To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 2.7-L bulb, then filled it with the gas at 1.30atm and 30.0 ∘C and weighed it again. The difference in mass was 3.9g . Identify the gas.

Answer 1

PV = nRT and solve for n = number of mols.
Then n = grams/molar mass. You know n and grams, solve for molar mass. Identify the gas from that. Remember some gases are diatomic.

Answer 2

if it was 1.1 then its Nitrogen fam my bad.