The volume of a sample of methane collected over water at 40C and 735 torr is measured to be 425 mL. How many moles of methane is present?

Question

anonymous · Answer

I thought I had to use the mole fraction equation but I tried that...and I'm obviously missing something lol.

anonymous · Answer

did you try using ideal gas law
pV=nRT -> n = pV/RT
just watch out for units!!!

anonymous · Answer

$$n=\frac{ 55.40mmHg(425mL) }{ 0.08206L-atm(40C) }$$

anonymous · Answer

So like this?

anonymous · Answer

no, not like that, i told you to mid the units! pressure must be in Pa, volume in m3, temperature in K, constant in 8,314 J/mol K

abb0t · Answer

Make sure you're using the correct $R$ constant that match with YOUR units. There are more than a few with variable units. Look here: