Question

A is a reddish-brown metal, which combines with O₂ at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B, and C with reaction.

Answer 1

(A) is a reddish-brown metal – Copper

\[\ce{2Cu + O2 ->[<1370K]\underset{\text{Cupric Oxide (Black)}}{2CuO(B)}}\]

\[\ce{4Cu + O2 ->[>1370K]\underset{\text{Cuprous oxide (Red)}}{2Cu2O(C)}}\]

A – Copper; B – Cupric oxide; C – Cuprous oxide.