27 April 2020, 1:00 pm

I have updated everything and you now have the latest numbers that will be used to determine your grade unless you get back to me with other information soon.

The final exam is now available and you can take it any time between now and Wednesday morning. Remember there is an opt-out option for the final exam as explained below. On Wednesday morning I will grade the final exams and then calculate final grades. That means that you should have anything you want me to look at for your grade to me before Wednesday at noon.

There are a couple of students who haven't turned in the final lab report and it is contributing to a failing grade. Get all labs in to me as soon as possible. Wednesday noon is the same deadline for the lab reports.

27 April 2020, 5:30 am

Later this morning I will grade everything that I have received and put zeros into the ones that are to be graded and that I haven't received. If you have a zero it means that I don't have that assignment or it has been misplaced. Let me know about the situation so we can get everything settled. A couple of lab assignments that we didn't get to do have dashes. Dashes don't contribute to the total grade and you can just ignore them. It is also true of the entries in the lecture part of the class that have dashes.

The final exam will cover all of the material for the whole semester. You have some options as explained in the previous post. In case you are planning to take the final exam I give a note about the last content area below.

A Note of Caution - Don't Blindly trust the internet!

When grading the last open book exam over this material I observed that several students used the following equation that they had found on the internet for all of these problems:

pH = (14 + pK_a + log C)/2 = ½(14 + pK_a + log C)

To derive this equation you have to make some assumptions. One is that there is some salt of the weak acid available, but the biggest one is that for the weak acid HA, the [OH^-] = [HA]. These concentrations are the initial concentrations after mixing, but before reacting. This is only true at the equivalence point and is equivalent to saying that you have the same moles of the weak acid as you have moles of the strong base in the initial solution. In other words this only works for buffer systems at the equivalence point.

So, if you are trying to use it before or after the equivalence point it won't give the correct result. It will often be close because buffer systems tend to keep the pH stable, but it will not give the actual value that is wanted. Here is a derivation of the formula.

This is a good example of how looking things up on the internet can get you in trouble. The table method that I have shown you always works for any of the situations. Bye the way, the C in this formula is the concentration of the salt of the weak acid. When using the equation you should use the concentration of A^- from the complete reaction line of our method of doing the problems. So, another assumption is that a very small amount of the A^- reacts with water to make HA.

21 April 2020

The fourth exam is now available and can be taken in any 3-hour block until Friday morning.

This is not the final exam. Everyone must take this fourth exam. The final exam will be done next week and it is the one you can opt out of. You can not opt out of this exam.

16 April 2020

Here is the rest of our schedule for class meetings at 8:30 am.

Tomorrow, on 17 April we will go over questions about Part II of the lab and answer any lingering equilibrium questions.

On 20 April we will go over questions about Part III and IV of the lab and answer any lingering equilibrium questions.

In general, I will be available during all of these class times to clear up any last-minute questions about the lab or about the last exam.

The fourth exam, over equilibrium, will be due on 24 April and the final exam, over the whole semester, will be due on 29 April as explained in the last post below labeled 14 April 2020.

Stay safe!

14 April 2020

We are now past the due date for all of the equilibrium homework. If you have completed all of them I have put the average of that homework into three quiz scores to give you credit for that work. I have put zero for those that I haven't received. If you have a zero you should get it done as soon as possible. I have now also set it so that it drops the lowest quiz.

With this completed we can think about the 4th exam and the final exam.

The fourth exam will be due as scheduled at 10:30 am on Friday, 24 April 2020. Because we are through the material and some of you might want to take the exam early due to the difficulties of the day, I have decided to make it a timed 3-hour exam, but to make it available anytime from 8 am on Tuesday, 21 April 2020 until it is due. You could, for instance, take it during your regularly scheduled lab time or during our usual 7:30-10:30 on Friday morning, but whenever you take it be sure to have a 3-hour block of time to devote to it. It is an open-book exam with eight questions.

I have prepared a 10-question final exam over the whole semester. It will also be given as an open-book, timed 3-hour exam. If you take this exam it will be due at 10:30 am on Wednesday, 29 April 2020, as scheduled by the registrar. I will make it available at 8 am on Monday, 27 April 2020 so you can take it during any 3-hour block between then and when it is due.

