All grades for both Chemistry 201 and Chemistry 203 are posted in Blackboard and have been submitted in PeopleSoft. I will be on campus on Wednesday afternoon if you wish to pick up your lab books. Otherwise I’ll hold on to them until June. Please stop by and collect them. Have a wonderful holiday.

Dear Students,

It is Friday late afternoon and I am still grading lab reports and lab notebooks. It takes time and I ask for your patience. I will keep you posted and let you know when the grades are posted to Blackboard. This will not happen before Monday.

Since both classes have exams this week I’ll be available for questions and problem solving practice as follows:

9:00 – 11:00 Monday – focus on Chem 201

11:00 – 12:30 Monday – focus on Chem 203

5:00 – 6:00 Monday – focus on Chem 203

Vic found a story that is very timely to our current discussion. Please read it on the Chicago Tribune website:

http://www.chicagotribune.com/news/nationworld/la-fg-fukushima-radiation-20111120,0,4008193.story

or you can access a pdf file I created…

The exam will cover material beginning with:

Chapter 21

21.4
Calculate K, ΔG and E^ocell from each other.

Calculate the potential of a concentration cell.

21.5 (no test questions on this section)

21.6 (no test questions on this section)

21.7

Predicting the products of electrolysis
Diagram an electrolysis cell
Apply the relationship between current, time and amount of substance

Chapter 22 will not be on the test.

Chapter 23

All sections are covered in this chapter.

Chapter 24

As mentioned in class – problems referencing p. 1076 will not be included.

24.3 (no test questions on this section)

24.6 (no test questions on this section)

Very little from 24.7 will be included but you need to know the basic difference between fusion and fission.

Sections not excluded above are included on this exam.

*********************************************************************

I’ve posted some new handouts to help you with the transition metal/coordination compounds topic. I’ve posted a reference guide for Inorganic Nomenclature. Also I would like you to read this article: A millennial overview of transition metal chemistry and answer the questions of this worksheet (answers are given at the end of the worksheet but please try to answer the questions on your own first!)

To prepare for the quiz on Thursday please make sure you can do the following:

1. Write electronic configurations for the first row of the transition metals

2. Give the MOST COMMON oxidation states for the first row of the transition metals.

3. Determine the oxidation state of a metal in a coordination compound.

4. Identify if a ligand is monodentate, bidentate or polydentate.

5. Apply the rules for nomenclature of coordination compounds to convert from formulas to names and names to formulas. (Do all the homework problems available on this topic – practice!)

6. Answer questions about periodic trends for transition metals. (section 23.1)

7. Determine if a tranistion metal is paramagnetic or diamagnetic.

8. Visually identify inorganic compounds on this page by color.

9. Answer questions about metallic behavior and reducing strength.

10. Discuss the toxicity of mercury.

The quiz covers the material in Chapter 23 from the beginning until the end of sample problem 23.3. It does not cover section 23.2. There is a lot of information in these few pages – so read them carefully and take notes!!

I’ve posted a quiz. It covers the entire chapter so some questions would best be considered after the exam – ones related to Gibb’s Free Energy, Equilibrium, etc. Anyway, here is the link:

Electrochemistry Practice Quiz

I haven’t posted the answers yet. Email me if you have questions you are not sure how to answer.

I’ve created a new handout summarizing the rules for assigning oxidation numbers to the atoms in chemical compounds. Chemistry 203 students should use this for review. It will be very important to have the rules memorized before beginning electrochemistry.

I’ve created a new video from problem number nine on the last quiz. In this video I work out a problem involving Ksp. Here are the relevant links:

Video Library

Part One Ksp

Part Two Ksp

A problem solving session for thermodynamics problems will take place in my office from 9:00 a.m. to 11:00 a.m. on Wednesday, October 19th for Chem 203 students. All are invited.

If you are still trying to wrap your thoughts around the first and second laws of thermodynamics – try watching this puppet show.

The latest issue of Journal of Chemical Education contains a fun puzzle that will help you learn the names of the chemical elements and the names of the bones.

Download Activity

This activity is from: http://pubs.acs.org/doi/abs/10.1021/ed200231g

It happens to everyone, myself included. The brain crash. The quiz was difficult because it included problems that used the quadratic formula and the first problem was a combined Ksp, Kf problem. It takes nerves of steel to do these problems.

