Introductory Chemistry

16 Jan 2020

Time-Integrated Rate Laws and the Stability of Gold(III) Anticancer Compounds

Submitted by Jack F Eichler, University of California, Riverside
Evaluation Methods: 

1) Performance on the pre-lecture online quiz

2) Performance on the in-class activity (clicker scores or hand-graded worksheet)

 

Evaluation Results: 

Students generally score on average 70% or higher on the pre-lecdure quiz, and on average 70% or more of students correctly answer the in-class clicker questions. 

Description: 

This is a flipped classroom module that covers the concepts of time-integrated rate laws. This activity is designed to be done at the end of the typical second quarter/second semester general chemistry kinetics unit. Students will be expected to have learned the following concepts prior to completing this activity:

a) how instantaneous rates of reactions are determined by measuring changes in concentration of reactants and/or products at the beginning of the reaction;

b) understanding basic rate laws and how rate laws are determined for a chemical reaction using instantaneous rates;

c) understanding why the rates of reactions slow down as the time of reaction increases.

Acknowledgement: This material is based upon work supported by the National Science Foundation under Grant No. 1504989. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

 

Learning Goals: 

Students are expected to achieve the following learning goals:

a) conceptually understand how time-integrated rates laws can be used to describe the kinetics of a chemical reaction;

b) use time-integrated rate laws to determine the rate constant for a first or second order reaction;

c) use time-integrated rate laws to determine the half-life of a decomposition reaction;

d) use Excel to plot time-integrated rate laws and generate best-fit linear trend lines.

 

Corequisites: 
Equipment needs: 

Students need a laptop or tablet device capable of operating a spreadsheet/graphing program. 

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

See attached instructor notes. 

Time Required: 
50-80 minutes
2 Jan 2020

Reaction Mechanisms: Energy Profiles and Catalysts

Submitted by Wesley S. Farrell, United States Naval Academy
Evaluation Methods: 

Students will report answers to the class.  The instructor should use the quality of these responses to gauge understanding.

Evaluation Results: 

N/A

Description: 

This in class activity consists of two demonstrations to be performed by the instructor, followed by a worksheet that students may work on independently or in groups.  The demonstrations allow the students to determine when a reaction has occured, when it has not occured, and generate qualitative reaction energy profiles to match these observations.  This activity is designed to take place during a description of kinetics in general chemistry. Detailed descriptions of the procedure and activity may be found in the "Overview for Instructor."

Learning Goals: 

Students should be able to create qualitative reaction energy profiles which match a series of reactions, catalyzed and uncatalyzed.

Subdiscipline: 
Equipment needs: 
  • Three 8” test tubes
  • 3% H2O2
  • Small cubes of potato, both raw and cooked
  • 250 mL Erlenmeyer flask
  • Pt spiral (preferably in glass tube with hook for support)
  • Methanol
  • Bunsen burner (with striker)

 

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

Please see the "Overview for Instructor" document for implementation notes.

Time Required: 
15 minutes
5 Dec 2019

Flipped Class Module - Lewis Structures of Industrially and Environmentally Relevant Molecules

Submitted by Jack F Eichler, University of California, Riverside
Evaluation Methods: 

1) Performance on the pre-lecture online quiz

2) Performance on the in-class activity (clicker scores or hand-graded worksheet)

 

Evaluation Results: 

Students generally score on average 70% or higher on the pre-lecdure quiz, and on average 70% or more of students correctly answer the in-class clicker questions. 

Description: 

This is a flipped classroom activity intended for use in a first semester general chemistry course. Students are expected to have prior knowledge in identifyng the difference between molecular and ionic compounds, understanding the conceptual framework for how covalent bonds form, and how to draw Lewis dot symbols for atoms, and how to determine the number of valence electrons for atoms.



The activity includes:

1) pre-lecture learning videos that guide students through learning how to draw valid Lewis structures, determining how to caculate the formal charge for atoms in molecular compuonds/Lewis structures, and using formal charge to determine which Lewis structure is most stable if multiple Lewis structures are possible for a given molecule;

2) pre-lecture quiz questions; and

3) an in-class activity that requires students to apply their knowledge of chemical bonding in drawing Lewis structures.