Because of the unusual circumstances this semester and because it is my experience that the final exam doesn't change the grade very much, I have decided to give another option where you don't have to take the final exam that I have prepared. I'm also hoping this might relieve some of the pressure and stress at this difficult time. If you decide to not take the final exam I will use the larger number between your exam average and your total score in Canvas and put that number into Canvas as your final exam score.

In addition I will provide an option for you to opt out of the final after you have started it and evaluated how you might do. Here is what I am posting with the final exam about this.

If you decide to opt out of this final exam, you must email me before the time that the exam is due with a subject of "CHE105 Final Exam" and a statement that you do not want me to grade the exam. The email must be postmarked before 10:30 am on Wednesday, 29 April 2020. Without that email I will grade the exam and that result will be used as your final exam score in Canvas.

I emphasize that there are only two choices: either take the final exam and accept your grade as the final exam score or don't take the final exam and use the exam average of the first four exams, or the calculated total in Canvas, as your final exam score. If I grade the final exam I will use that score whether it helps or hurts compared to the other option. Also, if you only look at the exam, still send the email. If you don't do any problems or only do a couple of problems and then quit without sending an email, you will be averaging some zeros and your score for the final will not be good. If you don't open the final exam, you don't have to send an email.

Finally, I will be available tomorrow (Wednesday) during our regular class time to go over equilibrium problems and to introduce you to the last lab assignment.

8 April 2020

Before anything else I want to wish you as nice of an Easter as is possible for you and hope that you can find some peace in the middle of these very stressful times.

I haven't changed anything with the schedule, but I want to give you some information that may be helpful.

I have added a couple of links to the top of the equilibrium site and I have added another video in the media box that is on each page.

At the top of the equilibrium webpage (http://studentworldteacher.net/courses/genChem/equilibrium/) there is now a "Menu LInks" option that will give the links from the menu with the names that I call them and the dates that we discussed them in our online class. This may be helpful if you are having problems with the pop-up menu or if you want a quick look at the schedule. There is also a new "Concept Review" link at the top of the main page that lists all of the equilibrium concepts that we have covered and that you should understand for the next exam. Hopefully it will help when you are studying for Exam 4.

In the media box for the last few pages I have put a "Class Video". This is a condensed version of the example problems we did in class that day. You can still get the whole video of the class by going to conferences. The "Video Links" option will bring up the videos in a new window.

After our online class next Monday, 13 April 2020, we will have gone over all of the webpages that I have prepared. After that date I will be available during our regular class time (8:30 am, MWF) to answer questions and prepare for the next exam.

Next Wednesday, 15 April 2020, I will also go over the last Lab assignment that I gave you previously (see http://studentworldteacher.net/courses/genChem/equilibrium/equilibriumLab.htm). This assignment will take some extra thought and some dedicated time to complete. Remember it is taking the place of several 3-hour lab sessions. After Easter we only have two more weeks, so starting it now would be a good idea. You don't have to do it all at once and can send me what you have just for the first or second part to get feedback if you want to. I can also set up individual conference sessions anytime or do them during our regularly scheduled lab time if that would help. Send me an email to set it up. I have prepared a document to help you get started. You should think about the questions in that document before this discussion about the final lab assignment.

Enjoy the sunshine and anything else that you can.

Take care!

Dr. Burgess.

30 March 2020

Now that we know we will be online for the rest of the semester, I have made some decisions.

Lecture

The equilibrium section, through the nine webpages that I have written, will be the final content area of the semester.
We will continue with the conference sessions on Monday, Wednesday, and Friday during our scheduled class time as we have been doing. Looking at the homework, there should probably be a few more students at those sessions.
The homework from those webpages will be due as now scheduled, basically the day after we cover them in class. Those assignments will count toward quiz grades.
We will have an online "take-home" exam over the equilibrium material as scheduled (Friday 24 April), but I may allow it to be taken earlier to accommodate changed schedules due to the shutdown. It will again be timed at 3 hours.
I still need to make a decision about the final exam, but it won't be my usual ACS standardized exam in any case.

Lab

All of the labs assigned to date will contribute to your lab grade. If you have any missing labs you should get them in as soon as possible.
We will do one more lab, dealing with equilibrium, that is broken down into four parts.
- Read and analyze the lab information. 5 points.
- Create a standard curve. 5 points.
- Construct an equilibrium table. 5 points.
- Calculate K. 10 points.
In an effort to give everyone maximum flexibility, this last lab can be done any time between now and 21 April 2020, but I suggest you do it as soon as you can to avoid problems later. We have an exam the week of the 21st, so getting it done earlier will leave more time to study for the exam.
The last lab can be obtained from our regular class webpage or from here: http://studentworldteacher.net/courses/genChem/equilibrium/equilibriumLab.htm

26 March 2020 - More Lab Clarification

Good afternoon on this sunny day! I hope you are all doing well.

I got an email wondering about the labs. I have been busy doing the lecture webpages and haven't developed any lab materials beyond what you already have available. The last lab to be handed in was the kinetics/color lab using the data from the class webpage link called Kinetics Lab Experiment. There are no other lab assignments to hand in at this time.

I will assess where we are as we learn more about how long we will be off campus. If we do have some online lab assignments I will give you at least a week to get them done. So, nothing for the next week either. One less thing to stress over for right now. Use the time to study the lecture pages, do the homework on those pages, and go over the "old" homework that we used to take quizzes from.

Let me know if you have other questions.

There still seems to be some confusion about the kinetics/color lab. I have copied the post for 17 March that explained the assignment.

17 March 2020 - New Lab For This Week

I took some data yesterday in order for you to complete this week's lab. It is a kinetics lab and should be good preparation for the exam on Friday. You don't need to write a complete lab report, just explain your work and show the result. Consider the numbers I gave to to be averages and you don't need to calculate a +/- for this report. You can access it from the right side of our class homepage or use http://studentworldteacher.net/courses/genChem/kineticsColor.htm.

25 March 2020 - Schedule Clarification

To make sure we are all on the same page in terms of the webpage content and webpage homework that is taking the place of our class meetings and quizzes, I have listed the class dates and the page (as listed in the menu) that will be discussed during our conference session on that day below. The homework at the bottom of that page will be due the next day (as explained earlier). Remember that your username is the first initial of your first name and your last name, no caps and no spaces.

23 March2020 - Equilibrium Into
25 March 2020 - Examples 1-3 - General Process
27 March 2020- Examples 4-6 - Very Small/Very Large K
30 March 2020 - Examples 7-10 - Practice Equilibrium Charts
1 April 2020 - Acids/Bases and pH - General Acid/Base Concepts
3 April 2020 - More Equilib Examples - Weak Acid Equilibrium
6 April 2020 - Acid/Base Titrations I - Strong Acid/Strong Base
8 April 2020 - Acid/Base Titrations II - Weak Acid/Strong Base
13 April 2020 - Acid/Base Buffers - Common Ion Buffers

I may give an extra day if the page seems too long or hard, or I may add in some other things, but this is the schedule for now. Let me know if you have any questions.

25 March 2020

I thought we had another good conference session this morning where we went over the page for today and did another example on the "blackboard" of how to set up the tables that we will be using for equilibrium problems. Remember you can access the pages through our class webpage (where you get homework) using the link on the top right labeled “Equilibrium Site”. The direct url is http://studentworldteacher.net/courses/genChem/equilibrium/

A recording of part of today's session can be watched in the conference section of Canvas for this course. Click on the date and then on the presentation link that shows up under the date. It takes a while for it to show up, but it should be there by this afternoon. Part of the last session is also available.

There aren't a lot of students coming to these class sessions. I'm assuming the web pages are written well enough that you are getting it, but that seems like asking a lot. Please come to the sessions and ask questions. I actually enjoy going over the page and writing out other examples for you. I also think it will be helpful. You can listen to my voice go over some examples in the pink media boxes on the webpage, but they are somewhat limited and we can have more of a back and forth during the conference sessions. To join a session, go to Canvas, click on the Conference link, and join the current session. If you want to talk to me instead of typing questions in the chat area, you have to choose that option when you first sign in.

Keep up with these web pages and turn in the problems at the bottom of the pages on time. You should also look at the homework problems on our class webpage to make sure you understand everything.

Keep safe!

