What is the difference between displacement and double displacement reaction? Write equations for these reactions? (AS1)

Name the reactions taking place in the presence of sunlight? (AS1)

Why does respiration considered as an exothermic reaction? Explain. (AS1)

MnO₂ + 4HCl MnCl₂ + 2H₂O + Cl₂

In the above equation, name the compound which is oxidized and which is reduced? (A S1)

Give two examples for oxidation-reduction reaction. (AS1)