18 g of argon occupy 750 ml at a particular temperature and pressure. How many grams of methane would occupy the same volume at the same temperature and pressure?

7.21 grams is the mass of methane

Explanation:

We may use the Ideal Gases Equation to solve this:

P. V = n. R. T

Let's determine the moles of Ar

18 g. 1 mol / 39.9 g = 0.451 mol

In both situations, volume, temperature and pressure are the same so the moles of methane will also be the same as Argon's.

Let's convert the moles to mass of CH4.

0.451 mol. 16g/1mol = 7.21 grams