Answer:
Mass = 20 g
Explanation:
Given data:
Number of moles of He = 5 mol
Mass of He = ?
Solution:
Formula:
Number of moles = mass/ molar mass
Molar mass = 4 g/mol
by putting values,
5 mol = Mass / 4 g/mol
Mass = 5 mol × 4 g/mol
Mass = 20 g
I don't know which one I should answer