Determine the volume (in L) of 8.00 g of He gas at 25.0 °C and 770. 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
what is the correct answer
To determine the volume of the gas, we can use the Ideal Gas Law equation:
PV = nRT
Where:
P = pressure = 770. mmHg = 770. mmHg * (1 atm / 760 mmHg) = 1.01316 atm
V = volume
n = moles of gas
R = ideal gas constant = 0.0821 L.atm/mol.K
T = temperature = 25.0 °C = 25.0 + 273.15 = 298.15 K
First, we need to calculate the number of moles of helium gas:
n = m/M
n = 8.00 g / 4.0026 g/mol = 1.9996 mol
Now, we can substitute the values into the Ideal Gas Law equation and solve for V:
(1.01316 atm) * V = (1.9996 mol) * (0.0821 L.atm/mol.K) * (298.15 K)
V = (1.9996 * 0.0821 * 298.15) / 1.01316
V = 49.9472 L
Therefore, the volume of 8.00 g of He gas at 25.0 °C and 770. mmHg is 49.9472 L, which should be rounded to 50 L with only two significant figures.