A mixture of krypton and oxygen gases, in a 6.92 L flask at 34 °C, contains 26.4 grams of krypton and 6.16 grams of oxygen. The partial pressure of oxygen in the flask is
atm and the total pressure in the flask is
atm.
To find the partial pressure of oxygen, we first need to calculate the moles of each gas present in the mixture.
1. Calculate the moles of krypton:
molar mass of krypton (Kr) = 83.80 g/mol
moles of krypton = mass of krypton / molar mass of krypton
moles of krypton = 26.4 g / 83.80 g/mol
moles of krypton = 0.315 mol
2. Calculate the moles of oxygen:
molar mass of oxygen (O2) = 32.00 g/mol
moles of oxygen = mass of oxygen / molar mass of oxygen
moles of oxygen = 6.16 g / 32.00 g/mol
moles of oxygen = 0.193 mol
3. Calculate the total moles of gas in the mixture:
total moles = moles of krypton + moles of oxygen
total moles = 0.315 mol + 0.193 mol
total moles = 0.508 mol
4. Now, we can calculate the mole fraction of oxygen:
mole fraction of oxygen = moles of oxygen / total moles
mole fraction of oxygen = 0.193 mol / 0.508 mol
mole fraction of oxygen = 0.380
5. Finally, we can find the partial pressure of oxygen using the mole fraction and total pressure:
partial pressure of oxygen = mole fraction of oxygen * total pressure
partial pressure of oxygen = 0.380 * X atm
Given that total pressure is X atm, we need to find the value of X.
Using the ideal gas law:
PV = nRT
X atm * 6.92 L = 0.508 mol * 0.0821 atm*L/mol*K * 34 + 0.508 mol * 0.0821 atm*L/mol*K * 273
X * 6.92 = 0.508 * 0.0821 * (34 + 273)
X * 6.92 = 19.84
X = 19.84 / 6.92
X = 2.87 atm
Therefore, the partial pressure of oxygen in the flask is:
partial pressure of oxygen = 0.380 * 2.87 atm
partial pressure of oxygen = 1.09 atm
The total pressure in the flask is 2.87 atm.