Tuesday 2-22 Erick

To Begin class today we went over the lab test from Friday and went over many different ways to solve the problem. To Refresh on Friday we were given salt and asked to create a solution with a .15 molarity. One of the ways that was brought up was to use a sample volume and calculate the number of mols. Here's a different way to solve the problem.

.15M= Mol’s Liters 1.5 g NaCl 1mol

58.44 g NaCl 1.5/58.44

.15M= .o2567mol/ x

.171L

171ML

After we went over the different ways to solve the lab quiz we were given a sheet to complete on chemthink. To get to the lab go to chemthink click labs chemical reations labs and then click Precipitate lab.

After we briefly went over the lab we took notes on the rules of solubility.

Compounds always Soluble in water	Unless they have this
Ammonium NH4
Potassium K
Sodium Na
Nitrate NO3
Chlorine CL	Ag Hg Pb
Acetate C2 H3 O2	Fe Al Hg2
Sulfate	Ca Ba Pb Sr Hg2

Compounds always insoluble	Unless they have this
Oxide O2	K Na NH4 LI
Carbonate Co3	K Na LI NH4
Hydroxide OH	K Na Ba LI
Phosphate PO4	K Na NH4
Silicate SiO3	K Na
Sulfide S2	K Na NH4
Sulfite SO3	K Na NH4

The homework for the night was to Complete the lab on chemthink and to continue practicing solubility reatcions.

Fri- 2/18- Mackenzie

1. We began the day by picking up two sheets from the front. The first sheet was Molarity 2 and the second sheet was Reaction Stability 1.

Here is what they look like:

2. We went over the Molarity 1 worksheet that was assigned Thursday night for HW.

Examples:

3. We did some problems on the Molarity 2 worksheet. Mr.Tucker said that you don’t need to do #2 but it will help you for a test. He also pointed out that Molarity is the same thing as concentration so when Molarity increases so does the concentration.

Examples:

4. HOMEWORK:

Reaction Solubility 1-

*They are all double replacement reactions

*Remember: First balance the charges then balance the coefficients.

Thurs-2/17-Wittenstein

We first picked up two new sheets at the beginning of class, they were about Molarity, and Dissolving.

Next, Mr. Tucker gave us a practice quiz to see how much we knew on the solutions notes from yesterday. The quiz was about comparing solutions, colloids, suspensions and pure substances and how to find out which is which using techniques such as;

• Shining a Light
• Shaking
• Filtering
• Heating

This is what the quiz was:

Next we finished our solutions notes from the solutions notes sheet:

Mr Tucker said that 99% of the solvents we will use will be water.

We then went on to do the dissolving notes:

Remember to make sure if it is an ionic or covalent bond so you know how it reacts. Also, when you are doing the drawings, DON'T FORGET to write H2O in the beaker.

Finally, our HOMEWORK was the 2nd sheet that we picked up at the beginning of class, it was about Molarity:

To get Molarity, you divide the mols by the liters. Make sure that you turn mL into L before doing the problem. Also, at the bottom of the sheet, we have to find the L. And to do this, we divide the mols by the Molarity.

HOMEWORK: Molarity 1 sheet

Wed.-2/16-Barberis

Today in class we received 6 sheets of paper.
-4 pages of notes on solutions
-2 pages to mixture lab











Next Mr. Tucker talked about the journal quizzes from yesterday, and about the Stoichiometry exams. He also handed back the lab tests. Your group needed to turn in both the pages (data page and lab exam page) for full credit.

Then we started working on the Mixtures lab as a class. Mr. Tucker had 4 different liquid mixtures on his desk and he did 4 tests on them to determine what type of mixture they are (explained later in solutions notes).

First, as a class we examined the color and clarity of each of them.

First was milky color and clarity
Second was transluscent and dyed light blue.
Third was very muddy and murky and completely opaque.
Fourth looked identical to water.

The next thing we did to determine what type of mixture each of them was, was shake them up.

First stayed the same
Second stayed the same
Third got dark brown after shaking, but then went back to brown.
Fourth stayed the same

Third thing we did was shine a flashlight through them and see if light went through.

First- didn't go through
Second- went through
Third- Didn't go through
Fourth- Went through

We did the same with a laser pointer and the results were the same as well.

Next we went back to our lab stations with our groups and filtered each substance through filter paper.

First- Were the same before and after filter.
Second- Were the same before and after filter
Third- In the unfiltered water and also in the filter tiny chunks of dirt were still apparent, but not in the filtered beaker.
Fourth- Were the same before and after filter.

We then made a data table over all of the data we received.

After we did the lab we sat back in our seats and went over the Solutions Notes sheets.
Here is a picture of what notes we took in class.

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