23 March 2020

I thought we had a good conference session this morning. I now have it set up so I can talk and write, like in class using the blackboard. I can also hear you if you set it up to talk when you log in. Like class, these sessions are not mandatory, but they may be very helpful going forward. I will be available during regular class times for these help sessions. By the way you can watch the part that I recorded by going into conferences and clicking on presentation.

Again, I have written web pages covering class "lectures" that you should study along with the book and the old homework from our class homepage. I have set up another category of assignments called "Homework" where I am putting the scores for the homework from these webpages. There are two points for each problem. In the end the scores will be assigned to quizzes. Just how is yet to be determined, but maybe something like a couple of webpages per quiz. You can do the page homework using the concepts from that page (and previous pages), so double check your answers before submitting.

The webpage homework will be due as explained in the last post. The Monday page is due on Tuesday, the Wednesday page is due on Thursday, and the Friday page is due on Monday. I will be marking them when they are late.

21 March 2020 - New Information

I have written web pages that cover my lectures. Each page has some questions for you to answer at the bottom of the page. Those questions will replace our quizzes. Monday questions will be due the next day, Tuesday, at noon. Wednesday questions will be due Thursday at noon. Friday questions will be due the next Monday before class at 8:30 am. Your username to use those pages is the first initial of your first name and your last name without any spaces or caps. Allison Smith would have the username asmith.

We will cover one of these pages each day that we would have met for lecture. You are to study the page and identify any questions you have. I will then be available in a conference session during our class time to answer those questions. Also, look at the regular homework problems where you have worked out solutions. They will help to clarify the concepts. You should also be using the textbook. It is excellent and is your resource for really understanding the concepts.

You can access the pages through our class webpage (where you get homework) using the link on the top right labeled “Equilibrium Site”. The direct url is http://studentworldteacher.net/courses/genChem/equilibrium/

For Monday, 23 March 2020, we will look at the first page on the menu labeled “Equilibrium Intro” during class time. You will then answer the questions at the bottom of that page and submit them before noon the next day. On Wednesday we will look at the second page “General Process” and you will submit the answers to those questions by noon on Thursday. And so on, doing the pages in order as we go down the menu. We will see how it goes and I will let you know if there is any change to the schedule. But for now, that is the plan. For purposes of the Registrar, submitting these questions will count as attendance.

In the lab we would have done the kinetics/color lab last week and you have some data for that lab. The calculations and result for that data is to be turned in by your lab time this coming Tuesday and Thursday. This week we were going to use the IR (infrared) spectrometer. I will have time next week to decide what we will do about that and the remaining equilibrium experiments. So, get everything that we have done in and then relax about the lab for a while.

I hope you and yours are staying healthy and that you are able to adapt to this new way of doing things. Let me know if I can help in any way.

19 March 2020 - Exam Update

I have now published the online exam. It will be available tomorrow (Friday) at 7:30 am and must be completed by 10:30 am. It will only be available during those times and you can only take it once. There is a copy of one page from Appendix C in the description section, but you can use your book if that is easier.

Because of the conditions we are working under, this can be considered a take-home exam. You can use materials available to you, but you should work independently and not consult anyone else.

18 March 2020 - Exam Update

I have decided that we will use a Canvas quiz to administer the exam on Friday. You will be required to show some work and put your answer into a text box. I will grade them as I usually do, giving partial credit when the work warrants it. Prepare for the exam the same way you would prepare for an in-class exam.

I suggest you write out your answers on a separate piece of paper as you would if taking it in class. Then transcribe the work and answers into the answer box. It doesn't have to look perfect, but be sure I can see how you did the problem and what your answer is. Since this may take some extra time, I will allow a total of three hours for this exam (7:30-10:30 am). You only get one attempt at this exam, so don't click submit until all of the questions have been answered.

The exam will cover everything we have done in class. Here is a list.

Understand what the rate expression is and be able to determine the order from the rate expression.
Be able to determine the rate law (expression) from experimental data.
Be able to use the mathematical equation for first order reactions (ln[a] - ln[a]_o = -kt).
Be able to determine and use the half-life.
Be able to draw and label potential energy diagrams.
Know how to get (from Appendix C) and use enthalpy (ΔH), entropy (ΔS), and Gibbs Free Energy (ΔG).
Be able to use ΔG = ΔH - TΔS and identify when reactions are spontaneous.

