Write the balanced chemical equation for the following and identify the type of reaction in each case.

(a) Potassium bromide (aq) + Barium iodide (aq) ⟶ Potassium iodide (aq) + Barium bromide (s)

(b) Zinc carbonate (s) ⟶ Zinc oxide (s) + Carbon dioxide (g)

(c) Hydrogen (g) + Chlorine(g) ⟶ Hydrogen chloride (g)

(d) Magnesium (s) + Hydrochloric acid (aq) ⟶ Magnesium chloride (aq) + Hydrogen(g)

What does one mean by exothermic and endothermic reactions? Give examples?

Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions?

Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.