The mass of 1 liter of gas under normal conditions is 2.144 g. Determine the molar mass of the gas and its air density.

Given: 1 liter of gas.
Normal conditions (n.a.):
m (gas) = 2.144 g;
Find: M (gas) -?
D (air) -?
Decision:
1. By the condition of the problem, it is known – 1 mol of gas.
Y (gas) = m / M;
Y (gas) = 1 mol.
2. Find the molar mass:
M (gas) = m / Y = 2.144 / 1 = 2.144 g;
M (H2) = 2.144 g / mol, which means the gaseous substance is hydrogen. (data from the table of the Periodic Law).
3. Let’s calculate the value of density by air:
M (air) = 29 g / mol;
D (air) = M (H2) / M (air) = 2/29 = 0.68.
Answer: The relative density of hydrogen in air is 0.68.