Answer:
Partial pressure of Ar = 4.7 atm
Step-by-step explanation:
Total pressure of a mixture of gases = Sum of partial pressure of each gas
This mixture contains: O₂, He and Ar.
Total pressure = 15.3 atm
Total pressure = Partial pressure O₂ + Partial pressure of He + Partial pressure of Ar
15.3 atm = 7.4 atm + 3.2 atm + Partial pressure of Ar
Partial pressure of Ar = 15.3 atm - 7.4 atm - 3.2 atm
Partial pressure of Ar = 4.7 atm