Acknowledgement: This material is based upon work supported by the National Science Foundation under Grant No. 1504989. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Learning Goals: 

Students should be able to:

a) draw Lewis structures of molecular compounds;

b) determine the formal charge of atoms in molecular compounds;

c) use formal charge to predict the most stable Lewis structure.

 

Equipment needs: 

Suggested technology:

1) online test/quiz function in course management system

2) in-class response system (clickers)

Course Level: 
Corequisites: 
Prerequisites: 
Implementation Notes: 

Attached as separate file. 

Time Required: 
50-80 minutes
18 Jul 2019

Science Information Literacy Badge--Reading the Literature

Submitted by Michelle Personick, Wesleyan University
Evaluation Methods: 

I use this activity as a "badge," which is self-paced guided skill-building activity that students complete on their own time outside of class. Badges are designed around fundamental chemistry skills that students wouldn’t necessarily acquire from standard course content and lectures. They carry a very small point value (about 2% of the course total per badge) but my students are very motivated by even small amounts of points. I assign points primarily based on completion and effort and also provide brief written feedback for each student. I have my students turn in badges in Moodle, which makes feedback more streamlined.

Description: 

This is an activity designed to introduce general chemistry students to reading the chemistry literature by familiarizing them with the structure of a published article. The activity first presents an article from the Whitesides group at Harvard about writing a scientific manuscript, along with a video about the peer-review process. There are two parts to the questions in the activity, which are based on a specific article from Nature Communications (doi.org/10.1038/s41467-019-08824-8). Part I is focused on the structure of the article and where to find key pieces of information. Part II encourages students to use general audience summaries in combination with the original article to best understand the science while making sure they get a complete and accurate picture of the reported work.

Prerequisites: 
Course Level: 
Corequisites: 
Learning Goals: 

A student should be able to approach the chemistry literature and determine where to find:

  • the authors and their affiliations;
  • the main objective of the research;
  • the main outcomes of the research;
  • why the research is important;
  • experimental details;
  • supplementary figures and other information. 

A student should be able to broadly evaluate the reliability of secondary summaries of scientific articles by comparing them against the key points of the original paper.

Implementation Notes: 

This activity is based on a specific article: "Room temperature CO2 reduction to solid carbon species on liquid metals featuring atomically thin ceria interfaces" (Nat. Commun., 2019, 10, 865. doi.org/10.1038/s41467-019-08824-8). However, it's easily adapted to other articles that are more suited to a particular course, and I've used other articles in previous iterations. This article was chosen because the content is at least partly accessible to students in my second semester general chemistry course, who have already had some electrochemistry/redox chemistry, and who have recently learned about kinetics, reaction mechanisms, and catalysis. The topic of liquid metals is new and interesting to the students, because it's not something the'd normally be exposed to, and the application to CO2 sequestration is something they can connect with. 

 

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
8 Jun 2019

VIPEr Fellows 2019 Workshop Favorites

Submitted by Barbara Reisner, James Madison University

During our first fellows workshop, the first cohort of VIPEr fellows pulled together learning objects that they've used and liked or want to try the next time they teach their inorganic courses.

8 Jun 2019

IUPAC Brief Guide to the Nomenclature of Inorganic Chemistry

Submitted by Robin Macaluso, University of Texas Arlington
Description: 

This is a short nomenclature guide designed to be used by students and faculty.

Subdiscipline: 
Topics Covered: 
Prerequisites: 
Corequisites: 
6 Jun 2019

VSEPR: Flash Review

Submitted by Christopher Durr, Amherst College
Description: 

This presentation is meant to be a review of applying VSEPRup to steric number 6. It's designed to be viewed as a powerpoint and printed out to keep for the student's notebook.

It can be used at multiple levels: as a review immediately after learning VSEPR in general chemistry, or as a refresher before starting upper level inorganic chemistry. The instructor could add text or voice over the slides to add more detail or leave the presentation as is for students.

If you'd like .psd or .pdf files of the drawings in these presentation, please contact me directly.

