Acid-base chemistry

15 May 2020

Inorganic Active Learning Lesson Plan Design

Submitted by Meghan Porter, Indiana University
Evaluation Methods: 

I use the rubric provided, combined with the peer review feedback (due to COVID, they did not have the chance to revise after the peer review process).  Students must also upload a key with their activity which allows me to catch any misconceptions or inaccuracies in their understanding of the material.

I assigned points as following:

Assignment/Key: See above rubric

Reflection: Worth 5 points total- while mostly graded on completion, I did want to be sure my students were providing more useful feedback than 1 word answers so I gave them the rubric below. (pretty much everyone got a 5)

Completed Reflection

5

3

1

What did you learn from completing this assignment? (i.e. What do you feel that you gained from completing it?)

What did you learn from completing other students' assignments?

What are your thoughts for improving the active learning lesson plan assignment in future iterations?  You may answer this referring to your specific lesson plan or this actual assignment of creating a lesson plan.

 

Meets all criteria at a high level, all questions are thoughtfully addressed

Meets some criteria, some questions are not addressed or non-thoughtful response provided

Meets few criteria, most questions not addressed or responses do not demonstrate thought

Peer Review: Spring 2020 was my first time doing the peer review, and of course covid definitely changed the way I had planned on completing it.  My plan was to have them exchange activities in class or in recitation, work through them in small groups, then be able to provide feedback.  Instead, they had to complete it online and provide feedback- I gave them the basic rubic, but changed the scores to categories of "exceeds expectations", "meets expectations", and "does not meet expectations".

Evaluation Results: 

I am always blown away by the creativity of my students!  While some students submit more group worksheet activities, I have had plenty come up with games, relays, building/using playdough, etc...

Students usually report that they thought they knew a topic- only to begin making an activity and realize they didn't understand it as well as they thought they did.  However, by the time the submitted their activity, they felt like they gained a much more in-depth understanding.  They also loved getting to complete other students' assignments this semester.  Their feedback indicated that they felt it was a great way to review, but also get some insight into how their peers think differently about topics.

Side note: Personally, I love seeing how many students tell me afterward that they have a newfound respect for professors after trying to make their own activity! :-)

Description: 

I created this activity as a way to get the class involved in creating new, fun ways to teach course concepts (selfishly- that part is for me) and for students to review concepts prior to the final exam (for them).  Students use a template to create a 15-20 min activity that can be used in groups during class to teach a concept we have learned during the semester.  We then randomly assign the activities and students work in groups to complete them and provide feedback.

The benefits are twofold:

1. My class is about 100-150 students per semester.  This means that each semester I have a large number of new activities (that I didn't have to make!) to use as a starting point in future semesters as I work to create a more active classroom.

2. The students get a review of the topic they have chosen for their activity, plus, they get to review additional topics from completing and providing feedback on two activities from their peers.

I have run this assignment for three semesters now.  It has been a favorite of my students since the beginning!  I have received a number of activities that I now use in class to teach topics!

Learning Goals: 

A student should be able to

  • Create a lesson plan on an inorganic topic that incorporates active learning
  • Demonstrate understanding of chosen topic via an accurate lesson plan key
  • Review multiple inorganic topics through completion of lesson plans from classmates
  • Provide constructive feedback on classmates’ completed lesson plans

 

Equipment needs: 

None

Corequisites: 
Prerequisites: 
Implementation Notes: 

Since this can be used for any level or any topic, there are plenty of variations you can try!  Some things to consider:

1. You can allow students to select any topic from the entire semester for their activity- this can be helpful prior to a final exam when you want a comprehensive review.  You can also restrict topics if you have areas that you feel your students need to focus on or if you want to assign this before a specific exam.  One of my students also suggested having a sign up sheet for topics on a first-come, first-served basis so that you don't end up with 20 balancing redox reactions and zero crystal field splitting.

2. I have tried students designing plans individually and also working in partners to create acitivties (both outside of class).  Both methods worked well, but in a class of 150, that many individual submissions to grade was a bit overwhelming!

3. The peer review was new this semester (based on a previous student suggestion).  My original plan was have them use a recitation section to work in groups through randomly assgined activities.  Due to COVID, they completed the activites on their own- they enjoyed it, but the group experience would ave been more fun.

4. Depending on your timing, you could have them go through the peer review process and then give them a chance to revise the activity based on the feedback prior to you grading it.

5. The student reflection questions are given as a survey on Canvas after they have completed both the lesson plan and the peer review process.

19 Mar 2020

Job's Method - The Covid-19 Version

Submitted by Chip Nataro, Lafayette College
Evaluation Methods: 

Students are generally asked to write a full lab report including an abstract, brief introduction, experimental and results/discussion. I will likely not ask them to do that in this virtual lab. However, they will be asked to determine the value for n for the various [Ni(en)x] solutions as well as questions 1 and 2 from Angelici's book. In addition, I typically ask them to do some literature searching questions, but I am not sure if they will have access to SciFinder so I may have to bypass that or provide them the original papers I have them look at. Links to those papers are included.

