A Farewell and Le Chatelier's Principle

Mr. Jeff Yordy

As Dr. Wegley announced, Mr. Jeff Yordy of the science department passed away over the weekend. He taught biology and led horticulture to many achievements in his past 30 years at GBS. Mrs. Friedmann was very close with him. We all wish the best for his family, friends, and students! 

Le Chatelier's Principle

With regards to the chemistry class, it was a matter of note taking and concept grasping with Le Chatelier's Principle. These notes and 4 handouts will soon be up on the Moodle page somewhere in this resource page. We then moved on to complete the first two worksheets which will also be found in this page.*

*If the notes are not posted by the time you see this, here is a sloppy copy of mine:

 

Here is the key to the graphs and problems on the first two handout pages we got to in class:

Homework:

*Finish the 4 handouts given on Le Chatelier's Principle

*Complete the webassign due Tuesday night at 11:59 P.M.

The next blogger will be…(drumroll)…Brandon M.

Ice Day!

To start off class today, Mrs. Friedmann checked in our homework and we went over the homework.( keys are posted). In addition Mrs. Friedmann gave us an OPTIONAL worksheet that will help you with the ice problems. The sheet only functions as extra practice and will not be checked in, but it is recommended you do them to prepare for the test.

Ice, Ice, Baby!
- For the rest of the class Mrs. Friedmann introduced to us the last topic of this section which is: how to solve ice problems. I will not go in depth with the explanations since there is a video posted that goes over a good explanation on how to do the ice problems and there are notes as well. All can be found on the moodle page.

- In addition Mrs. Friedmann has posted the answer key to the review packet and a video that goes with it. It is recommended that you use these tools to study for the test tomorrow.

HOMEWORK:
- STUDY for test tomorrow!!--- good luck

This is what will happen to our brains after the test tomorrow!!!

NEXT BLOGGER: Grace K.

Equilibrium Constant Calcs and "Q" Calculations

March 19, 2014

Scribe: Serene P. 

To begin class, Ms. Friedmann checked in our homework. She stated that we each earned two more points on our previous chemistry test due to someone finding an error in the test’s answers.

We were not assigned any more webassigns. However, our unit test will be this Friday. We were given the unit review packet, and the answers will be posted soon along with a video. You will not be able to do questions 26 or 27 tonight, but you can attempt doing so by previewing tomorrow’s notes that are in moodle.

http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/1314_Unit_9_--_Equilibrium/Unit_9_Handouts/3.19_Kinetics_Equilibrium_Review_Packet.pdf

We also picked up a worksheet titled “Q” Calculations which was homework.

We first corrected the “equilibrium expressions” worksheet. Instead of taking down the notes, Ms. Friedmann went through her pre-written note sheets that are posted on moodle.

We also looked through two of the worksheets that we had picked up yesterday titled “equilibrium constant calcs” and went through a few of the problems together. However, problems 3,4,6, and 8 are assigned as homework tonight.

http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/1314_Unit_9_--_Equilibrium/Unit_9_Handouts/3.18_Keq_and_Q_Calcs_Ws.pdf

Here are the notes from today:

http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/1314_Unit_9_--_Equilibrium/Unit_9_Notes/3_Notes_on_Equilibrium_Constant.pdf

and..

http://gbs-moodle.glenbrook225.org/moodle/file.php/12015/1314_Unit_9_--_Equilibrium/Unit_9_Notes/4_Notes_on_Q.pdf

Tonight’s homework:

Optional Review Packet, video and key to be posted soon

Unit Test Friday

Q calculations worksheet

Finish problems 3,4,6,and 8 of equilibrium constant calcs worksheet

The next blogger will be Ambreen A.

Continuing Equilibrium

Tuesday the 18th

By Hayden Northwick

We begun class by showing Mrs. Friedmann our graph, which was homework from the night before.  Then she handed back some graded work of ours including the latest typed up lab we did and also the packet we did at the beginning of the equilibrium unit when she wasn't there.  We spent the majority of the class time going over the packet. The key can be found in moodle or at this link.  

The only homework we have tonight is to do the 1st of the 3 worksheets we collected in class today for tomorrow.  

In the last 30 seconds of class, Mrs. Friedmann did a quick demo where she poured a liquid on the counter in a shamrock shape and lit it on fire.  It burned with a green tint. Happy belated St. Paddy's day.

