Limiting Factors and Percent Yield

Hot Dogs in the NewsTakeru Kobayashi of Japan downed 44½ hot dogs in 12 minutes.

Source: CNN.com

WHAT IF…

One hot dog = one hot dog + one bun.

Mr. Kobayashi didn’t do his math correctly. He bought 5 packs of hot dogs (10 per package) and 5 packs of hot dog buns (8 per package). How many hot dogs (according to the official formula) could he have eaten?

Hot Dogs in the News

Source: CNN.com

WHAT IF…

One hot dog = one hot dog + one bun.

Mr. Kobayashi didn’t do his math correctly. He bought 5 packs of hot dogs (10 per package) and 5 packs of hot dog buns (8 per package). How many hot dogs (according to the official formula) could he have eaten?

5 hot dog packs x 10 hot dogs

1 hot dog pack

50 hot dogs=

5 bun packs 8 buns

1 bun pack

40 buns=x

40 possible hot dogs

Practice Problems

1. 3 CuSO4 + 2 Al Al2(SO4)3 3 Cu+

20.0 g CuSO4

20.0 g Al

x

x26.98 g Al

1 mol Al

1 mol CuSO4

159.61 g CuSO4

3 mol Cu

3 mol Cu

3 mol CuSO4

2 mol Al

x

x =

=

63.55 g Cu7.96 g Cu

How many grams of copper will be produced if 20.0 g of each reactant is used? What is the limiting reactant?

x 63.55 g Cu

x

1 mol Cu

1 mol Cu70.7 g Cu

7.96 g Cu can be produced. CuSO4 is the limiting reactant.

On Perfection“Perfection never exists in reality, but only in our

dreams.”

- Dr. Rudolf Dreikurs“Perfection is our goal, excellence will be

tolerated.”- J. Yahl

Johnny took a quiz yesterday. He missed 4 questions and earned 63 points out of 70.

-Was he perfect?

-What was his possible score?

-What was his actual percent score?

Get Real!

Get Real!Mrs. Duffin ran a reaction in her lab yesterday. She predicted that 183 grams of product would be formed. The reaction only yielded 162 grams of product. But she looked really cool in her lab coat.

-Was her reaction perfect?

-What was the percent yield?

162 grams

183 gramsx 100 = 88.5 %