Stoichiometry

Here are some more percent yield example problems. Some of these people use different methods than others. Try the problems on paper first, then view the video to see if you can get the correct answer. GOOD LUCK!!!

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Problem #1:

Magnesium metal reacts with oxygen gas to produce magnesium oxide. What is the percent yield of magnesium oxide, if 2.25 g of magensium oxide is produced from reacting 1.50 g of magnesium with excess oxygen gas?

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Problem #2:

CaCO₃ -----> CaO + CO₂
If this reaction proceeds with a 92.4% yield, how many g of CaO can a chemistry expect to produce in the laboratory, if she reacts 12.4 g of CaCO₃?

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Problem #4:

CH₄ + O₂ -----> CO₂ + H₂O

You burn 12.6 g of CH₄ in excess oxygen and form 22.9 g of H₂O. What was the percent yield of H₂O?

(Note: There are some other examples on this video that you can also try.)

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Problem #5:

NOTICE: This is a difficult problem, because it combines limiting reagent with percent yield. You will not be asked this type of problem on a test, however, if you can solve this problem, you can solve anything!

***The problem starts at about 1:32 in Part 1. The solution carries on to Part 2.

Upon heating, sodium metal reacts with chlorine gas to produce sodium chloride. If 8.30 g of sodium and 14.0 g of chlorine gas are heated together, a total of 19.5 g of sodium chloride are isolated. Determine the percent yield of sodium chloride.