How much iron (II) sulfide would be needed to prepare 15L of hydrogen sulfide? My balanced equation is 2HCl + FeS --> H2S + FeCl2. I have converted 15L H2S to mols, but I have no idea where to go from here.

You're half way there IF the H2S is at STP. If not then an adjustment needs to be made.

But let me start over to make sure we don't miss something. Here are the general steps (assuming STP conditions for the H2S).

Step 1. Write the balanced equation. You have done that.
2HCl + FeS ==> H2S + FeCl2

Step 2. Convert what you have into mols. You have done that.
15L H2S x (1 mol H2S/34 g H2S) = 0.441 mol H2S.

Step 3. Using the coefficients in the balanced equation, convert mols of what you have (in this case H2S) to mols of what you want (in this case mols FeS).
mols FeS = 0.441 mols H2S x (1 mol FeS/1 mol H2S) = 0.441 mol x 1/1 = 0.441 mol FeS

Step 4. Now convert mols FeS to grams.
grams = mols FeS x molar mass FeS.

This procedure will work most stoichiometry problems.
Check my arithmetic. I estimated the molar mass of H2S so you need to redo that part and follow through.

To calculate how much iron (II) sulfide (FeS) is needed to prepare 15L of hydrogen sulfide (H2S), we need to use the balanced chemical equation and the stoichiometry between FeS and H2S.

The balanced equation is:
2HCl + FeS → H2S + FeCl2

From the equation, we can see that the molar ratio between FeS and H2S is 1:1. This means that for every 1 mole of FeS, we will produce 1 mole of H2S.

First, you mentioned that you converted 15L of H2S to moles. Let's assume you found that it is X moles of H2S.

Since the molar ratio between FeS and H2S is 1:1, we know that the number of moles of FeS required would also be X moles.

To convert moles of FeS to grams, we need to know the molar mass of FeS. The molar mass of iron (II) sulfide (FeS) is calculated by adding the atomic masses of iron (Fe) and sulfur (S), which are 55.85 g/mol and 32.07 g/mol, respectively.

So, the molar mass of FeS = 55.85 g/mol + 32.07 g/mol = 87.92 g/mol

To find the mass of FeS, we multiply the number of moles (X) by the molar mass of FeS:

Mass of FeS = X moles of FeS * 87.92 g/mol

By solving this equation, you will find the mass of FeS needed to prepare 15L of H2S.

Keep in mind that this calculation assumes that all reactants are completely consumed and the reaction goes to completion. In reality, there might be other factors affecting the yield, such as impurities or side reactions.