How many grams of methane gas (CH4) are in a 15.8 liter sample at 1.2 atmospheres and 27°C? Show all work used to solve this problem.

27'C- 300K
n= 1.2atm X 15.8l / 0.0821 X 300K
n= 0.77

0.77 moles X 16.0416 / 1mol= 20.83 g

Can someone tell me if this is correct?

Question

How many grams of methane gas (CH4) are in a 15.8 liter sample at 1.2 atmospheres and 27°C? Show all work used to solve this problem. 

27'C-> 300K
n= 1.2atm X 15.8l / 0.0821 X 300K
n= 0.77

0.77 moles X 16.0416 / 1mol= 20.83 g

Can someone tell me if this is correct?

aaronq · Answer

yeah, your steps are good.

anonymous · Answer

Is the final answer hundred proof? I always feel like I'm two steps off

aaronq · Answer

you must've multiplied wrong, I'm getting a total mass of 12.347478684531059992 g

anonymous · Answer

Gas calculations will be my demise

anonymous · Answer

Thank you though

aaronq · Answer

haha i always double check my answers, it's easy to press something wrong on the calculator

aaronq · Answer

no problem