# chemistry

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What is the percent yield for the reaction

PCl3(g) + Cl2(g) --> PCl5(g)

if 119.3 g of PCl5 are formed when 61.3 g of Cl2 react with excess PCl3?

I don't understand how to set this up?

• chemistry -

This is a stoichiometry problem. Here is a worked example. Most stoichiometry problems are worked the same way. Copy this and remember the steps. It will save you a lot of time in the future.
http://www.jiskha.com/science/chemistry/stoichiometry.html

• chemistry -

I understand how to do the steps. but the wording is different on this problem, that is what I don't understand?

• chemistry -

The only difference here is that the problem TELLS you that 119.3 g PCl5 were formed. That is the ACTUAL yield. So use the 61.3 g Cl2 as the starting material and go through the steps in the worked example. The answer you obtain will be the THEORETICAL YIELD (Look down through the problem and that example tells you that, also, in step 4. It also explains how to calculate the percent yield).
percent yield = (actual yield/theoretical yield)*100 =
(119.3/theoretical yield)*100 = ??