Answer: The total pressure of the mixture is 2.76 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.

Given :
=total pressure of gases = ?
= partial pressure of oxygen = 0.00461 atm
= partial pressure of nitrogen = 1.78 atm
= partial pressure of argon = 0.975 atm
putting in the values we get:
Thus the total pressure of the mixture is 2.76 atm