A sample of neon at 30.5°C exerts a pressure of 701 mm Hg? What is its density?

Question

Quizplus · Accepted Answer

Using the Ideal Gas Law: PV = nRT, we can rearrange for density: 
d = (PM) / RT 
where P is pressure, M is molar mass, R is the gas constant, and T is temperature in Kelvin. 
Since we are given pressure and temperature, we need to find the molar mass of neon which is 20.18 g/mol. 
Converting the temperature into Kelvin (30.5 + 273.15 = 303.65 K), we can plug in the values: 
d = (701 mmHg)(20.18 g/mol) / (0.08206 L atm/mol K)(303.65 K) 
d = 0.747 g/mL

A Sample of Neon at 30