Question

38. Change of colour can indicate both physical and chemical changes. Which
kind of change does this experiment signify and why?
Iron nail
Cu deposits
on the iron
nail
CuSo solution
FeSO solution
a) Physical change as the nail only changes colour on the surface not the whole.
b) Chemical change due to deposition of a new substance on the nail
c) Chemical change as the colour change is irreversible.
Both b and care correct.​

Answer 1

When an iron nail immersed in the solution of copper sulphate than iron displaces copper from the solution of copper sulphate because iron is more reactive than copper. Therefore copper sulphate solution colour changes from blue to pale green