Prerequisites: 
Corequisites: 
Learning Goals: 

After reviewing this material students should be able to:

Draw the correct VSEPR predicted structure of a molecule based on steric number and lone pair count.

Name VSEPR structures with their appropriate geometry.

Avoid common VSEPR mistakes, particularly those with steric number 5 and 6.

Recognize how lone pairs distort bond angles from ideal geometry in molecules like ClF3

 

Implementation Notes: 

I plan on uploading this flash review (along with others) to my class site before students arrive to my upper level inorganic course. I will voice over the slides, explaining the concepts, so they're ready to apply molecular orbital theory on the first day of class.

Time Required: 
10 - 15 Minutes
Evaluation
Evaluation Methods: 

I will compare student preparedness between this class and a previous one that did not receive a review.

Evaluation Results: 

This will be updated in the future.

6 Jun 2019

Molecular Orbital Theory: Flash Review

Submitted by Christopher Durr, Amherst College
Description: 

This presentation is meant to be a review of constructing and utilizing an MO diagram, in this case O2. It's designed to be viewed as a powerpoint and printed out to keep for the student's notebook.

It can be used at multiple levels: as a review immediately after learning MO theory in general chemistry, or as a refresher before starting upper level inorganic chemistry. The instructure could add text or voice over the slides to add more detail or leave the presentation as is for students.

If you'd like .psd or .pdf files of the drawings in these presentation, please contact me directly.

 

 

Prerequisites: 
Corequisites: 
Learning Goals: 

After reviewing this material students should be able to:

Recall the shape, size and appropriate nodes of atomic orbitals.

Note the appropriate electron configuration of a given atom.

Draw molecular orbitals with the appropriate sign and node position.

Apply the Aufbau Principle to molecular orbitals to determine the ultimate spin state of a molecule.

Determine the bond order of a molecule from a completed MO diagram.

Manipulate the bond order of a molecule with Reduction/Oxidation.

 

Implementation Notes: 

I plan on uploading this flash review (along with others) to my class site before students arrive to my upper level inorganic course. I will voice over the slides, explaining the concepts, so they're ready to apply molecular orbital theory on the first day of class.

Time Required: 
10 - 15 Minutes
Evaluation
Evaluation Methods: 

I will compare student preparedness between this class and a previous one that did not receive a review.

Evaluation Results: 

This will be updated in the future.

31 May 2019

Helping Students with Visual Impairments See Colors

Submitted by Douglas Balmer, Warwick High School
Evaluation Methods: 

Do these students identify the same colors as the students without visual impairments?

Are their lab results correct? 

Evaluation Results: 

Students were able to accurately describe colors.

Description: 

I have had some students in class have a hard time identifying colors (flame tests, solution color, acid-base indicators, etc.) because of a visual impairment. There are many cell-phone apps that are helpful in aiding these students. "Pixel Picker" allows the students to load a picture from a device (cell phone, ipad). This is helpful because students are now dealing with a "frozen" image. Moving the cross-hair to different parts of the picture changes the R-G-B values. The "Color Blind Pal" app uses a more qualitative approach. It names the color in the cross-hair using various color scales. There are also different options for different types of color blindness. 

Both of these apps are free and availble in the App Store.

Prerequisites: 
Corequisites: 
Course Level: 
Learning Goals: 

A student should be able to correctly identify an unknown metal by the color of its flame.

A student should be able to correctly identify the endpoint in a titration by the indicator's color change.

A student should be able to correctly describe the physical properties (color) of a sample.

A student should be able to correctly predict the visible absorbance spectrum of a solution based on correctly identifying the color of the solution.

Implementation Notes: 

Have the students with visual impairments practice using the app ahead of time to better prepare them to use the app for the first time in class/lab. Students would also need to understand the additive nature of light colors. For example, high R and G values will appear yellow/orange. I would give these students a 1-page handout for their lab notebook with the addative color wheel and various colored circles labeled with their names and RGB values so that students could practice and reference in the lab.

Our lab safety contract actually has students indicate whether they are color blind. This is a good time to introduce these students to the apps.

Time Required: 
15 min

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