Evaluation Results: 

I'll use this in a few weeks and see how it goes.

Description: 

This is the classic Job's Method experiment from "Synthesis and Technique in Inorganic Chemistry" 2nd Ed. (1977 or 1986 pp 108-114) by R. J. Angelici. There are slight changes from the experiment published in the book but they just include running solutions with ethylenediamine mole fractions of 0.67 and 0.75, so details will not be provided. What is provided are a series of pictures and videos showing the experiment being performed. Also included are the raw files of the absorbance spectra in EXCEL. It is not perfect but given the situation many of us are facing at the time this is published, it is better than nothing.Note that this lab was updated on 4/4/2020. The previous data was terrible. New solutions using a fresh bottle of ethylenediamine were prepared. The two solutions mentioned previously were also included. The data is much better. The worked up data has also been included in the instructor only files.

My apologies to my coauthors who spent way too much time looking over the original data set and trying to make sense of it. Their thoughts and insight led to this update. My sincere apologies to anyone else that scuffled over the original data.

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

A student should get an appreciation for what doing this lab would be like by watching videos. In addition, the student will analyze the data provided and determine the species present in solutions containing various mole fractions of ethylenediamine and Ni(II).

Equipment needs: 

Nothing

Implementation Notes: 

Like most everyone at this time this is going to be a trial by fire.

9 Jan 2020

Marvin suite from ChemAxon

Submitted by Anthony L. Fernandez, Merrimack College
Evaluation Methods: 

As my students draw structures, I usually observe them and make suggestions to improve their drawings. 

Evaluation Results: 

While I do no formal assessment of this activity, I have observed that students seem to learn how to use the program fairly quickly and then use it without much difficulty for the rest of the semester.

Description: 

It is important for students to be able to effectively communicate the results of their scientific work. This does not only inlcude written and oral communication, but the creation of appropriate representations of the complexes they have investigated. It is crucial that students learn how to draw molecules using electronic structure drawing programs, but site licenses for structure drawing programs can be prohibitive for some institutions.

Marvin suite is a software package from ChemAxon that is freely avaialble for educational institutions. It contains a structure drawing program (MarvinSketch) and a viewer (MarvinView), as well as tools that allow for the calculation of many molecular and spectroscopic properties of molecules. This is a very useful suite of programs that can be used by all students and faculty at an instituion once an Academic License is obtained.

A set of directions for drawing a coordination complex in MarvinSketch is also included as part of this learning object. These directions will guide the user as they draw the structure of a square-planar coordination complex, trans-[Ni(NCS)2(PMe3)2].

Corequisites: 
Prerequisites: 
Learning Goals: 

After following the instructions, students should be able to draw a chemical structure electronically using a chemical structure drawing program.

Once the structure in drawn in the program, a user would then be able to access the many other functions available in the software.

Implementation Notes: 

During the first week of our semester, lab sections are usually not held for courses so that student enrollment issues can be sorted out. In an advanced course such as Inorganic Chemistry, I want to take advantage of every week that I can so I use the first lab meeting time to have students learn how to use several software programs that they wil use over the course of the semester. 

I post the download link and the license file for the software on the course LMS before the lab period and I ask the students to download and install the software. You should make sure that students update their Java installation before installing the Marvin suite. (I also place a link to the Java download site on the course LMS as well, but students tend to ignore it.) Aside from the Java issue, I have found that there are no real issues encountered by students when they install the software. 

When we meet, I ask the students to follow the linked instructions to create a drawing of a coordination complex. Once they complete that successfully, I ask them to draw several other structures. I do not  have any specific structures that I use, but I try to choose complexes with different geometries (octahedral, tetrahedral, square pyramidal, etc.) around the metal center.

The Marvin suite of programs provides the students with a number of useful tools, not just a structure drawing progam. Students use this to calculate or estimate a number of different things, such as the molecular mass, the elemental analysis, a mass spectrum, 1H and 13C NMR, and charge distribution.

To obtain a license file, the faculty member must log into the ChemAxon site and request an Academic License. Once approved, the instituion is allowed to use the software for 2 years and the license can be easily renewed when it expires.

 

Time Required: 
30 minutes
9 Oct 2019

2019 Nobel Prize - Li-ion battery LOs

Submitted by Barbara Reisner, James Madison University

Congratulations to the 2019 recipients of the Nobel Prize - John B. Goodenough, M. Stan Whittingham and Akira Yoshino. It's a well deserved honor!

There are several LOs on VIPEr that talk about lithium ion batteries and related systems. The 2019 Nobel is a great opportunity to include something about these batteries in your class.

I hope to see more LOs in the coming weeks so we can bring this chemistry into our classrooms!

