A gaseous compound is 30.4% nitrogen and 69.6% oxygen by mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at -4.00°C. Which of these choices is its molecular formula?

Answer 1

The N:O ratio can be obtained by dividing the % mass by the respective atomic masses, namely
N:O = 30.4/14 : 69.6/16 = 2.17:4.35=1:2

Use the 5.25g sample and the ideal gas law to find the molecular mass and hence the composition.

Answer 2

* molar mass

Answer 3

NO2