Question

Assume that air is 21 % oxygen and 79% nitrogen by volume. If the barometer pressure is 740 mm.the partial pressure of oxygen is closest to which one of the following ?

• A. 155 mm
• B. 310 mm
• C. 580 mm
• D. 740 mm

Answer 1

Answer: (A)

155 mm

Answer 2

Partial pressures of $O_2$ = mole fraction of $O_2 \times$ total pressure. = $\left( \frac{21}{21 + 79} \right) \times$ 740 mm = 155 mm