Can someone please help me with a chemistry problem?

Question

Given CH4+4S --> CS2+ 2H2S, what is the theoretical yield of carbon disulfide when 160. grams of methane is reacted with an equal mass of sulfur?

also, can you explain how. please? thank you!

isn't sulfur the limiting reactant?

i always get 23.7 grams as the answer, but it's not right.

Answer 1

This is a simple mol conversion. 160 grams of methane is equal to 10 mols and 10 mols of carbon disulfide is approximately 760 grams

Answer 2

This problem is called "stoichiometry". The key is that molecules react together based on molecules in a balanced equation. This translates into moles.

You already have the balanced equation. 1 mole of CH4 will yield 1 mole of CS2.

Convert the 160 g of methane to moles. That tells you how many moles of CS2 are produced. You can convert that to grams based on the molecular mass of CS2.

But you are not done. You need to see if you have enough sulfur, otherwise the reaction will stop when the limiting reactant is used up.

You need 4 moles of sulfur to produce 1 mole of CS2. Convert the 160 g of sulfur to moles and divide by 4. That is the amount (moles) of CS2 that you can produce based on the sulfur quantity available.

The samller of the two calculations above is the answer.

Answer 3

One mole of CH4 results in one mole of CS2.

CH4: 160 g/16 g/mol = 10 mol

CS2: 10 mol * 78 g/mol = 780 g