A deep-sea diver uses a gas cylinder with a volume of 13.0 L and a content of 50.1 g of O2 and 33.4 g of He. Calculate the partial pressure of each gas and the total pressure if the temperature of the gas is 22°C.

I got PO= 5.82, PHe=15.5 and Ptotal=21.4 but it says that PO and Ptotatl are wrong, can anyone help?

Your bottle contains 1.57 moles of O2 and 8.35 moles of He, for a total of 9.92 moles. At STP, that gas would occupy 222 liters; at 22 C and 1 atm, it would occupy 240 liters. Since the vlume is 13.0 L, the pressure must be Ptotal = 240/13 = 18.8 atm

The partial pressure of O2 is 15.9% of the total pressure, or 2.98 atm

Your mistake may be in using 16 instead of 32 for the (molecular) weight of oxygen.

To calculate the partial pressure of each gas and the total pressure, we need to use the ideal gas law and Dalton's law of partial pressures.

1. Convert the given temperature from Celsius to Kelvin. Add 273 to the temperature (22 + 273 = 295 K).

2. Calculate the number of moles of each gas using the ideal gas law equation:
PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin.

For oxygen (O2):
nO2 = (mass of O2 / molar mass of O2)
= (50.1 g / 32.0 g/mol)
= 1.57 mol

For helium (He):
nHe = (mass of He / molar mass of He)
= (33.4 g / 4.00 g/mol)
= 8.35 mol

3. Calculate the partial pressure of each gas using Dalton's law of partial pressures. According to Dalton's law, the total pressure is the sum of the partial pressures of each gas.
PO2 = (nO2 * R * T) / V
and
PHe = (nHe * R * T) / V

For oxygen:
PO2 = (1.57 mol * 0.0821 L·atm/(mol·K) * 295 K) / 13.0 L
= 3.55 atm

For helium:
PHe = (8.35 mol * 0.0821 L·atm/(mol·K) * 295 K) / 13.0 L
= 15.4 atm

4. Calculate the total pressure by summing up the partial pressures:
Ptotal = PO2 + PHe
= 3.55 atm + 15.4 atm
= 18.95 atm

Therefore, the correct partial pressure of oxygen (PO2) is approximately 3.55 atm, the partial pressure of helium (PHe) is approximately 15.4 atm, and the total pressure (Ptotal) is approximately 18.95 atm.