Answer:
0.158g/L.
Explanation:
MM of helium gas or He =4 g/mol
P = 0.974 atm
T = 27 °C, but we need absolute temperature.
TK = TC + 273
T = 27 + 273 = 300 K
m/V = (4 g/mol · 0.975 atm) / (0.0821 L·atm/mol·K · 300 K)
m/V = 0.975/6.1575 g/L
m/V = 0.158g/L
Answer: The density of the helium is 0.158g/L.
