Question

A brown coloured copper powder was placed in a china dish and was strongly

heated in air when a compound ‘X’ is formed. The compound ‘X’ was insoluble in water but dissolved in dilute hydrochloric acid forming a greenish solution

without evolution of any gas. Try to answer the following questions based on

the observations.

a) What is chemical formula and colour of compound X?

b) Give chemical equation and category of the reaction involved.

c) How X forms green coloured solution?

d) Suggest method to get copper powder back from X.​

Answer 1

Answer:

X is copper (Cu) and the black-coloured compound formed is copper oxide (CuO). The equation of the reaction involved on heating copper in given below.

2Cu+O

2

→2CuO.