Thurs-2/10-Stoichiometry

**Optional: You can go to the TLC and review one of you quizzes with a tutor and you can earn the opportunity to take another quiz to earn your extra points. Also Mr. Tucker has practice tutorials in the science office, they can also be picked up in the TLC**

1)At the beginning of class we picked up two sheets, page 35, and the review for the unit. We are supposed to continue to work on page 33-35.

2)We started off class by continuing the lab test for chapter 8 we worked on yesterday. You should have noticed that the nails turned from silver to black and the CuCl2 changed to a brownish orange color. When you massed the four nails all at once you should have gotten about 1.83.

3)Then we went over quiz 5 which was on limiting and excess reactants.

4)Next, we learned a new topic called % yield. Mr. Tucker mentioned that this is one of the easiest topics of this unit and not to stress out about it to much. To figure out a percent yield there is a simple equation listed below.

<-------This is the work for question number 1 on page 35.

5)Lastly, we finished class by taking quiz 6.

Wed-2/9-Stoichiometry

1. Picked up two new worksheets (pg.33 &34) and a Chapter 8 Lab Test paper.







2. We went over the "Goody Copper Penny Factory" lab.

#1:


































# 2:


































3. We went over the Stoichiometry Quiz #5.





4 Al + 3 O 2 ----> 2 Al2O3


(you have 12.5 g of Al and 12.5 g of O2)





A)Identify the limiting reactant




















LIMITING REACTANT= ALUMINUM (23.6 grams)








B) What mass of the product can be made?


23.6 Grams of Al2O3 can be made.



4. We started the Chapter 8 lab test.

• weighed 2 grams CuCl2.
• mixed the CuCl2 with 25mL of water.
• weighed 4 iron nails: 2.57 grams (Fe)
• dropped 4 iron (Fe) nails into the solution.
• Observations (Day 1): The iron nails turned a rusty reddish color that resembles copper. The CuCl2 mixture didnt really change colors, and there was no fizzing or bubbling.

Homework:

Stoichiometry Quiz

Journal pg. 33 & 34

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

M- 2/7- Ruderman

I. On the way into class today, everyone picked up Journal Page 29. It had 4 problems dealing with Limiting Reactants (L.R.) and Excess Reactants (E.R.).

Here is a sample problem:







Step-by-Step:
1. Write what you are starting with on the left, and what you are looking for on the right.
2. Figure out what kind of problem it is (this one is grams-to-grams). Also you are trying to find out what the limiting reactant is, which means you have to do this type of problem twice.
3. In a grams-to-grams problem, the first step is looking at the periodic table and finding out the mass of the known thing. In this problem the first known thing is H2. The mass of H is 1.01g. Since there is two of them, you do 1.01+1.01=2.02, and you put 2.02gH2 on the bottom so it can cancel out the 1.0gH2. On the top, you put 1 mol of H2.
4. Next, you need to look at the periodic table, because that is the next step to finding grams (see mol island). On the balanced equation, it says that there are 2 mols of H2. You would put that on bottom to cancel out the 1 molH2. On the top you would put 2 mols H2O. You would use 2 mols H20 because that is what it says in the balanced equation. You would put it on the top because gH20 is what you are looking for.
5. Then, you would have to look at the periodic table again except for the unknown thing (H2O). H is 1.01 and O is 16.00, so you would do 1.01+1.01+16.00=18.02. You would put 1 molH2O on bottom to cance lout the 2 mols of H2O on top in the previous step. Then, you would put the 18.02 on top, because that is what we are looking for.
6. Then you would type the following into your calculator:
1.0 * 2 * 18.02 [Enter]. / 2.02 [Enter]. / 2 [Enter]. and you should get 8.921.
7. You would follow the same procedure to find out the answer to the second part of this question.
8. After doing all of the work for both problems, the answers were 8.921 and 1.126. Since 1.126 is the smaller number, the O2 would be the L.R.
II.
Then Mr. Tucker gave us back Quiz 3. The answers were:
1. Balanced Equation should be: 2H2O2----> 2H2O + O2
2. 13.2gH2O
3. 3.95L O2
III.
Then Mr. Tucker further explained....
1. What L.R. are
2. How to find the L.R.
3. How to find the E.R.
4. How to find how much E.R. will be left over
5. How much product can be made
Then Mr. Tucker went over problem 1a on J.P. 29 (just as I did above in the example).
Finally, we took Quiz 4.

HOMEWORK:
1. Journal Page 29
2. Review previous notes on L.R.
3. Quiz 5 tomorow!!!

Limiting Reactions Friday 2/4

class: today in class it was our first day of learning limiting reactions. the first step you always have to do is name the first four things to step up the equation, two on the right and two on the left. to find the reactant used you set an equation from product made to E.R used. once you figure out both of the equations that is not your answer to find out the excess reactant you have to take the lesser number of the two and once you find that answer then you wait and do SIG FIGS AT THE END. or else the numbers get messed up.

homework- look over limiting reactant sheet we did in class (picture above)

Extra Stoich Practice!!

For a problem that gives moles of Substance A and asks for mols of substance B use 1 step.  For this one step you will just use the balanced equation ratios.

For a problem that gives moles of Substance A and asks for grams of substance B use 2 steps.  Start with the balanced equation ratios for the first step and then use the molar mass (from periodic table in grams/mole) of substance B for the second.

For a problem that gives grams of Substance A and asks for mols of substance B use 2 steps.  Start with the moalr mass of substance A and then use the bal. eq. ratios.

