Why does the blue colour of copper sulphate solution fade on adding iron fillings ?

Give an example of:

(a) Single displacement reaction

(b) Double displacement reaction

(c) Photochemical reaction

(d) Thermal decomposition reaction

(e) Electrolytic decomposition reaction

(f) Combination reaction between two compounds ?

Give an example of each of the following chemical changes.

(a) A reaction involving

(i) change of state

(ii) formation of a precipitate

(b) An exothermic and an endothermic reaction involving carbon as one of the reactants.

(c) A reaction where colour change is noticed.

What is a chemical change? Give two examples of a chemical change?