Determine the volume (in L) of 5.70 g of He gas at 25.0 °C and 740. mmHg. Be sure your answer has the correct number of significant figures.
Note: Reference the Fundamental constants and Conversion factors for non-SI units table for additional information.
L
10
To determine the volume of the gas, we can use the ideal gas law equation:
PV = nRT
where:
P = pressure = 740. mmHg = 740. mmHg * 1 atm / 760 mmHg = 0.974 atm
V = volume
n = moles of gas
R = ideal gas constant = 0.0821 L.atm/mol.K
T = temperature = 25 + 273 = 298 K
First, we need to calculate the moles of He gas:
molar mass of He = 4.00 g/mol
moles = mass / molar mass = 5.70 g / 4.00 g/mol = 1.425 mol
Now, we can substitute the values into the ideal gas law equation:
(0.974 atm) * V = (1.425 mol) * (0.0821 L.atm/mol.K) * (298 K)
V = (1.425 mol * 0.0821 L.atm/mol.K * 298 K) / 0.974 atm
V = 34.41 L
Therefore, the volume of 5.70 g of He gas at 25.0 °C and 740. mmHg is 34.41 L.