To identify a diatomic gas (X2), a researcher carried out the following experiment: She weighed an empty 4.3-L bulb, then filled it with the gas at 1.90 atm and 21.0 C and weighed it again. The difference in mass was 9.5 g . Identify the gas.

Answer 1

Use PV = nRT and solve for n = number of mols, the n = grams/molar mass. You know grams and n, solve for molar mass.

Answer 2

N2