Write one equation each for the decomposition reactions where energy is supplied in the form of (a) heat, (b) light, and(c) electricity.

11 What type of chemical reaction is used to extract metals from their naturally occurring compounds like oxides or chlorides? 12 Name two anti-oxidants which are usually added to fat and oil containing foods to prevent rancidity. 14 In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the chemical equation of the reaction involved. 16 What type of reactions are represented by the following equations ?

(i) CaC0₃CaO + CO₂

(ii) CaO + H₂OCa(OH)₂

(iii) 2FeSO₄Fe₂O₃ + SO₂ + SO₃

(iv) NH₄CINH₃ + HCl

(v) 2Ca + O₂2CaO