(a(i))[1]
Using the data in Table 5.1, calculate how much water is lost each day in exhaled air.
(a(ii))[2]
Explain why water is present in exhaled air.
(b)[3]
Explain why, although $2.25~\text{dm}^3$ of water enter through the mouth, the faeces contain only $0.10~\text{dm}^3$ of water.
(c)[2]
Explain the role of water in urine.
(d)[1]
The gap between a person’s water intake and water loss is explained by water made during a metabolic reaction in the body. Name this metabolic reaction.