What happens when sodium sulphate is mixed with barium chloride?

Give an example of a combination reaction?

What is the difference between the burning of Mg ribbon in air and Heating of Ferrous sulphate crystals? Write the reaction?

There are three salts of color having color green, blue and white crystalline solid is given to you, Name the salts?

What will happen if you dissolve calcium oxide in water? Give reaction.