Two identical pressure cylinders show the same pressure on the gauge. They both are at room temperature. One contains methane (CH4) and the other contains Nitrogen (N2). Use what you know about gas laws to explain how to tell which is by weighing the cylinders.
My problem is set up like this:
P1 V1/N1 T1 and P2 V2 / N2 T2
Look at their molecular weight and then tell me how you would tell. You can use the periodic table.
To determine which cylinder contains methane (CH4) and which one contains Nitrogen (N2) based on their weights, we need to consider their molecular weights or molar masses.
The molecular weight of methane (CH4) is calculated as:
(1 * atomic weight of C) + (4 * atomic weight of H)
= (1 * 12.01 g/mol) + (4 * 1.01 g/mol)
= 12.01 g/mol + 4.04 g/mol
= 16.05 g/mol
The molecular weight of nitrogen (N2) is calculated as:
(2 * atomic weight of N)
= (2 * 14.01 g/mol)
= 28.02 g/mol
From the molecular weights, we can see that methane has a molecular weight of 16.05 g/mol, while nitrogen has a molecular weight of 28.02 g/mol. This means that methane is lighter than nitrogen.
Using this information, we can determine which gas is contained in each cylinder by weighing them. The cylinder that weighs less would contain methane (CH4), and the heavier cylinder would contain Nitrogen (N2).