11. Calculate the total pressure of a mixture of 0.02 mol He and 0.01 mol H2 in a 5.0 L flask at 10 ºC.
PV = nRT
n = total mols if you want total pressure.
n = mols of each if you want partial pressure of each gas by itself.
To calculate the total pressure of a mixture of gases, we can use the ideal gas law equation:
PV = nRT
Where:
P = Total pressure of the mixture (in atm)
V = Volume of the flask (in L)
n = Number of moles of gas
R = Ideal gas constant (0.0821 L*atm/(mol*K))
T = Temperature of the gas (in Kelvin)
First, we need to convert the temperature from Celsius to Kelvin:
T(K) = T(ºC) + 273.15
T(K) = 10 ºC + 273.15 = 283.15 K
Now, we can substitute the values into the ideal gas law equation for each gas and calculate their respective partial pressures.
For He:
n(He) = 0.02 mol
V = 5.0 L
R = 0.0821 L*atm/(mol*K)
T = 283.15 K
Using the ideal gas law equation for He:
P(He) = (0.02 mol)(0.0821 L*atm/(mol*K))(283.15 K) / (5.0 L)
P(He) = 0.9443 atm
For H2:
n(H2) = 0.01 mol
V = 5.0 L
R = 0.0821 L*atm/(mol*K)
T = 283.15 K
Using the ideal gas law equation for H2:
P(H2) = (0.01 mol)(0.0821 L*atm/(mol*K))(283.15 K) / (5.0 L)
P(H2) = 0.4712 atm
Finally, to find the total pressure of the mixture, we add the partial pressures of each gas:
P(total) = P(He) + P(H2)
P(total) = 0.9443 atm + 0.4712 atm
P(total) = 1.4155 atm
Therefore, the total pressure of the mixture of 0.02 mol He and 0.01 mol H2 in a 5.0 L flask at 10 ºC is approximately 1.42 atm.