This week you should do the two problems given below (see 16 March, counts as our quiz this week) and hand in the corks lab. You can do the kinetics/color lab now, but it won't be late until next week.

I am now preparing web pages over the next material that will take the place of our class meetings. You will be required to read the pages and answer a few problems related to the page you are looking at. This shouldn't be too bad. We will still have quiz problems corresponding to the homework as well. More on all of this later.

Let me know if you have any questions.

17 March 2020 - New Lab For This Week

I took some data yesterday in order for you to complete this week's lab. It is a kinetics lab and should be good preparation for the exam on Friday. You don't need to write a complete lab report, just explain your work and show the result. Consider the numbers I gave to to be averages and you don't need to calculate a +/- for this report. You can access it from the right side of our class homepage or use http://studentworldteacher.net/courses/genChem/kineticsColor.htm.

16 March 2020 - Labs

I forgot to mention that the lab reports are still due this week. During this time I will accept attachments in Word or PDF format, but I still prefer it to be in the body of the email if possible. I will accept them from either lab section whenever you want to send it. You don't have to wait until the time your lab meets.

16 March 2020

Good morning and welcome to a new experience!

Just a quick note this morning with some general ideas that will be expanded upon later in the day and through the coming days.

We will keep with the schedule as stated in the syllabus. That means that this week we will be preparing for the exam on Friday. I'll give more details about the exam later, but prepare for the same kind of exam that we have had in the past. Going forward we will be using the book a lot more, but I will also give guidance about where to look and summarize the important concepts. More about that later.

Fortunately we finished all of the concepts for the exam last Friday in class. This morning I was going to go over a couple of problems from the back of the chapter to give some more exposure to these Gibbs Free Energy problems. I was specifically going to do 19.57 and 59c and d. I'll type them out here in case you are using a different edition of the book. Give them a try!

In fact I think we will use them as our quiz for this week. Try to write out the answers and let me know what kind of trouble you have getting the answers to me electronically. I have a couple of ideas, but I'll be interested to see what kind of solutions you come up with!

19.57 - For a certain chemical reaction, ΔH° = -35.4 kJ and ΔS° =-85.5 J/K. (a) Is the reaction exothermic or endothermic? (b) Does the reaction lead to an increase or decrease in the randomness or disorder of the system? (c) Calculate ΔG° for the reaction at 298 K. (d) Is the reaction spontaneous at 298 K under standard conditions?
19.59 - Using data from Appendix C, calculate ΔH°, ΔS° , and ΔG° at 298 K for each of the following reactions. In each case show that ΔG° = ΔH° - T ΔS°.
- (c) 2 PCl₃(g) + O₂(g) → 2 POCl₃(g)
- (d) 2CH₃OH(g) + H₂(g) → C₂H₆(g) + 2H₂O(g)

During this time I will start a conference session in Canvas when we would normally be in class. These are not mandatory, but they will give us a chance to chat if needed. I will start one now for today. I have started the conference, but I am in my office and don't have a microphone, so I can't talk. We can use the public chat section to communicate today.

This will be interesting, but we can get through it together!

24 February 2020

As explained in class, we will be doing a lab about the environment this week. See the class webpage for more details. Lab reports for the previous labs are now due and should be handed in this week. After this week they will be marked late.

See you in class on Wednesday!

19 February 2020

I received the following email from Maegan.

Sheehy, Maegan

This week I am only holding hours on Wednesday from 6:00-8:00 in the learning commons due to other things coming up during my normal hours. Suzanne wanted me to let you know so you can post an announcement on canvas informing the students. Thank you!

2 January 2020

Happy New Year!

I hope you all had a nice break and are ready for another exciting semester of chemistry. Just a note to everyone that we will be having lab during the first week of school.

I'll see you on Monday the 13th!

Chemistry at Work!

Welcome!

To get access to our class website, please follow this link.

Suggested Text: CHEMISTRY The Central Science, 12^th ed. by Brown, LeMay, Bursten, Murphy and Woodward
ISBN-10: 0-321-69672-7/ISBN-13: 978-0-321-69672-4 (Student Edition)
Optional text: Study Guide to accompany CHEMISTRY The Central Science

Use your regular Rivier email to contact me. Do not use Canvas conversations.

Thank you.

Dr. Burgess.