A sample of helium occupies 44.8 L at standard temperature and pressure (0°C and 1 atm). What is the mass of the sample? The atomic mass of helium is 4.00 u.
A) 2.00 g
B) 4.00 g
C) 8.00 g
D) 16.0 g

Question

Quizplus · Accepted Answer

At standard temperature and pressure (STP), 1 mole of any ideal gas occupies 22.4 L. Therefore, 44.8 L of helium is 2 moles (44.8 L / 22.4 L/mol = 2 mol). Since the atomic mass of helium is 4.00 u, the mass of 2 moles of helium is 2 mol * 4.00 g/mol = 8.00 g.

A Sample of Helium Occupies 44