Which of the following is/are example(s) of exothermic reaction? (i) Making of slaked lime (ii) Burning of natural gas (iii) Respiration

All three reactions are examples of exothermic reactions. Making of slaked lime involves calcium oxide reacting with water, releasing heat. Burning natural gas involves methane reacting with oxygen, producing carbon dioxide, water, and heat. Respiration is also exothermic, as glucose reacts with oxygen in cells to produce carbon dioxide, water, and release energy.