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Home , Yield (chemistry)

PERCENT

NOTES AND EXAMPLES THEORETICAL YIELD-

• Amount of product that is possible to make (from CALCULATIONS) ACTUAL YIELD-

• Amount of product that is ACTUALLY made (from doing the experiment in the lab!) PERCENT YIELD

• is a ratio between actual yield and theoretical yield to measure a ’s efficiency. It can be calculated by using the following equation:

푨풄풕풖풂풍 풀풊풆풍풅 % 풀풊풆풍풅 = × ퟏퟎퟎ 푻풉풆풐풓풆풕풊풄풂풍 풀풊풆풍풅 1. Suzi McStruggles was in the lab following a procedure, and by her calculations, she should make 27g of table salt (NaCl) so that she can season her lunch. When she finished, she actually only ended up with 15.61g of NaCl. Calculate Suzi’s percent yield of NaCl. 퐴푐푡푢푎푙 푌𝑖푒푙푑 % 푌𝑖푒푙푑 = × 100 푇ℎ푒표푟푒푡𝑖푐푎푙 푌𝑖푒푙푑 15.61𝑔 푁푎퐶푙 % 푌𝑖푒푙푑 = × 100 27𝑔 푁푎퐶푙

% 푌𝑖푒푙푑 = 57.81% 2. Henry Jenkins wants to play a prank on his crush, Suzi McStruggles, by blowing up an egg. He needs to perform the following reaction:

2H2 + 1O2  2H2O When performing the experiment, Henry started with 3 mol of oxygen gas, and it produced 4.5 mol of water vapor. Calculate the percent yield of water vapor formed. 3 mol O 2 mol H O Theoretical 2 2 = 6 mol H O 2 Yield!! 1 mol O2

퐴푐푡푢푎푙 푌𝑖푒푙푑 % 푌𝑖푒푙푑 = × 100 푇ℎ푒표푟푒푡𝑖푐푎푙 푌𝑖푒푙푑 4.5 푚표푙 퐻 푂 % 푌𝑖푒푙푑 = 2 × 100 % 푌𝑖푒푙푑 = 75% 6 푚표푙 퐻2푂 3. During the “Jug of Fire” demo, Ms. Hunt poured 9 mol of into the jug before lighting it on fire, resulting in the following reaction:

1C2H6O + 3O2  2CO2 + 3H2O After the reaction, there were 24 mol of water produced in the jug. Calculate the percent yield of water.

9 mol C2H6O 3 mol H2O Theoretical = 27 mol H2O Yield!! 1 mol C2H6O

퐴푐푡푢푎푙 푌𝑖푒푙푑 % 푌𝑖푒푙푑 = × 100 푇ℎ푒표푟푒푡𝑖푐푎푙 푌𝑖푒푙푑 24 푚표푙 퐻 푂 % 푌𝑖푒푙푑 = 2 × 100 % 푌𝑖푒푙푑 = 88.89% 27 푚표푙 퐻2푂 4. The teachers at Ryan High School were in the laboratory one night trying to create a new, top secret chemical that would combat sleepiness. This Nobel Prize winning reaction is:

3Fe + 2CoF2  1Co2F4Fe3 To showcase their product to the Nobel Prize Committee, they used

265 g of iron and produced 0.98 mol of Co2F4Fe3. Calculate the percent yield of Co2F4Fe3. 265 g Fe 1 mol Fe 1 mol CoF4Fe3 = 1.58 mol CoF4Fe3 55.85 g Fe 3 mol Fe Theoretical 퐴푐푡푢푎푙 푌𝑖푒푙푑 % 푌𝑖푒푙푑 = × 100 Yield!! 푇ℎ푒표푟푒푡𝑖푐푎푙 푌𝑖푒푙푑 0.98 푚표푙 퐶표퐹 퐹푒 % 푌𝑖푒푙푑 = 4 3 × 100 % 푌𝑖푒푙푑 = 62.03% 1.58 푚표푙 퐶표퐹4퐹푒3