Question

In a sample of air at STP, the partial pressure of nitrogen gas is PN, = 0.78 atm and the partial

pressure of argon gas is Par = 0:01 atm. Calculate the partial pressure of oxygen gas Po, at STP.
Ignore units and use the proper amount of significant figures.

Answer 1

0.21 atm

Step-by-step explanation:

Step 1: Given data

• Pressure of air (P): 1 atm (standard pressure)

• Partial pressure of nitrogen (pN₂): 0.78 atm

• Partial pressure of argon (pAr): 0.01 atm

Step 2: Calculate the partial pressure of oxygen

The air is a gaseous mixture formed mainly by nitrogen, oxygen and argon. The total pressure is equal to the sum of the partial pressures of the gases.

P = pN₂ + pAr + pO₂

pO₂ = P - pN₂ - pAr

pO₂ = 1 atm - 0.78 atm - 0.01 atm

pO₂ = 0.21 atm