The key to the redox review packet as well as the key to the extra redox balancing practice sheet have been posted in the Unit 11 Keys folder.  Study session tomorrow at 7 am in the classroom.

Don't forget your WebAssign and good luck studying tonight!

Hi, Honors Chem, I completely forgot to tell you that MONDAY IS A CHEM DAY!  Yes, you get to go to a Chem Day...finally.  There will be a sign on the classroom door to remind you, but during our regularly scheduled class period, GO TO THE LYCEUM.  Be sure to complete the handout that goes with the video and hand it in to the substitute teacher (that's my attendance, so if you don't hand one in you will be marked absent).  

Please spread the word and enjoy Chem Day on Monday!

:) Ms. F

Thursday May 15, 2014

Hello Fellow Chem-mates....

In class on this beautiful day, we practiced some more with voltaic cells and determining which substances undergo reduction and which ones go through oxidation. When trying to figure out which one participates in which equation, there is a list of Standard Reduction Potentials in the packet we have been doing. Ms. Friedmann posted videos yesterday on moodle on calculating voltages in a voltaic cell. There should be a video of what today's lesson was on I think, but essentially today's lesson was a continuation of yesterday's lesson.

One new thing we learned today was the process of Electrolysis. We did not go over it thoroughly, but we discussed the concept in class a bit. When doing some of the voltaic cell problems, some of them ended up with a negative voltage value. This means that instead of producing electricity, it consumes it. This is electrolysis.

Homework:

1. Complete the WebAssigns that are due tonight
2. Finish page 7 in the packet (1pt Extra Credit = page 8)
3. Bring in a citric fruit and read the Fruit Battery Lab for tomorrow (in the Unit 11 Labs folder)

Next Blogger will be.......

May 13, 2014

So, when we came into fifth period, Mrs. Friedmann checked in our homework.  She also said not to worry if we didn't understand the two redox equations that were homework because they were complicated.  The answers to them were...

      a. Na2Cr2O7 + 2HNO3 + 7H2O2 -> 2H3CrO8 + 2NaNO3 + 5H2O

      b. 3K2MnO4 + 4HNO3 -> 2KMnO4 + MnO2 + 4KNO3 + 2H2O


We also went over the homework on page two in the packet.  Then, we completed page 4 in the same packet.  I am pretty sure that Mrs. Friedmann will put these notes on moodle.


Finally, our homework is problems d and e on page 3 in the same packet.  Also, there is a webassign due tonight.  There are also two webassigns due tomorrow night.  One of these (called Redox equations) is for extra points that can be added on to our test.  Don't forget to add some easy points onto your grade!!

                                                               Here's a chemistry joke.

Voltaic Cells

May 12, 2014

We started class of by NOT turning in our take-home quizzes.  Instead of turning all of our work in, Mrs. Friedmann simply has us write down our answers to certain problems on a half sheet of paper so that it's easier for her to grade.

Mrs. Friedmann also explained the extra work that is now available to help boost your last test score. All you have to do is complete the WebAssign named Redox Quiz.  This assignment is due Wednesday night at 11:59.  The overall assignment is worth 10 points, and how it works is whatever you get on the WebAssign will then be added to your raw test score.  So, for example, if you got a 65/80 on your test and an 8/10 on the WebAssign, your new test score would be a 73/80.  Since this assignment can do nothing but help our grades, Mrs. Friedmann recommends that we all give it a try!

In class we started to learn about voltaic (galvanic) cells. We picked up a packet in the beginning of class and used that to take notes, so if you were absent make sure to print it out from the handouts folder! The notes aren't posted, but make sure to copy mine down if you don't have them written down.  We also used several colors to take notes with as an easy way to distinguish between reductions and oxidations.

Homework
1. Complete the top section of page 1 of the packet.  Make sure to show your work in your journal and write your final answer in the space provided on the packet.
2. Complete page 2 of the packet
3. Start on your WebAssigns! We have one due tomorrow night as well as one due Wednesday night.

The next blogger is... Elyana M.

5/9/14 Class

To start class, Mrs. Friedmann went over some homework questions from the worksheet on balancing redox reactions in acid/base solutions. Mrs. Friedmann also informed us that she has created a video going over numbers 3 and 4 that can be found on moodle. There is also a key to this entire worksheet on moodle.

We had a quiz that Mrs. Friedmann allowed us to take home to complete for homework. 

We also discussed another resource that can help us understand the unit so far called Kahn Academy Here's the link... https://www.khanacademy.org/

Homework:
Take home quiz!

4 Webassigns...

Next Blogger.....Pamela H. 

Balancing Redox Equations

Balancing Redox Equations
Scribe Post by Juliette O. (Quarter 4)
5/7/14

Agenda

First, we checked in the homework due today, the three page Electrochemistry worksheet. We then picked up three worksheets for homework, "Forming Ionic Compounds" and "Balancing Redox Equations." Then we went over the Electrochemistry worksheet. Finally, we took notes on Balancing Redox Equations in Acid-- these notes are posted on moodle. A video going over the notes will also be posted on moodle. 