As I promised I’ve adjusted the syllabus and we will take another quiz on this topic on Tuesday – and it will go MUCH better. Why? One reason is that I’ve created a video in two parts that will show you exactly how to solve the first problem on the quiz. You can stop and start the video. You can email me any questions you have about the solution. (Why couldn’t I solve this problem in class on Thursday – a simple sign error – I added when I should have subtracted. It is always the little things!).

So download the new syllabus, watch the video, and come to class on Tuesday ready to solve these problems!

Syllabus

Video Part One

Video Part Two

Video Library

I created these videos with Camtasia. I believe the technology used is “Flash” so they may not work on platforms that do not support “Flash”. Hopefully with computers everywhere you will find a way to watch them.

This local event is well worth attending:

http://www.iit.edu/csl/phy/lederman_lecture

Students must combine many skill sets for the laboratory on the Ksp of silver chromate. They must carry out very careful volume measurements to prepare solutions of known concentrations. They use the computer with the Ocean Optics spectrophotometer to gather data on the absorbance of these solutions. They work with a variety of glassware and must choose the right equipment for the best results.

Team work is required in these laboratories.

Careful use of the Pipet

This morning when I woke up I couldn’t wait to go out and look at the remains of last night’s fire. Some amazing chemistry takes place when wood burns.

All the big wooden logs are gone. What is left is black and gray. A tremendous amount of energy has been produced, enough to keep ten people warm all evening on a cool (40s fahrenheit) night. There is no sign of incandescence now. But there is still beauty. Let’s look closer.

Beneath the grating we can see lumps and powder. The lumps are black the powder is gray but on closer inspection the powder appears to be white and black particles mixed together.

I gathered up the coals and ashes and put them into a plastic bag and brought them into the house. Next I used a colander to separate the lumps from the powder.

This wood ash contains ten times more potassium than sodium. It can be used to make potassium hydroxide – a kind of lye. My next step is to dissolve all of this ash into boiling water, pour it through a filter (hot filtration), and evaporate most of the water. (I’ll do this in the laboratory and share the results on a future post.) This will produce a solution of mostly potassium carbonate. The carbonate can be precipitated with calcium hydroxide (slacked lime). This will form calcium carbonate solid that can be filtered out leaving a supernantant of potassium hydroxide.  This “lye” can be used to make soap. http://www.grannyslyesoap.com/index.html

Charcoal

Here is the charcoal. The word char-coal tells us that this is coal formed from the charring (burning) of something. Charcoal formed this way is very soft. And it still has a lot of potential energy. The gases have been removed but charcoal will burn. It burns hotter than wood and with very little smoke. This is what we typically buy for our charcoal grills. Charcoal can also be used to draw on paper – paper is made of cellulose from wood. But that’s another story…

charcoal drawing

Tonight I sat out in my backyard with my family and friends and we watched a fire burn. It amazes me how easy it is to become mesmerized by fire – it changes constantly as the logs burn down to ashes. But what is fire?

According to Wikepedia:

Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products.^[1] The flame is the visible portion of the fire and consists of glowing hot gases. If hot enough, the gases may become ionized to produce plasma.^[2] Depending on the substances alight, and any impurities outside, the color of the flame and the fire’s intensity will be different.

Glowing hot gases are very beautiful. So are the incandescent embers.

campfire in the city

The oxidation that is taking place is the reaction of cellulose and oxygen. Cellulose is a polymer of glucose, a sugar molecule. As the wood burns the gases released include carbon dioxide, carbon monoxide, water vapor, and gaseous hydrocarbons.

From “How Stuff Works” : http://science.howstuffworks.com/environmental/earth/geophysics/fire1.htm

• Something heats the wood to a very high temperature. The heat can come from lots of different things — a match, focused light, friction, lightning, something else that is already burning…  
• When the wood reaches about 300 degrees Fahrenheit (150 degrees Celsius), the heat decomposes some of the cellulose material that makes up the wood.  
• Some of the decomposed material is released as volatile gases. We know these gases as smoke. Smoke is compounds of hydrogen, carbon and oxygen. The rest of the material forms char, which is nearly pure carbon, and ash, which is all of the unburnable minerals in the wood (calcium, potassium, and so on). The char is what you buy when you buy charcoal. Charcoal is wood that has been heated to remove nearly all of the volatile gases and leave behind the carbon. That is why a charcoal fire burns with no smoke. 

heat and light: two forms of energy

What I noticed the most was how lovely it was to sit around a fire and listen to conversation, watch the family roast marshmellows, and think how very lucky I am to be able to experience this wonderful phenomena.