For a problem that gives grams of Substance A and asks for grams of substance B use 3 steps.  Start with the molar mass of substance A, then use bal. eq. ratios, and then finish off with the molar mass of substance B.

For a problem that gives ml of Substance A and asks for grams of substance B use 4 steps.  Start with the DENSITY, then use moalr mass of substance A, then bal. eq. raitos, then finish off with the molar mass of substance B.  If you are ever given the grams and asked for ml, just reverse this order.

Now try to identify how many steps the following problems contain and what the steps involve (no need for any math, X and Z just hypothetical substances, just set problems up!!)

1.  How many moles of X react wirh 25.0g of Z?

2.  How many grams of Z will be produced from 12.35g of X?

3.  How many ml of Z can be produced if we also produced 35.245g of X?

4.  How many moles of Z can react with 500.0moles of X?

5.  What mass of Z would be needed to produce 10.1moles of X?

BONUS:  How many atoms of X can be produced from 25g of Z?  Use mol island for this one

Thurs - 1/27 - Stoichiometry

Today we started off by going over Drake's blog from Wednesday night. We went over some "Do's and Don't's" as we talked about a rubric for the blogs.

** MAKE SURE YOU HAVE YOUR NAME AND UNIT ON THE LABEL **

Next, we went over numbers 2 and 4 from the lab on Wednesday. Be sure to put the element symbol while doing unit conversions.

After that, we took our first Mole Quiz. You have until next Thursday to retake it; however, in order to take it, you MUST go to the TLC and review your Mole Island and get them to email Mr. Tucker saying you went over it with them.

We started a lab called Sandwich Stoiciometry. We went over it with Mr. Tucker.

HW:
- Journal page 7 (Only list if the bonds are Ionic or Covalent. We are going over the formulas Friday in class.)
- TLC (for quiz retakes)
-

T-1/25- Stoichiometry Mourikes

1) The first thing we did today was head to the math lab so that we could set up Gmail accounts. Because the computers were not working very well however, many people did not get that to work.
2) Then, using the Gmail accounts, we were able to access the blog that we will be using for the next quarter so that people can continue to stay informed if they are absent from class one day. Mr. Tucker announced that every student will need to complete a blog post ONCE during the quarter, and it will be worth 20 POINTS on our homework grade.

*IF YOU EVER FORGET THE WEBSITE, GO TO MOODLE AND CLICK ON WHERE IT SAYS PERIOD 2 BLOG, AND IT WILL TAKE YOU STRAIGHT THERE!

3) Next, we picked up pages 5 and 6, which were more practice problems with Moles. It consisted of calculating the number of moles present, along with finding the masses. A very helpful thing to use would be the MOL ISLAND CHART, which we received in class on Monday. It looks just like this...

4) We then used that chart to help solve the mole problems on pages 5 and 6, and tried getting as many problems done as possible before class was over.

SOME PRACTICE PROBLEMS INCLUDE...

HOMEWORK:

1. WORK ON PAGES 5 AND 6
2. REVIEW CLASS NOTES BECAUSE WE WILL BE DOING A LAB TOMORROW IN CLASS
3. MOLES QUIZ #1 THURSDAY!
   
   

M-1/24-Stoichiometry

1.  We picked up four sheets in class today (Mol Notes- 1page, and Pair,Dozen, Mol Lab Activity- 3pages)
 
Mr. Tucker mentioned that second semester involves a bit more problem solving and that if we do not stick with the 10-15min a night we might fall behind.....MAKE SURE TO PERFORM NIGHTLY ASSIGNMENTS!!!!

2.  We then talked about the mole concept and filled out one page of notes:
   *  A pair is 2 of something
       A dozen is 12 of something
       A mole is 6.02 x 10²³ of something (this is useful for counting particles/atoms/molecules)
  
   *A mole is then equal to this number above as well as ____g/mol as found on the periodic table
      (for instance, 1 mole of Carbon is 12.01g/1mole and 1 mole of Aluminum is 26.98g/1mole)

   *  the ratios are then 1mol/6.02 x 10²³ or 1mol/___g   (we can use these as conversion factors)

  *  We then filled out a mole island conversion chart.  This helps to know when to use the conversion factors in mole problems. 

3.  We then performed the Pair, a Dozen, A Mole Activity
      *again, a pair is 3 of something, a dozen is 12 of something, and a mole is 6.02 x 10²³ of something
      * we did a few calculations together:
                       2.5moles of donuts  x   6.02 x 10²³ donuts     =   1.505 x 10²⁴ donuts
                                                               1 mole donuts

    *  Next, we looked at a big chunk of Aluminum foil.  It was 26.98g of it.  This means that we also had 1 mole of it (because this is the molar mass found on the periodic table for Aluminum) and also that we had 6.02 x 10²³atoms of Aluminum (since 1 mole of something is always 6.02 x 10²³ of that thing)

   *Finally, we poured 18ml of water in a graduated cylinder (since water has a density of 1g/ml this means that we also had 18g of water in the graduated cylinder).   When we looked at the periodic table (H=1g/mole and O=16g/mol, and water has a formula of H2O) we figured out that 1 mole of water will have a mass of 18g/mol.  This means that in the graduated cylinder we also had 1mol of water!!!!  It really wasn't that exciting, but Mr. Tucker seemed to think so, so hence the exclamation points.  Then, since we had 1mole fo water in the graduated cylinder we must also have 6.02 x 10²³  water molecules in the cylinder as well!!!

HOMEWORK:
   *  Meet in the science lab tomorrow
  *   Transfer the mol island chart from our notes to the small notecard....we should use this when performing mole problems till we get the hang of it