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

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.  

the answer is   c.) 1575 j.

explanation: