Question

A reddish brown vessel developed a green coloured solid 'X' upon exposure to air. The vessel upon reacting with dilute sulphuric acid forms a blue coloured solution and a gas 'Y'. 'X' decomposes to form black oxide 'Z' of the reddish brown metal and gas 'Y'. Identity and name X, Y and Z. Write the chemical equations for the reactions involved. Also identify the type of reaction.

Answer 1

X=copper
Y=hydrogen
Z=copper oxide
Cu+H2SO4------->CuSO4+H2
CuSO4-------∆----->CuO
this is decomposition reaction

Answer 2

X - Copper  metal (Cu)

Y - Hydrogen  gas (H₂)

Z - Copper Oxide  (CuO)

Cu + H₂SO₄  ------->  CuSO₄ + H₂

CuSO₄ ------------>CuO  + SO₂

This is a decomosition reaction