Question

Mixture of helium and oxygen can be used in scuba diving tanks to help prevent the bends , for a particulr dive 46L of He and 12L of O2 both at 25 degrees Celsius and 1.0 atm were pumped into a tank with a volume of 5.0L . Calculate the partial pressure of each gas and the total pressure in the tank at 25 degrees Celsius

Answer 1

To calculate the partial pressure of each gas, we first need to find the moles of each gas by using the ideal gas law equation:

PV = nRT

Where:
P = pressure of the gas
V = volume of the gas
n = number of moles of the gas
R = ideal gas constant (0.0821 L.atm/mol.K)
T = temperature in Kelvin

For helium:
P(He) = n(He) * R * T / V
P(He) = (46L * 1 atm) * 0.0821 L.atm/mol.K * (25 + 273) K / 5.0 L
P(He) = 48.418 atm

For oxygen:
P(O2) = n(O2) * R * T / V
P(O2) = (12L * 1 atm) * 0.0821 L.atm/mol.K * (25 + 273) K / 5.0 L
P(O2) = 12.105 atm

To find the total pressure in the tank, simply add the partial pressures of both gases:

Total pressure = P(He) + P(O2)
Total pressure = 48.418 atm + 12.105 atm
Total pressure = 60.523 atm

Therefore, the partial pressure of helium is 48.418 atm, the partial pressure of oxygen is 12.105 atm, and the total pressure in the tank is 60.523 atm.