The next blogger will be: Serene P.

Equilibrium Simulation

Equilibrium Simulation (Lab)

     Today we turned in the packet on rates of reactions that was due. We then went on to do a lab in class called Equilibrium Simulation. In this lab we used beads to represent atoms and molecules in order to simulate equilibrium. There were groups of three, in which one person represented the forward reaction by joining two beads together, the second person represented the backwards reaction by splitting them apart, and the third person timed the reactions. The data was then collected into a table which you can find in the Unit 9 Labs and Activities Section, or you can simply look below:

For homework we were supposed to graph the data and label it. That is all that is due tomorrow. The next blogger is: Hayden

Reaction Rates Investigation

Reaction Rates Investigation Lab

     On Friday we conducted the Reaction Rates Investigation, where we tried to determine how certain variable changes affected the rate of reaction of Alka-Seltzer and water. Here is the information you will need to fill out the sheet that is due MONDAY.

Effect of Temperature on Reaction Rate

Procedure:

• Take out a tablet of Alka-Seltzer and weigh it on a scale. Record the weight.
• Fill up 1/2 of the cup with either Hot/Room Temp./Cold water (pick one per trial)
• Measure the temperature of the water in the cup
• Put a tablet of Alka-Seltzer into the cup, place the cover on, and flip over the cup.
• Time from the point the Alka-Seltzer comes into contact with the water to the point when it pops.
• Record the time in you're data table.
• Do this 2 more times with the 2 remaining temperatures of water

Data Table:

TRIAL 1 (Room Temp.Water)

Weight of Alka-Seltzer: 2.20 grams

Temperature of Water: 21.1 Degrees Celsius

Reaction Time: 10.22 seconds

TRIAL 2 (Hot Water)

Weight of Alka-Seltzer: 1.95 grams

Temperature of Water: 55.0 Degrees Celsius

Reaction Time: 2.8 seconds

TRIAL 3 (Cold Water)

Weight of Alka-Seltzer: 2.05 grams

Temperature of Water: 3.8 Degrees Celsius

Reaction Time: 40.57 seconds

Conclusion: Base your conclusion on you're observations of the effect temperature has on reaction 

Effect of Surface Area on Reaction Rate

Procedure: 

• Take out an Alka-Seltzer Tablet, and split it into 3 chunks, 1 chunk, or ground in a Mortar and Pestle
• Weigh the Alka-Seltzer, record.
• Fill up 1/2 of you're cup with Room Temp. water.
• Measure temperature of the water, record.
• Put the Alka-Seltzer into the cup, cover, and flip.
• Record the time it takes from contact to the pop of the cup.
• Do this two more times with the other surface area options.

Data Table:

TRIAL 1 (Ground)

-Weight of Alka-Seltzer: .93 grams

-Temperature of Water: 20.9 Degrees Celsius

-Reaction Time: 11.36 seconds

TRIAL 2 (3 chunks)

-Weight of Alka-Seltzer: 1.01 grams

-Temperature of Water: 21.1 Degrees Celsius

-Reaction Time: 14.21 seconds

TRIAL 3 (1 Chunk)

-Weight of Alka-Seltzer: 0.99 grams

-Temperature of Water: 20.9 Degrees Celsius

-Reaction Time: 18.45 seconds

Conclusion: Base your conclusion on you're observation of the relationship the different surface areas have on the reaction time.

Effect of Concentration of Reactants on Reaction Rate

Procedure:

• Take out a tablet of Alka-Seltzer, weigh it and record.
• Fill up either 1/4, 1/2, or a full cup with Room Temp. water
• Record the temperature of the water
• Place the tablet into the water, cover, and flip
• Record the time it takes for the cup to pop
• Do this two more times for the 2 other concentrations of water.

Data Table:

TRIAL 1 (1/4 Cup)

-Weight of Alka-Seltzer: 1.69 grams

-Temperature of Water: 20.6 Degrees Celsius

-Reaction Time: 11.6 seconds

TRIAL 2 (1/2 Cup)

-Weight of Alka-Seltzer: 1.66 grams

-Temperature of Water: 20.9 Degrees Celsius

-Reaction Time: 13.25 seconds

TRIAL 3 (Full Cup)

-Weight of Alka-Seltzer: 1.72 grams

-Temperature of Water: 20.9 Degrees Celsius

-Reaction Time: 8.3 seconds

Conclusion: Base your conclusion on you're observation of the effect changing the concentration has on reaction time. Our trial 3 may have been invalid considering the reaction time should have been longer than trial 1 and 2.

