A closed container with a mixture of hydrogen, helium, and argon has a total pressure of 2.55 atm. The partial pressure of hydrogen is 0.700 atm and the partial pressure of argon is 705 mm Hg. What is the partial pressure of helium?

Dalton's law of partial pressures. The total is the sum of each.

ptotal = pH2 + pAr + pHe

Total pressure=partial pressure of mixture

Total pressure=partial pressure of Hydrogen +PHe+Pa
Partial pressure of Hydrogen= 0.700 atm
Total pressure=2.55
Partial pressure of AR= 705 mm, lets convert that to atm. 1 atm=760 mm Hg
705/760mm of Hg
705/760=partial pressure of AR= 0.92763158=0.92
2.55=0.700 atm +Partial Pressure of He +0.92
0.7+0.928=1.628
2.55= 1.628 + partial Pressure of He
subtract 1.628 from 2.55, 2.55-1.628=0.930
So the answer would be partial pressure of helium is 0.930 atm.

To find the partial pressure of helium, we need to convert the pressure of argon from mm Hg to atm. Then, we can subtract the partial pressures of hydrogen and argon from the total pressure to find the partial pressure of helium.

Step 1: Convert the pressure of argon from mm Hg to atm.
1 atm = 760 mm Hg (standard conversion factor)

705 mm Hg * (1 atm / 760 mm Hg) = 0.926 atm (approximately)

Step 2: Subtract the partial pressures of hydrogen and argon from the total pressure.
Total pressure - Partial pressure of hydrogen - Partial pressure of argon = Partial pressure of helium

2.55 atm - 0.700 atm - 0.926 atm = 0.924 atm (approximately)

Therefore, the partial pressure of helium is approximately 0.924 atm.