Introduction

Mrs. Friedmann apologized that the tests have not been handed back yet, however she said the grades so far are quite poor. While it is the end of the school year, Mrs. Friedmann urged us to push through and continue to put in consistent effort to hold on to our grades. She reminded us that understanding homework is invaluable for the test. She also said that there will be an opportunity to make up some points tomorrow.

Homework Check

We went over the Electrochemistry worksheet in class today. 

Remember:

• Assume oxygen is not peroxide when you see O2-- assume the oxygen has an oxidation state of -2. 
• When asked to determine oxidation states of reactants and products of a reaction, start by tallying the oxidation numbers. For instance, in 2a, the substance oxidized in S in H2S, not S-2, because S is not an ion. Just because there is a -2 oxidation state does not mean there is a -2 charge--oxidation state and charge are not the same!  
• Remember, the chemical that contains the thing that is being reduced is the oxidizing agent.
• In 2d, remember that if there are 3 reactants on one side, you can identify what substance is being oxidized/reduced by identifying the oxidation numbers and seeing if there is a change in oxidation state. If there is a change in ox. state, the substance is oxidized or reduced. 
• Acronym to remember: LEORA GEROA 

Notes

See moodle for notes and a video going over the notes is also posted.

Link to Notes: http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/13_14_Unit_11_--_Redox/Unit_11_Notes/3_Class_Notes_5.7.14.pdf 

Link to Video: http://vimeo.com/94433376

Homework

• 2 worksheets: Forming Ionic Compounds and Balancing Redox Equations (#1 and 3 in notes) Link: http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/13_14_Unit_11_--_Redox/Unit_11_Handouts/5.7_Balancing_Redox_HW_1.pdf
• 4 Webassigns have been opened that are due over the course of the unit, the first due next week. Read ahead and use the text to finish the web assigns. W.A. due dates: May 13, 14, 19, 20

Class Blog 5/6/14

Half Reactions 5/6/14

Hello! today we started in class the homework, which was the chapter 4.4 worksheet and the Oxidation numbers worksheet. For homework tonight we have the three worksheets on Electrochemistry, found here. 

And here are two funny chem jokes. Please enjoy.

Today was a notes day in class. We followed Mrs. Friedmann as she took these incredible notes. 

The five main questions that need to be asked before determining Oxidation numbers are:

1) Is the substance an element

2) Is the substance ionic?

3) If ionic, are there monatomic ions?

4) Which elements have specific rules?

5) Solve for whats left!

I was very confused with Oxygen, as I am sure many others are. The Oxidation # for the Oxygen atom is almost always -2. Only when the charge for Oxygen is -1 and combined with another Oxygen atom (O2) is the Oxidation number -1. Ex: H2O2, Na2O2

Hope this helps!

Next Blogger: Juliet O.

Intro to Oxidation/Reduction Reactions - Monday May 5

To start off class, Mrs. Friedmann handed out three different worksheets. The first was a calendar for our LAST UNIT!!!! And the other two were worksheets we have to do for homework tonight.
    Mrs. Friedmann suggested reading chapter 4.4 in our book to help us fill out the reading sheet and complete the problems on the Oxidation Numbers worksheet.

Here's photos of the worksheets just in case she doesn't post them (and yes, they're due tomorrow):

But before you get started on these, read the the following notes that Mrs. Friedmann gave to us in class, as well as section 4.4 in the book:

Okay, to explain a couple things, the statue of liberty part is in my notes because Mrs. Friedmann used it as an example. See, the original statue was made of bronze, which we know is a reddish/brownish color right? Then how come the current statue is green? Well, that's because the outer layer of bronze on the statue reacted with the oxygen in the air, causing an oxidation reaction to occur in which the bronze lost electrons, causing it to actually turn into a different substance (just on the surface though). This is actually a good thing because now this new outer layer (which is no longer bronze and appears green) serves as a protective coating for the bronze interior of the statue.

And LEO and GER are just mnemonics for remembering that:
When molecule Loses Electrons it is Oxidized and
When a molecule Gains Electrons it is Reduced. (LEO the lion goes GER)

That's all! And the next blogger's Kevin Mihelic.

Acid-Base Titration Lab

     Today we did the titration lab demonstrated by Mrs. Friedman yesterday. Today's NaOH molarity was different than the demonstration and we were to do three trials and remove any results that were obviously deviant from the rest and then find the average molarity. A write-up is not necessary for this lab.

Here is the data for the lab:

Molarity of standard base used: 0.149M

Trial 1: 

HCl volume

• Initial- 10.4
• Final- 20.5
• Used- 10.1

NaOH volume

• Initial- 0.3
• Final- 14.2
• Used- 13.9

Molarity of acid- 2.05

Trial 2:

HCl volume

• Initial- 27.0
• Final- 37.0
• Used- 10.0

NaOH volume

• Initial- 27.3
• Final- 41.0
• Used- 13.7

Molarity of acid- 2.04

My third trial deviated from 1 and 2

--

The homework is to study for tomorrow's test. There will be a study session at 7 tomorrow.

The next blogger is...

Kevin M.