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.

Answer 1

Converting temperature to kelvin,
T = 273 + 27 = 298 K

Using ideal gas equation,
PV = nRT
1.2 x 15.8 = n x 0.082 x 298
n = 0.776 moles.

Therefore mass of methane gas= moles x molar mass
= 0.776 x 16 = 12.416 grams.