Write down the balanced equation for the reaction when:
Carbon dioxide is passed through a suspension of lime stone in water.

Write down the balanced equation for the reaction when:
Potassium ferricyanide reacts with hydrogen peroxide in basic solution

Write down the balanced equation for the reaction when:
Carbon dioxide is passed through a concentrated aqueous solution of sodium chloride saturated with ammonia.

Give reasons of the following:
Magnesium oxide is used for the lining of steel making furnace.