Prerequisites: 
Corequisites: 
29 Jul 2019

Introduction to Drago's ECW Acid-Base Model

Submitted by Colleen Partigianoni, Ferris State University
Description: 

This LO was created to introduce Drago’s ECW model, which is an important contribution to the discussion of Lewis acid-base interactions. Unlike the qualitative Pearson’s HSAB model (Hard Soft Acid-Base model,) the quantitative ECW model can be used to correlate and predict the enthalpies of adduct formation and to obtain enthalpy changes for displacement or exchange reactions involving many Lewis acids and bases.  Unlike all other acid-base models, graphical displays of the ECW model clearly show that there is no one order of acid or base strengths, and illustrate that two parameters are needed for each acid and base to provide an order of acid or base strength.  The ECW model can also provide a measure of steric strain energy or pi bonding stabilization energy accompanying adduct formation, which is not possible with any other acid-base model. 

This set of slides is intended to provide a basic introduction to the model and several examples of predicting energy changes using the model. It also illustrates how to construct and interpret a graphical display of the model.

 It should be noted that this LO is not in the PowerPoint format, but instead is a more extensive set of notes for instructors who are not familiar with the ECW model. It could be condensed and rewritten in the more standard PowerPoint format.

There is also an ECW problem set LO that can used to supplement this LO.

Prerequisites: 
Corequisites: 
Learning Goals: 

After viewing the slides, students, when provided with appropriate data, should be able to:

  • Calculate sigma bond strength in Lewis acid-base adducts using Drago’s ECW model.
  • Show how to deal with any constant energy contribution (W) to the reaction of a particular acid (or base) that is independent of the base (or acid) when an adduct is formed.
  • Garner information regarding steric effects and pi bond stabilization energy in Lewis acid-base adducts using the ECW model.
  • Show using a graphic display of ECW that two parameters for each acid and each base are needed in acid-base models to determine relative strengths of donors and acceptors.
Evaluation
Evaluation Methods: 

This LO has not been used yet and evaluation information will be posted at a later date.

25 Jul 2019

1FLO: One Figure Learning Objects

Submitted by Chip Nataro, Lafayette College
Corequisites: 
9 Jul 2019

Constructing a Class Acid-Base Titration Curve

Submitted by Katherine Nicole Crowder, University of Mary Washington
Evaluation Methods: 

Students were allowed to keep working until they had correct pH values, so they were graded on participation. Worksheets were collected at the end in order to construct the titration curve.

This could be collected and graded for correctness.

 

Evaluation Results: 

Students were evaluated on similar questions on the subsequent exam. Most students (12 out of 15) scored 11-13 points on a 13 point question where they had to solve for the pH in the four regions of a strong acid titration curve. 8 out of 15 recieved full credit on a question where they had to calculate the pH in the buffer region of a weak acid titration curve.

Description: 

In this in-class activity, each student calculates the inital pH, equivalence volume, and pH at the equivalence point for both a strong acid-strong base and a weak acid-strong base titration.

In addition, each student is assigned a unique volume before the equivalence point and a unique volume after the equivalence point for each titration curve.

The data from the class is then assembled in Excel to construct the two titration curves.

This forces each student to do the calculations for each of the four regions of both types of titration curves. This activity could be used to introduce titration curves or to reinforce previously covered lecture material/problem-solving. It could also be switched to do a strong base-strong acid or a weak base-strong acid titration curve.

The constructed titration curves can be used for further discussions of the differences between a strong acid and a weak acid in terms of initial pH, the rapid-rise portion of the curve, and the pH at the equivalence point.

 

 

Learning Goals: 

A student should be able to

  • determine the pH of a strong acid solution
  • determine the pH of a weak acid solution using Ka
  • use stoichiometry to calculate equivalence volumes for acid-base titrations
  • employ limiting reagent calculations to determine acid or base concentrations for different regions of a titration curve and determine pH
  • determine the pH of a weak base solution using Ka, Kb
Subdiscipline: 
Equipment needs: 

notecards with assigned volumes

computer for entering volume and pH data

Course Level: 
Corequisites: 
Prerequisites: 
Topics Covered: 
Implementation Notes: 

This could be done as an in-class activity (I used a 3 hr lab period - most students took less than 2 hrs) or as a take-home assignment. Students were allowed to use their notes and textbooks. I did not strictly forbid them from working together, but I did tell them that I wanted them to be sure that they could do all of the calculations themselves.

I had an Excel spreadsheet of the correct pH values for each volume (attached). Students were allowed to come check their work with me and continue working if their answers were incorrect. I was also able to help them if they got stuck.

 

Attached are the student worksheets, the class titration curves, and the Excel file I used to calculate the correct pH values. I chose volumes and molarities that would give me an appropriate number of volumes before the equivalence point. Volumes and molarities should be adjusted as needed for the size of your class.

I used whole number volumes, but I think it would be better to have smaller volume increments near the rapid-rise portions of the curves so it doesn't look like the data "jumps" as much.

Time Required: 
1-2 hr

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