JEE Main · 2022 · Shift-IeasyDNF-066

Dihydrogen reacts with CuO to give:

d & f-Block Elements · Class 12 · JEE Main Previous Year Question

Question

Dihydrogen reacts with CuO to give:

Options
  1. a

    Cu(OH)2\text{Cu(OH)}_2

  2. b

    Cu(s)\text{Cu}(s)

  3. c

    Cu2O\text{Cu}_2\text{O}

  4. d

    CuH2\text{CuH}_2

Correct Answerb

Cu(s)\text{Cu}(s)

Detailed Solution

Reaction of H2\text{H}_2 with CuO:

CuO+H2ΔCu+H2O\text{CuO} + \text{H}_2 \xrightarrow{\Delta} \text{Cu} + \text{H}_2\text{O}

Analysis:

  • H2\text{H}_2 is a reducing agent — it reduces CuO
  • Cu²⁺ in CuO is reduced to Cu(0) (metallic copper)
  • H2\text{H}_2 is oxidised to H2O\text{H}_2\text{O}

This is a classic reduction of metal oxide reaction. The black CuO is converted to reddish-brown metallic copper.

Why not Cu₂O? The reduction goes all the way to Cu(0) because H₂ is a strong enough reducing agent.

Answer: Option (2) — Cu(s)

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Dihydrogen reacts with CuO to give: (JEE Main 2022) | Canvas Classes