Question

Commercial scuba divers use tanks filled with a mixture of gases known as Trimix on very long, deep dives. Trimix is composed of 70% nitrogen, 10% oxygen and 20% helium. The total pressure of the Trimix inside a certain tank at the beginning of the dive is 118.4 atm. A. What is the partial pressure of the oxygen in the tank?

Answer 1

Answer:

Partial pressure of O = 11.84 atm

Explanation:

To solve the excersise we think in the partial pressure law with mole fraction.

Mole fraction of gas = Partial pressure of gas / Total pressure

We have data of all the mole fractions:

• 0.70 N

• 0.10 O

• 0.20 H

Let's find out the partial pressure of oxygen in the tank. We replace data in the formula:

0.10 = Partial pressure of gas / 118.4 atm

0.10 . 118.4 atm = Partial pressure of gas → 11.84 atm

If we determine all the partial pressures:

0.70 . 118.4 atm = 82.88 atm → Partial pressure N

0.20 . 118.4 atm = 23.68 atm → Partial pressure He

We can determine the partial pressure of the trimix.

Sum of partial pressures of each gas = Total pressure of the mix

11.84 atm + 82.88 atm + 23.68 atm = 118.4 atm

(A way to see, if our operations were ok)