Homework

The packet that we filled about halfway on Thursday and this lab sheet are both due Monday. I didn't take a video of the pop, sorry ;(

Rate Expressions and Rate Constants

Rate Expressions and Rate Constants

          To start off, Mrs. Friedmann told us she was aware of the fact that there was a field trip tomorrow and that some people wouldn't be here. Tomorrow we will be doing a lab and those not here can use the data posted by Friday's blogger. We will not be doing a write-up for this Lab

       Rate Expressions and Rate Constants packet

          We worked together on the packet we got a couple days ago. The key to what we got through today can be found on moodle here. As the packet shows, there is an easy and hard way to do Example 1A. Mrs. Friedmann only showed us the hard way so we would know how to use it. We will always be able to use the easy way for the questions we will be given.

Homework

• Complete the Rate Expressions and Rate Constants packet by Monday
• Complete the lab worksheet by Monday
• There may be Webassigns for the weekend, but if there are they won't be due until Monday night

I'm hesitant to assign a next blogger because I don't know who is and isn't going on the field trip. We'll figure it out tomorrow.

Webassign error/ score readjust

For the third webassign on the last part of the chapter, the correct answer is the one with A and C.. Although webassign marks this answer as wrong, it is the correct one and Mrs. Friedmann will adjust the scores.  Don't worry :) and good luck!

Notes on Notes

Happy Tuesday Everyone!

Today, we took the allll the notes we neglected to take on Friday or Monday. The topics were collision theory, reaction mechanisms, reaction rate and factors affecting reaction rate. I give a short summary of each of them below, but you can find the real notes at http://GBS-Moodle.glenbrook225.org/moodle/mod/resource/view.php?id=86333

Collision Theory

When a reaction takes place, it is because molecules collide with each other at 1) the right speed and 2) the right orientation. The "activated complex" is this transition stage between reactants and products during a reaction. The "right speed" is otherwise none as the activation energy.

Reaction Mechanisms

A reaction does not happen all in one go; a series of steps makes a reaction happen. The "crash" happens, and then the old bonds break to form new bonds. The overall reaction, called the complex reaction, given on paper is just the end result, and many elementary or intermediate steps are taken to get there. 

Reaction Rate

This is a measure of how quickly the reactants in a reaction become products, or how much reactant is used over time. We will calculate this in units of molarity (mol/liter) per any unit of time (seconds, minutes, etc). The elementary steps of the reaction all have different required activation energies, and the step with the highest activation energy will take the longest to complete. This is called the rate-determining step, because it will be the factor that affects the speed of the reaction.

Factors Affecting Reaction Rate

Factors include: an increase in temperature, an increase in concentration (molarity), an increase in surface area, and the addition of a catalyst. A catalyst lowers the activation energy of certain slow elementary steps and can also provide different paths for a reaction to take, making it go faster.

Homework:

Check the answers to the equilibrium packet assigned yesterday (http://GBS-Moodle.glenbrook225.org/moodle/mod/resource/view.php?id=86334)

2 WebAssigns are due on Wednesday by 11:59 pm 

Equilibrium

Equilibrium and Sub Day!

Although Ms. Friedmann was not here today to show off her amazing teaching skills, we had a "sub" in class to "substitute" for her. For the whole class period, we worked on an interesting equilibrium packet.

