2. What is the mass of 16.3 L of helium gas?

(16.3 L) / (22.414 L/mol) x (4.0026 g He/mol) = 2.91 g

mass = 2.91 grams

Explanation:

Base on Avogadro's law, At standard temperature and pressure the molar volume is the same for an ideal gas. Base on this practical principle the molar volume of gases is 22.4 dm³ per mol.

Since the molar mass of 1 mol of helium is 4.002602, this simply means the molar volume which is 22.4 dm³ = 4.002602.

Convert dm³ to liter,

1 dm³ (cubic decimeter) = 1 liter

22.4 dm³ = 22.4 liter

Therefore,

if 22.4 = 4.002602

16. 3 = mass of the helium gas

cross multiply

mass = 16.3 * 4.002602/22.4

mass = 65.2424126/22.4

mass = 2.91260770536 grams

mass = 2.91 grams