i. When lead is added to copper sulphate solution, more reactive lead displaces less reactive copper from copper sulphate. The colourless lead sulphate solution is formed with evolution of heat.
ii. When potassium chromate solution is added to barium sulphate solution, yellow precipitate of barium chromate is formed.
iii. When calcium chloride solution is added to sodium carbonate solution, white precipitate of calcium carbonate is formed.
iv. When sodium chloride solution is mixed with silver nitrate solution, white precipitate or silver chloride is formed.
v. When dilute sulphuric acid is added to barium chloride solution, white precipitate of barium sulphate is rormed.