Question

What is the mass in kg of 35.6 moles of methane gas?

Answer 1

The mass of Methane gas (CH4) in kg is .571kg. You multiply the number of moles of CH4 by the atomic mass of CH4 to get you answer in grams. Then, you divide the answer by 1000 to get your answer into kilograms. <span />

Answer 2

Answer:

The mass of 35.6 moles of methane gas is 0.5696 kg.

Explanation:

To solve the problem we need to start calculating the mass of 1 mole of methane (CH₄).

1st) Find the Molecular weight (Molar mass) of methane

Methane has 1 carbon atom and 4 hydrogen atoms, so we need to look for the atomic weight of these elemnts in the periodic table, and multiply them by the number of atoms in the molecule:

Carbon atomic weight + (4.Hydrogen atomic weight) = Methane molar mass

12 g/mol + (4.1 g/mol) = 16 g/mol

Up to here, we found the molar mass of methane, that means that 1 mol of methane weights 16 g.

2nd) Find the weight of 35.6 moles of methane

We can solve this by using the "Rule of three" thinking that if 1 mole of methane weighs 16 g, the 35.6 moles will weight "x" grams. The Rule of three is:

         1 mol of methane ------------ 16 g

35.6 moles of methane ------------ x = (35.6 moles . 16 g)/ 1mol = 569.6 g

So, 35.6 moles of methane weight 569.6 g.

3rd) Convert the grams into kilograms

The relation between gram and kilogram is that 1000 g are equal to 1kg, so let's use this relation in a Rule of three:

1000 g ---------- 1 kg

569.6 g ---------- x = (569.6 g . 1 kg)/1000 g = 0.5696 kg

Finally, the mass of 35.6 moles of methane gas is 0.5696 kg.

Another option:

You can convert the 16g into kg first and you will reach the same final result.