Question

A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.

Answer 1

Copper is the metal which does not react with acids to liberate hydrogen gas. With oxygen, it forms Copper Oxide.
Hence, metal M is copper and the black coloured product is copper oxide.

`2"Cu"("s") + "O"_2("g") -> 2"CuO"("s")`