Tuesday, February 8, 2011

Tue-2/8-Stoichiometry

1. We first started out the day by picking up our Goody Penny Lab sheet.


2. We then went over the basics of the start of the lab. We were given two questions to answer for the lab, which supplier made the mistake and how much more of the chemical did we need? As a class, we came up with the balanced equation of 3CuCl2 + 2Al ---> 2AlCl3 + 3Cu. We were given 3.00gCuCl2, 1.25gAl, and 1.8gCu.

3. We were then split up into lab groups. From mixing the CuCl2 and the Al in 175mL of water, we were able to figure out the following:
CuCl2- Limiting Reactant
Al- Excess Reactant
-This occurred from the CuCl2 changing colors before the Al dissolved, but to be sure, we made calculations. DON'T FORGET TO SET UP THE FOUR THINGS FOR THE GRAMS TO GRAMS PROBLEMS. We ended up with 1.418gCu when starting with 3.00gCuCl2 & 4.42gCu when we started with 1.25gAl.



4. After that we used the 1.8gCu to get 3.81gCuCl2 because that was what we needed to produce the pennies.

5. Finally we did 3.81gCuCl2-3.oogCuCl2=.81gCuCl2. This told us that we needed 3.81gCuCl2, but instead we received 3.00gCuCl2, so we were .81g short.

HOMEWORK:
-Finish Lab
-Make up Quizzes

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