Previous Year Question
Which of the following reactions is the metal displacement reaction? Choose the right option.
A.
A. 2Pb(NO3)2 → 2PbO + 4NO2 + O2↑
B.
B. 2KClO3 —Δ→ 2KCl + 3O2
C.
C. Cr2O3 + 2Al —Δ→ Al2O3 + 2Cr
D.
D. Fe + 2HCl → FeCl2 + H2↑
Correct Answer: C
Detailed Solution
Cr2O3 + 2Al → Al2O3 + 2Cr is a metal displacement reaction. Aluminium is more reactive than chromium, so it displaces chromium from chromium(III) oxide. This thermite reaction is also a redox reaction.