Which contains more moles of material: 80 grams of helium gas (He,having atomic weight 4.0 g/mol)or 400 grams of argon gas (Ar,having atomic weight 40 g/mol)?
A) helium
B) argon
C) Both contain the same number of moles.

Question

Quizplus · Accepted Answer

Helium has a molar mass of 4.0 g/mol, so 80 grams of helium is 20 moles (80g / 4.0g/mol). Argon has a molar mass of 40 g/mol, so 400 grams of argon is 10 moles (400g / 40g/mol). Therefore, helium has more moles.

Which Contains More Moles of Material: 80 Grams of Helium