pO2 pressure at sea level:

Ans. (c) 160* At sea level the atmosphere exerts a total pressure of 760mmHg. Since the atmosphere is 21% 02 (by volume), the partial pressure of oxygen (pO,)= 0.21 x 760 = 160 mmHg.* The partial pressure of C02 (pC02) at sea level is 0.23 mmHg.