Question

2 examples of with
a) evolution of gas
b)change in colour

Answer 1

Answer:

1. Reaction of dil. Sulphur acid with zinc granules.

H2SO4 + Zn - ZnSO4 + H2

2. White silver chloride turns grey in sunlight. This is due to decomposition of silver chloride into silver and chlorine by light.

2AgCl(s) -----(sunlight) 2Ag(s) + Cl2(g)

Answer 2

a) Reaction of zinc with hydrochloric acid produces hydrogen

b) Reaction of iron and copper sulphate solution, changes the colour of the solution from blue to green