Hey there!
N₂ has a density of 1.25 grams per liter.
We have 2.31 liters of N₂.
2.31 x 1.25 = 2.8875
We have 2.8875 grams of N₂.
Find molar mass of N₂:
N: 2 x 14
------------
28 g/mol
2.8875 ÷ 28 = 0.10
There is 0.10 mol of nitrogen in 2.31 L of N₂.
Hope this helps!
