Question

The process of respiration is:
(a) an oxidation reaction which is endothermic
(b) a reduction reaction which is exothermic
(c) a combination reaction which is endothermic
(d) an oxidation reaction which is exothermic

Answer 1

(d) an oxidation reaction that is exothermic

The food that we eat breaks down into simple compounds during digestion. For example, potatoes, bread and rice, which contain carbohydrates, breaks down to give glucose. Glucose combines with oxygen to give energy, so it is a oxidation reaction because addition of oxygen takes place; since energy is released in this process, it is also an exothermic reaction.

The chemical reaction is given as follows:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy