Question

Uppose you have two 1-L flasks, one containing a gas with a molar mass of 30 g and the other a gas with a molar mass of 60 g. Both flasks are at the same temperature, both gas samples have a mass of 1.2 g, but the pressure in Flask X is 1.0 atm and in Flask Y is 0.5 atm. Which flask contains the gas molar mass 30 g?
flask X
flask Y
not enough information problem.

Answer 1

Answer:

The answer to your question is: Flask X

Explanation:

Data

                            Flask X              Flask B

Molar mass            30 g                    60 g

mass                       1.2g                     1.2 g

Pressure                  1 atm                   0.5 atm

Formula                  PV = nRT

                         In the formula, we can notice that the number of moles (n)

                         is directly proportional to the pressure.

Then, let's calculate the number of moles

               flask X                                flask Y

  30 g  ---------------  1 mol           60 g -------------- 1 mol

  1.2 g ----------------   x                 1.2 g -------------   x

   x = (1.2 x 1) / 30                        x = (1.2 x 1) / 60

   x = 0.04 mol                             x = 0.02 mol

From the results, we conclude that the flask with the gas of molar mass 30g is the flask with pressure of 1 atm, because the higher the number of moles, the higher the pressure.