knowledge · Chemical Reactions · medium

When a zinc rod is placed in copper sulphate solution, the blue colour fades and a reddish-brown deposit forms. The reaction is an example of

Single correct option

When a zinc rod is placed in copper sulphate solution, the blue colour fades and a reddish-brown deposit forms. The reaction is an example of
  1. A. decomposition reaction
  2. B. displacement reaction
  3. C. double displacement reaction
  4. D. combination reaction
Show answer and solution

Answer: (B) displacement reaction

Zinc is more reactive than copper, so it displaces copper from its salt: Zn + CuSO4 gives ZnSO4 + Cu. The reddish-brown deposit is copper metal. In double displacement two compounds exchange ions, a precipitate normally forms, and this is the common confusion. Only one element is replaced here.
Report a mistake

Original question written in the NDA 2018 GAT pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake