General Chemistry

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.

2 Jun 2019

Maths for Chemists

Submitted by David Harding, Walailak University
Description: 

Chemistry requires mathematics in almost all areas but it is a subject many students struggle with. This short booklet introduces mathematics from basic concepts to more advanced topics. A particularly nice feature is that examples of chemistry calculations are included so that students can understand why they have learn mathematics at all. This resource comes from the Royal Society of Chemistry's Learn Chemistry website.

Prerequisites: 
Corequisites: 
Course Level: 
6 May 2019
Evaluation Methods: 
  • The instuctor walked around the classroom to help students individually as needed for immediate assessment.
  • At the end of the class period, students submitted their work to Blackboard for grading.
  • Assignments were graded based on accuracy and quality of the drawings.
Evaluation Results: 

Students generally were able to determine the molecular formula and generate connectivity drawings of the displayed 3-D structures, but really struggled with 3-D drawing. Although this was developed for a course with second year students who had completed general chemistry, even older students in the course struggled with this component. However, by the end of class, all students greatly improved in their ability to understand, interpret, and convey 3-D structure. 

Many students were surprised and many jokes were made about this being a chemistry art class. Although some students didn't particularly enjoy drawing, all understood the value and felt like they had learned something useful. At the end of the semester, many students remarked that the chemical drawing section was the most useful or interesting. 

Description: 

This in-class activity was designed for a Chemical Communications course with second-year students. It is the first part of a two-week segment in which students learn how to use Chemdraw (or similar drawing software) to create digital drawings of molecules.

In this activity, students are given a blank worksheet and 5 models of molecules were placed around the classroom. Students interpreted the 3-D models to determine molecular formulas, connectivity, and generate drawings that convey the 3-D elements. Once students completed the worksheet by hand, they generated the whole worksheet using Chemdraw.

Learning Goals: 

Students will be able to:

1.    Write the formula for a molecule based on a 3-D structure.

2.    Draw a molecule based on a 3-D structure.

3.    Convey 3-D structure of a molecule in a drawing.

4.    Translate molecular connectivity to a drawing that conveys 3 dimensions.

5.    Create digital drawings of molecules using Chemdraw or similar chemical drawing software.

Equipment needs: 
  • Molecular model set for the instructor to prepare structures before class.
  • One computer per student with chemical drawing software such as Chemdraw.
Course Level: 
Implementation Notes: 

Prior to the activity, students were given a brief presentation with an introduction to basic Chemdraw elements using the Chemdraw manual and existing tutorials (see links provided). VSEPR was also reviewed.

For the activity, students were given 3-D models of molecules, and the color key for atom identity was written on the board (eg. blue = oxygen, black = carbon...). The activity was conducted in a class of 24 students, in which each student had access to a computer. The entire class period was 1 hour 50 min, but the activity could be shortened if fewer molecules are included.

Before class, the instructor built models of molecules using a molecular model kit. It is helpful to have multiple copies of each molecule, especially for a larger class, but not critical. The molecules used for the acitvity can be seen in the faculty-only key, and were chosen to have a range of 3-D structures, but other molecules could be chosen. For example, a coordination chemistry or upper division course could have 3-D printed models of crystal structures used as the starting point. 

Time Required: 
60 min
12 Feb 2019

Advanced ChemDraw (2019 Community Challenge #2)

Submitted by S. Chantal E. Stieber, Cal Poly Pomona
Evaluation Methods: 

Students were evaluated during class for effort and participation, and the instructor gave immediate tips and feedback. After students submitted the assignment, it was graded for completion and effort.

 

Evaluation Results: 

Students were allowed to turn in the assignment 2 days later and 22/24 students completed the assignment. The most common errors were slight variances in bond angles and missing colors used in the literature figures. Overall, the quality of the submitted work was impressive, especially for second-year students.

Description: 

This in-class activity was designed for a Chemical Communications course with second-year students. It is the second part of a two-week segment in which students learn how to use ChemDraw (or similar drawing software to create digital drawings of molecules).

In this activity, students learn advanced techniques to visualize complex organometallic molecules and reaction schemes using ChemDraw. Students are presented with several images and reaction schemes taken directly from the organometallic literature and are tasked with recreating the images using ChemDraw. This gives students direct exposure to current literature, while learning useful skills in chemical visualization.

Learning Goals: 

Students will be able to:

1.    Convey 3-D structure of a molecule in a drawing.

2.    Recreate molecular drawings found in the literature.

3.    Create digital drawings of molecules using ChemDraw.

4.    Create digital drawings of reaction schemes & cycles.

Equipment needs: 

Computer for each student with ChemDraw installed.

Implementation Notes: 

This was implemented in a 24-student course in the week following an introduction to basic ChemDraw use. Students were shown the techniques in lecture format using the attached Powerpoint presentation. After the presentation, students had access to the slides and could refer to them while completing the activity. 

In-class most students were mostly able to complete the worksheet using the powerpoint slides as a guide. However, the instructor also walked around to give individual tips and instruction. 

The total time for the activity and lecture was 1 hour 50 min, but it could be shortened or assigned for homework.

In the section where students are asked to interpret molecular formulas, this is done ignoring ligand abbreviations, such as R groups or simplifications of chelating ligands. This could be left off, however it was a useful way to introduce students to drawing simplifications they may find in the literature. Most students just interpreted the formula based on what was drawn, and some students looked up the original papers to get a more accurate formula (although this takes much more time). 

 

Time Required: 
60-110 min
17 Nov 2018

Quantum Numbers and Nodes: A General Chemistry Flipped Classroom Module

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 quantum numbers, and radial and angular nodes. This activity is designed to be done at the beginning of the typical first quarter/first semester general chemistry course (for an atoms first approach; if instructors use a traditional course structure this unit is likely done towards the middle/end of the first quarter/semester). Students will be expected to have learned the following concepts prior to completing this activity:

a) quantization of energy in the atom and the Bohr model of the atom;

b) how the wave/particle duality of electrons was described by de Broglie;

c) how the wave/particle duality of electrons was used by Schrodinger to develop the quantum mechanical model of the atom;

d) how radial probability distribution was used to generate the idea of atomic orbitals, and orbital probability surfaces.

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: 

a) describe the meaning of the quantum numbers n, l, and ml;

b) determine the values of the quantum numbers n, l, and ml;

c) describe the meaning of radial and angular nodes;

d) determine the number of radial and angular nodes on different types of atomic orbitals;

e) begin to understand the correlation between the quantum numbers and the total number of atomic orbitals for a given atom, and how the periodic table can be used to build up the overall orbital structure for an atom.

 

Equipment needs: 

Suggested technology:

1) online test/quiz function in course management system

2) in-class response system (clickers)

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

Attached as separate file. 

Time Required: 
50-80 minutes
22 Oct 2018
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-lecture quiz, and on average 70% or more of students correctly answer the in-class clicker questions. 

 

Description: 

This is a flipped classroom activity that is intended for use in a college-level first semester/first quarter general chemistry course, and aims to provide a real-world context for thermochemistry concepts by focusing on the problem of producing hydrogen fuel in a sustainable manner. Current industrial production of hydrogen relies on extracting hydrogen from hydrocarbon molecules. Producing hydrogen in this manner brings about the obvious problem of relying of fossil fuels for a “sustainable” fuel. In this activity students will become familiar with the advantages and disadvantages of using water as a source for hydrogen, learn how steam reforming of ethanol is being used as a hydrogen source, and will use enthalpy calculations to compare the thermochemical properties of these different reactions.

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: 

a) using standard heats of formation to calculate the enthalpy for reactions;

b) comparing the enthalpies of different reactions and evaluating which reactions are more spontaneous from a thermochemical standpoint;

c) evaluate different reactions used to produce hydrogen fuel for use in fuel cell vehicles based on the enthalpy of the reactions;

d) gaining appreciation for research that aims to develop methods of producing sustainable fuel sources and why researchers and/or policy makers would be interested in developing sustainable fuel sources.

 
Equipment needs: 

Suggested technology:

1) online test/quiz function in course management system

2) in-class response system (clickers)

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

See attached instructor notes. 

Time Required: 
50-80 minutes
17 Jul 2018

Stoichiometric Calculations: A General Chemistry Flipped Classroom Module

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. As  noted in the worksheet answer key, question #4 generally gives students the most trouble as they may not yet have learned how to sum a series of reactions to yield an overall reaction. Instructors are encoruaged to do an example of this in the acitivty introduction. 

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 determining the molar mass of compounds, how to carry out mole/gram conversions, and how to write balanced chemical reactions. The activity includes:

1) pre-lecture learning videos that guide students through carrying out basic stoichiometric calculations, determining the limiting reactant, and determining the percent yield of a reaction;

2) a pre-lecture interactive tutorial that helps students learn the concept of limiting reactant;

3) pre-lecture quiz questions; and

4) an in-class activity that requires students to apply their knowledge of stoichiometry and limiting reactant in the real-world application of converting coal to liquid fuel.

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 complete the following learning objectives:

a) using mole-gram conversions and mole-mole conversions to carry out stoichiometric calculations for balanced chemical reactions;

b) gaining appreciation for how stoichiometric calculations are used in real-world chemical reactions.

Prior to completing this activity, students will be expected to have learned how to use molar masses of elements and compounds to carry out mole-gram conversions, how to balance chemical reactions, and how to use balanced chemical reactions to carry out mole-mole conversions.

 

Equipment needs: 

Suggested technology:

1) online test/quiz function in course management system

2) in-class response system (clickers)

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

Attached as separate file. 

Time Required: 
50-80 minutes
22 Jun 2018
Evaluation Methods: 

Discuss students responses with respect to the answer key.

Evaluation Results: 

This activty was developed for the IONiC VIPEr summer 2018 workshop, and has not yet been implemented.

Description: 

Inorganic chemists often use IR spectroscopy to evaluate bond order of ligands, and as a means of determining the electronic properties of metal fragments.  Students can often be confused over what shifts in IR frequencies imply, and how to properly evaluate the information that IR spectroscopy provides in compound characterization.  In this class activity, students are initially introduced to IR stretches using simple spring-mass systems. They are then asked to translate these visible models to molecular systems (NO in particular), and predict and calculate how these stretches change with mass (isotope effects, 14N vs 15N).  Students are then asked to identify the IR stretch of a related molecule, N2O, and predict whether the stretch provided is the new N≡N triple bond or a highly shifted N-O single bond stretch.  Students are lastly asked to generalize how stretching frequencies and bond orders are related based on their results.

 
Learning Goals: 
  1. Evaluate the effect of changes in mass on a harmonic oscillator by assembling and observing a simple spring-mass system (Q1 and 2)

  2. Apply these mass-frequency observations to NO and predict IR isotopic shift (14N vs. 15N) (Q3 and 4)

  3. Predict the identity of the diagnostic IR stretches in small inorganic molecules. (Q5, 6, and 7)

Equipment needs: 

Springs, rings, stands, and masses (100 and 200 gram weights for example).

 

Corequisites: 
Implementation Notes: 

Assemble students into small groups (2-4) discussions to answer the questions to the activity and collaborate.

 

 

Time Required: 
Approximately 50 minutes
19 Dec 2017

Visual scaffold for stoichiometry

Submitted by Margaret Scheuermann, Western Washington University
Description: 

These five slides are intended to share a visual scaffolding that I developed to help my general chemistry students identify what calculations are needed to solve stoichiometry problems.

 

The visual scaffold involves writing the balanced equation and then under it drawing a table with two rows and enough columns so that there is one column under each reagent in the equation. The top row is labeled as "moles" and the bottom row is labeled as "measurable quantity". Students then write in any information about a specific reagent or product that was given and identify the quantity that the question is asking them to find. They then add a series of arrows to the table to generate a "map" of how to get from the information they are given to the information they need to find with each arrow representating a type of calculation that they have already seen and practiced. Vertical arrows represent a calculation between a measured quantity and a number of moles. Horizontal arrows in the top row represent calculations between moles of one substance and moles of another substance. Horziontal arrows in the "measured quantity" row are not allowed since those unit conversion factors are not readily available. 

 

Corequisites: 
Topics Covered: 
Prerequisites: 
Course Level: 
Learning Goals: 

A student should be able to determine the quantity of a reagent required or the quantity of a product produced in a reaction.

Subdiscipline: 
Related activities: 
Implementation Notes: 

The scaffolding begins with a review of the two types of calculations that are required for basic stoichiometry: converting between grams and moles, and converting between moles of one substance and moles of another substance using the coefficients of a balanced equation as unit conversion factors (slide 1).

Some ABCD card/clicker questions can be added here if students have not practiced these types of problems in class recently.

After introducing the visual scaffold (slide 2) I do an example problem or two on the board/overhead/doc cam (slide 3).

This is a good point to give students an opportunity to work on a practice problem or if the introduction to stoichiometry began part way through a class period, an exit question.

Next I introduce situations where it could take more than one calculation to get from the measured quantity to moles (slide 4). 

An example problem and/or practice problem and/or exit question can be added here.

The visual scaffold is also relevant for limiting reagent problems. I've included an example (slide 5/6) but limiting reagent is usually presented in a subsequent class period after some examples of the limiting reagent concept using sandwiches or something similar. 

Time Required: 
30-50 minutes. varies with the number of examples and practice problems
Evaluation
Evaluation Methods: 

I will usually do an exit question- a stoichiometry problem from the textbook- after either slide 3 or slide 4. I do not require students to use the visual scaffold if they are already comfortable with stoichiometry from a previous class but many choose to use it. Some students will include the tables from the visual scaffold as part of the work they show on exams, again without being prompted or required to do so. 

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