Question

A sample of the gas at a pressure of 727 mmHg and a temperature of 18°C weighs 0.289

Answer 1

is that the complete question?

Answer 2

yeah thought so

Answer 3

I think this might be it

Answer 4

Anyway, Use PV = nRT to find moles of gas. I would recommend converting to L, atm, and K in order to use the ideal gas constant 0.0821 L atm / molK. Once you have the moles, divide mass/moles to get the molar mass. From there, try to come up with a formula with N and O that is close to the calculated molar mass.