mathematics

JCE 95.10 October 2018 Issue Highlights

The Human Side of Teaching and Learning

The October 2018 issue of the Journal of Chemical Education is now available to subscribers. Topics featured in this issue include: research on: AP chemistry reform and writing instruction; novel teaching approaches; demonstrations: safety and effectiveness; augmented reality and technology for teaching; using stories and history to teach; exploring acid-base chemistry; understanding energy; biochemistry in the laboratory; teaching resources; astrochemistry resources for National Chemistry Week 2018.

JCE 95.08 August 2018 Issue Highlights

Relevant Topics for Instruction and Assessment

The August 2018 issue of the Journal of Chemical Education is now available to subscribers. Topics featured in this issue include: the chemistry of candy and sugar, examining virtual learning for laboratories, strengthening student understanding of acid-base chemistry, building scientific communication skills, emphasizing learning, sustainability and green chemistry, cost-effective resources and techniques, laboratory investigations, ConfChem conference on mathematics in undergraduate chemistry instruction, erupting from the archive: soda geysers.

JCE 95.05 May 2018 Issue Highlights

The May 2018 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: electrochemistry and corrosion; textbooks; research on the chemistry teacher pipeline, argument-driven inquiry, and online homework; using everyday objects to teach; teaching organic chemistry with games; communication and writing; examining and creating innovative curriculum; computer-aided discovery activities; exploring kinetics; interdisciplinary laboratory investigations; from the archives: applications of 3D printing for teaching chemistry.

Stoichiometry is Easy

This article describes a three week lesson plan for teaching stoichiometry using an algorithmic method. Two labs (one designed as a laboratory quiz) several cooperative learning exercises, student worksheets and guided instructional frameworks (forcing students to develop good habits in writing measures and doing problem solving) are included. The highlight of the lessons is the "chemistry carol" (based on Felix Mendelssohn's music for "Hark! The Herald Angels Sing") in which students recite a five-step algorithm for completing stoichiometry problems. While algorithmic processes may not always be best, I have found that there are many benefits to giving students a firm background and something to always fall back upon in one of the more challenging topics of chemistry. I believe that the good habits developed in this method of stoichiometry carry through to all the rest of their chemistry work, making it much easier to use inquiry-based methods when doing other advanced chemistry topics.

Writing Conversion Factors

This worksheet is intended to be used as a "Guided Instructional Activity" (GIA). Students read a statement that gives a either a conversion factor or a pair of related measures and then write the information as two equivalent fractions ("conversion factors") and as an equality. In each representation, students are directed to give the numeral of the measure, unit, and identity of the chemical.

Time required: 

35 to 45 minutes.

Mole Conversion Guided Instructional Activities

The three "Guided Instructional Activities" in this activity are three cooperative learning pieces in which students are guided through the process of converting from one unit to moles (or moles to a unit) by the method of "unit analysis" (dimensional analysis). Students alternate steps in the process and evaluate the success of each step. They must do things such as writing the given information correctly, finding the correct molar mass, setting up the mathematics correctly, and determining the answer to a required number of significant figures.

Time required: 

Each of the activities requires about 40 to 55 minutes. The first one used usually takes longer, the last goes quicker.

Mole Conversions: 1- & 2-step with format

This worksheet asks students to do basic conversions of mass or molecules to moles and vice versa. The worksheet requires students to complete their work in a particular format and to inlcude number, unit, and chemical identity for each item in the "given," in each conversion factor, and in the answer. It gives students basic practice in this mathematical exercise while inforcing good habits that encourage "unit analysis" (or dimensional analysis).

Time required: 

This worksheet can be used as an in-class or as a homework assignment. The ten items on the first page should take 20 to 30 minutes. The ten items on the second page should take 30 to 50 minutes.

Finding and Writing the Molar Mass of Elements [corrected]

This worksheet is intended to be used as a "Guided Instructional Activity" (GIA). It asks students to find the molar mass of selected elements and write the molar mass as two equivalent fractions ("conversion factors") and as an equality. In each representation, students are forced to give the numeral of the measure, unit, and identity of the chemical.

Time required: 

About 45 minutes.