Question

When hydrochloric acid was added to copper sulphide, a vigrous
reaction took place. After whole of the compound reacted the
solution turned .......
...... with the liberation of gas with as
offensive .............. smell.
The Chemical equation is​

Answer 1

the solution turned light brown due to formation of cucl2 with the liberation of h2s or hydrogen sulphide gas which has a smell of rotting eggs
CuS+2HCl = CuCl2 + H2S...
hope this would help....