Answer:
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
