Question
The table below shows the percentage composition by volume of inhaled and exhaled air.
(a) By what percentage is:-
(i) Carbon dioxide concentration in exhaled air higher than inhaled air?
(ii) Oxygen concentration in the exhaled air lower than the inhaled air?
(b)Explain the difference in the composition of the gases between inhaled and exhaled air.
| Gas | Inhaled air(%) | Exhaled air(%) |
|---|---|---|
| Oxygen | 21 | 16 |
| Carbon (iv) oxide | 0.04 | 4.0 |
| Nitrogen | 78 | 78 |
(a) By what percentage is:-
(i) Carbon dioxide concentration in exhaled air higher than inhaled air?
(ii) Oxygen concentration in the exhaled air lower than the inhaled air?
(b)Explain the difference in the composition of the gases between inhaled and exhaled air.
Answer
(a)(i) 4% - 0.04% = 3.96%
(ii) 21% - 4% = 17%
(b) - Inhaled air has a higher concentration (%) of oxygen than exhaled air.Some of the oxygen is used for respiration.
- Inhaled air has a lower concentration or percentage of carbon(IV) oxide than exhaled air. Carbon(IV) oxide is produced in respiration.
- The concentration of nitrogen is the same in both inhaled and exhaled air. Nitrogen does not play any part in gaseous exchange and so its concentration does not change.
(ii) 21% - 4% = 17%
(b) - Inhaled air has a higher concentration (%) of oxygen than exhaled air.Some of the oxygen is used for respiration.
- Inhaled air has a lower concentration or percentage of carbon(IV) oxide than exhaled air. Carbon(IV) oxide is produced in respiration.
- The concentration of nitrogen is the same in both inhaled and exhaled air. Nitrogen does not play any part in gaseous exchange and so its concentration does not change.
Related Topics