answer and explanation
3.0 grams is converted to gas.
we first find the number of mols
n = m/M
n - mols
m - mass
M - molar mass
n = 3.0/ 28.01
= 0.12 mols
we know that at STP every gas has a volume of 22.4 L
therefor 0.12 mols will have a volume of:
0.12 x 22.4 = 2.69 L