Homework:

• Finish the Equilibrium packet for tomorrow
• Start working on the 3 WebAssigns that are all due Wednesday

Kinetics and Equilibrium

Introduction to Kinetics and Equilibrium Unit

Friday, March 7, 2014

Today's chemistry class was all about the "It's Friday" spirit. It all started with Ms. Friedmann and Kevin G. balancing on the edge of the counter with one foot. This demonstrated holding an equilibrium…

Instead of taking notes, Mrs. Friedmann thought it would be a good idea to demonstrate some bigs ideas of this unit by doing activities in the old pit. These activities involved the class following directions:

• We tried the have a balance between two groups of people; this was done by having the same number of people on a side, making it symmetrical. 
• We tried having a group of 11 and 8 and had a flow of people traveling from one side to other other. The same number of people walking from one side maintained the balance of 11 and 8 and was not symmetrical.
• We tried having the two balanced groups of people, but everyone was moving in constant motion on each side. After walking in circles for a few moments, we had still maintained a balance.
• We tried having two groups where one group had two people walk over simultaneously with one person from the other group. This switch-up eventually led to one person on one side and the rest of the class on the other. This ended up not maintaining the balance because a different number of people from each side walked during each pass.

Lessons Learned:

• What comes in, must go out
• Equilibrium does not mean symmetrical
• Chemical reactions may appear as if doing nothing but is maintaining equilibrium
• Dynamic Equilibrium always moves, but is also always balanced

Next we went back into the class, so Mrs. Friedmann could bring fire. I left class 5 minutes early, so if anyone wants to recap what happened there in the comments, that'd be great.

Homework:

1. 2 crash course videos that you need to watch and take BIG-IDEA-ONLY notes where this should only take up 2/3 or 1 journal page for both videos 

• https://www.youtube.com/watch?v=7qOFtL3VEBc&feature=youtu.be
• https://www.youtube.com/watch?v=g5wNg_dKsYY&feature=youtu.be

1. Unlike the calendar, Mrs. Friedmann will NOT be having us do a web assign over this weekend, but will be assigned at a later date.

The next blogger is…Cool Chris

Entropy, Spontaneous Reactions, and Gibbs Free Energy

Entropy, Spontaneous Reactions, and Gibbs Free Energy
Scribe Post by Juliette O.
3/4/14

Agenda

First, we turned in the Hess's Law Lab Write Up, and for those who did not finish on Friday the Thermochemistry quiz. We then picked up the three pages of notes on Entropy, Spontaneous Reactions, and Gibbs Free Energy, and the worksheet (2 sheets) for homework. These are posted on moodle. We were reminded that the test is on Thursday-- remember to print the review packet and study it. The video is posted, and there will be a study session at 7 in the morning on Thursday. Next, Mrs. Friedmann showed us a quick demonstration on entropy and we then went over the notes. Finally, we went over the first two problems on the homework.

Notes

Homework Questions 1 and 2

Introduction to Notes

• Enthalpy is the energy in the bonds of chemicals, but enthalpy and entropy changes allow us to predict if the reactions reacts spontaneously.
• Entropy: measure of disorder in the universe, as in all the systems and surroundings 
• Processes increase disorder. 

Demonstration and Notes

Mrs. Friedmann took out a deck of UNO cards and spread them out haphazardly on the table. She pointed out that without work, someone physically organizing them, if thrown out on the table the cards are unlikely to end up in a neat stack. Work is required for that to happen. The universe is more likely to fall into disorder than order because of this. 

Order <---Requires Work-------Naturally Occurring--> Disorder

• Spontaneity=disorder, and you need work to get order.
• Example: my room had increased entropy at the end of the week! 

Mrs. Friedmann then split the deck of cards in half and put an organized half on the left side of the room and the disordered on the right side of the room. If the messy, disordered deck is on the right and the ordered deck on the left, the disordered in the products have a higher entropy. Therefore, if entropy is higher on products and lower on the reactants side, + number for delta S. 

REACTANTS --------> PRODUCTS         Spontaneous and Positive (the universe is naturally 

less entropy                       more entropy      like this b/c it is more likely to land in disorder)

more entropy                    less entropy         Negative number for delta S

• Example of a spontaneous reaction: fire burning-- it will continue burning and will light in the right conditions.
• However, many spontaneous reactions happen slowly, for example, the reactions in the body are spontaneous but occur slowly. Enzymes speed up these reactions by decreasing the activation energy in our body. Even when enzymes are involved as catalysts, the reaction is still spontaneous! 

Crash Course on Entropy:

Homework

• 3 Webassigns, two due tonight, one due tomorrow
• Worksheet (2 sheets; questions 1 and 2 done in class, 3 and 4 to be finished individually)
• Work on review packet! The video is posted on moodle.
• Study for test Thursday! Study session is at 7 AM Thursday morning.