# Problem: Suppose you are given two 1-L flasks and told that one contains a gas of molar mass 30, the other a gas of molar mass 60, both at the same temperature. The pressure in flask A is X atm, and the mass of gas in the flask is 1.2 g . The pressure in flask B is 0.5X atm, and the mass of gas in that flask is 1.2 g .Which flask contains gas of molar mass 30, and which contains the gas of molar mass 60?

###### FREE Expert Solution
• We can establish a relationship between moles of the gases to their P and V using the ideal gas equation
• Since T and R are constant, we can say that

PV = n

• Flask A will appear as PV = n:

n = X*n

• Flask B will appear as:

n = 0.5X*n

87% (240 ratings) ###### Problem Details

Suppose you are given two 1-L flasks and told that one contains a gas of molar mass 30, the other a gas of molar mass 60, both at the same temperature. The pressure in flask A is X atm, and the mass of gas in the flask is 1.2 g . The pressure in flask B is 0.5X atm, and the mass of gas in that flask is 1.2 g .

Which flask contains gas of molar mass 30, and which contains the gas of molar mass 60?