What is the partial pressure of argon gas in a sealed vessel that has a total pressure of 1514 psi and partial pressures of 325 psi for oxygen and 649 psi for nitrogen?

The total pressure of a gas is equivalent to the sum of partial pressures of the individual components of the gas. Here, there are three gases, argon, oxygen and nitrogen. Therefore:

Total pressure = PP nitrogen + PP oxygen + PP argon

1,514 = 649 + 325 + PP Argon

The partial pressure of argon then works out to be 540 PSI.