Answer:
0.21 atm
Step-by-step explanation:
From the question given above, the following data were obtained:
Partial pressure of N₂ (P₁) = 0.78 atm
Partial pressure of Ar (P₂) = 0.01 atm
Partial pressure of O₂ (P₃) =?
Since the system is at standard temperature and pressure (STP), the total pressure of the system is 1 atm.
Finally, we shall determine the partial pressure of O₂. This can be obtained as follow:
Partial pressure of N₂ (P₁) = 0.78 atm
Partial pressure of Ar (P₂) = 0.01 atm
Total pressure (Pₜ) = 1 atm
Partial pressure of O₂ (P₃) =?
Pₜ = P₁ + P₂ + P₃
1 = 0.78 + 0.01 + P₃
1 = 0.79 + P₃
Collect like terms
1 – 0.79 = P₃
P₃ = 0.21 atm
Therefore, the partial pressure of O₂ is 0.21 atm.