Question

how many molecules does 20.0 L of nitogen contain

Answer 1

i think your question is missing some info?

Answer 2

all it gave me

Answer 3

If we assume that the gas is at STP, 1 mol of gas =22.4L. Convert to moles, then use avogadro's number to find molecules.

Answer 4

Lacking any information to the contrary, supposing the volume measurement to be made at STP:
(20.0 L) / (22.414 L/mol) × (6.022 × 10^23 molecules /mol) =
5.37 × 10^23 molecules N2