a. Magnesium Burns in oxygen.
--⟩it produces light bright enough to blind you temporarily.
b. Calcium carbonate is heated.
--⟩ form calcium oxide and evolve carbon dioxide gas.
c. Hydrogen reacts with nitrogen at necessary condition.
----⟩some of the hydrogen and nitrogen will react to form ammonia.
d. potassium hydroxide reacts with nitric acid.
---⟩When potassium reacts with nitric acid then, potassium displace hydrogen from its solution and becomes colorless liquid.
e. Carbon dioxide is treated with limewater.
---⟩to form a white precipitate (appears milky) of calcium carbonate, CaCO 3.
Hope it is helpful to you