posted by Dia B .
What is the mass of air in a 250-mL Erlenmeyer flask (actual volume is 267
mL) at a typical laboratory pressure of 715 torr and a temperature of 21˚C?
Assume air to be an ideal gas having an average molar mass of 29.0 g/mol.
Use PV = nRT and solve for n.
Then n = grams/molar mass.
You know n and molar mass, solve for grams.