Rosa
Lv 5
Rosa asked in Science & MathematicsChemistry · 8 years ago

# AP Chemistry Homework Help!?

I'm in AP Chemistry right now and we are currently on the chapter about gases.This is the homework problem that is confusing me:

How many cm^3 of carbon tetrachloride are produced when 8.0 L of chlorine are allowed to react with 0.75 L of methane at STP?

So how do you solve it? Do you need to find the limiting reactant or anything? If someone could please explain this step-by-step,that would be great!

Thanks:)

Relevance
• 8 years ago

Let's stay strictly in the gas phase for this and it makes it easy. First an equation:

CH4 + 4Cl2 --> CCl4 + 4HCl

Now since we are in the gas phase, we can work a stoichiometry problem using L instead of moles, since the two are directly proportional PV = nRT if we keep the pressure and temperature constant. So:

8.0 L Cl2 (1 L CCl4/4 L Cl2) = 2 l CCl4

0.75 L CH4 (1 L CCl4/1 L CH4) = 0.75 L CCl4

so the methane is limiting and we end up with 0.75 L of CCl4, which would be 750 cm^3