Question

Assume a scuba diver is working at a depth where the total pressure is 5.0 atm (about 50 m below the surface). What mole fraction of oxygen is necessary in order for the partial pressure of oxygen in the gas mixture the diver breathes to be 0.210 atm?

Answer 1

Answer: 0.042

Explanation:

The partial pressure of a gas is given by Raoult's law, which is:

$p=p_T\times \chi$

where,

$p_A$ = partial pressure of oxygen = 0.210 atm

$p_T$ = total pressure = 5.0 atm

$\chi_A$ = mole fraction of oxygen = ?

Putting values in above equation, we get:

$0.210=5.0\times \chi$

$\chi =0.042$

Hence, the mole fraction of oxygen necessary in order for the partial pressure of oxygen in the gas mixture the diver breathes to be 0.210 atm is 0.042.