Percent Yield

Today, we synthesized all of the concepts we've learned about Stoichiometry into the idea of percent yield. Percent yields are used to compare the amount obtained to the potential that could have been obtained. We learned about the real world usage of percent yields in fields such as the drug industry. It was amazing the impact such a seemingly minute improvement could have on productivity.

The way to determine percent yield is to divide the actual yield by the theoretical yield. First, you have to find what each of those are. Actual yield can only be obtained through experimentation and producing a measurable reaction. Theoretical yield is found through the same stoichiometric formulas we've used before to convert mass of a reactant to mass of a product.

Mr. Lieberman did a demonstration for the class to find the percent yield for. Sucrose was dehydrated using Sulfuric Acid to form Carbon (Graphite) and Water. After the reaction, we realized that the actual yield actually was larger than the theoretical yield. However, there were some flaws in our experiment as there could have still been excess water and acid. From this, we learned that the theoretical yield should typically be less than the actual yield.

Hope everyone had a great break, and there's only two and a half more weeks until the next one!

The next scribe is Ben T

Pumpkin Pie Reactants

I hope everyone had a great thanksgiving!

On Tuesday we turned in our Copper and Silver Nitrate Labs, and our first set of problems in the "HomeFun Problem Set." Mr. Lieberman went over 2 of the homework problems, #67 and #68, before we turned the assignment in. We further reviewed over limiting reactants during class.

Soon after the review we took the Stoich Quiz #3 - Revenge of the Stoich. If you haven't noticed yet all the titles are related to Star Wars in some way.

Over the break make sure you do the Copper Cycle pre-lab.
If you need a copy of the lab here is the link: Copper Cycle

To help you get in the limiting reactants thanksgiving mood, here are the actually ingredients to make a pumpkin pie:
1/3 c. firmly packed brown sugar
1/2 c. sugar
1 tsp ground cinnamon
1 tsp ground ginger
1/4 tsp. ground cloves
1/2 tsp. salt
1/2 tsp. ground nutmeg
2 eggs
1 1/2 c. evaporated milk
2 c. pumpkin puree

You have the following ingredients available:
3 c. firmly packed brown sugar
4 c. sugar
5 tsp ground cinnamon
5 tsp ground ginger
6 tsp. ground cloves
6 tsp. salt
6 tsp. ground nutmeg
6 eggs
3 c. evaporated milk
6 c. pumpkin puree

a. How many pumpkin pies can you make?

b. Which ingredient limits the number of cakes you can make?

c. How much pumpkin puree will be left over?

The next scribe will be Ben W.