A heliox deep-sea diving mixture contains 2.0 gg of oxygen to every 98.0 gg of helium. What is the partial pressure of oxygen when this mixture is delivered at a total pressure of 8.0 atm?

The correct answer is 0.020 atm.

Explanation:

Partial pressure is calculated by using the formula,

Partial pressure = Mole fraction × Total pressure

The partial pressure of oxygen in a mixture can be calculated by using the formula,  

Mole fraction of oxygen in mixture = Number of moles of oxygen / No. of moles of oxygen + No. of moles of Helium

(1 gg or gigagram is equal to 10⁹ grams)

= 2 × 10⁹/32 /2 × 10⁹/32 + 98 × 10⁹ / 4

= 2.54 × 10⁻³

Now the partial pressure of oxygen = Mole fraction of oxygen × Total pressure of oxygen

= 2.54 × 10⁻³ × 8.0 atm

= 0.02032 atm

= 0.020 atm

the answer

explanation:

the capillary tube was too close to the bottom of the beaker.

the ruler may have moved.

water got into the capillary tube.

the temperature was not allowed to equilibrate in the 2-4 minutes.

the volume increases