An ideal gas composed of helium atoms is at a pressure of 2.00 atmospheres and a temperature of 35.0°C. What is the mass density? (He = 4.00 u)

Question

Quizplus · Accepted Answer

The mass density of an ideal gas can be calculated using the formula:
ρ = (P * M) / (R * T)
Where:
P = pressure
M = molar mass
R = gas constant
T = temperature

For helium, M = 4.00 g/mol or 4.00 * 10^-3 kg/mol
R = 8.31 J/mol·K
P = 2.00 atm = 2.02 * 10^5 Pa (using conversion factor of 1 atm = 1.01325 * 10^5 Pa)
T = (35.0 + 273.15) K = 308.15 K

Substituting the values into the formula, we get:
ρ = (2.02 * 10^5 Pa * 4.00 * 10^-3 kg/mol) / (8.31 J/mol·K * 308.15 K)
ρ = 0.316 kg/m3

Therefore, the mass density of the gas is 0.316 kg/m3, which is closest to choice D (0.316 kg/m3).

An Ideal Gas Composed of Helium Atoms Is at a Pressure