xkcd is a nerdy Internet daily cartoon that is written and drawn by a former NASA "roboticist". The subject matter is all over the map [yesterday's (11/4/14) is about TypographicChemistry], but tends to favor physics and computing. He encourages readers of the cartoon strip to send him outrageous questions, and he supplies outrageous but scientifically accurate responses. Some of the best of these have be come a surprising NYT Best Seller.
JCE ChemEd Xchange provides a place for sharing information and opinions. Currently, articles, blogs and reading lists from ChemEd X contributors are listed below. We plan to include other items that the community wishes to share through their contributions to ChemEd X.
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.
About 45 minutes.
Given the amount of one reactant, students must use stoichiometry to find the ideal amount of the second reagent to use to create purple fireworks. The teacher ignites each groups' fireworks. Ideal mixture create little or no ash. Student assignment sheet with directions (and different initial amounts) plus teacher information and sample answers are included. This is an exciting and engaging activity that can be used as a stoichiometry quiz.
With one balance per table (two groups), the calculations should take about 10 minutes, the measures another 10 minutes. Ideally, students should be prepared to deliver their mixture to the teacher within 20 minutes. In practice, many students will take longer, particularly if the formula for potassium chlorate is not given and students are not familiar enough with ionic nomenclature.
The teacher will need about one minute per group to announce the group's mixture, ignite it, and wait for student responses. So if there are 15 groups, the teacher should allow about 15 minutes to ignite all the mixtures.
Students combine sodium carbonate and hydrochloric acid generating carbon dioxide gas which is allowed to escape. They measure the actual yield of carbon dioxide produced (missing mass), calculate the theoretical yield using stoichiometry, and then the percent yield. Students understand that 100% yield is the most appropriate answer (based on the Law of Conservation of Mass), so after considering the meaning of significant figures and the uncertainty of their measurements they are asked to decide if they did (or did not) get an answer that might indicate the validity of the Law.
One 50-minute period to perform the lab. One additional period to perform the calculations (optional). Often more able students will have time to begin some calculations at the end of the lab experiment.
Communicating the Value of Chemistry The October 2014 issue of the Journal of Chemical Education is available online to subscribers [http://pubs.acs.org/toc/jceda8/91/10]. The October issue features sustainability; celebrating National Chemistry Week 2014 with articles on food and candy; increasing chemistry understanding for the nonscientist; nanochemistry; investigating materials: plastic & paper; exploring sound; research on chemical equilibrium instruction and student understanding of scale.
Advanced Placement Chemistry Special Issue The September 2014 issue of the Journal of Chemical Education is available online to subscribers [http://pubs.acs.org/toc/jceda8/91/9]. The September issue features a special issue of 20 contributions on Advanced Placement (AP) Chemistry as well as many other articles to help students learn chemistry.
Using Models for Learning Chemistry The August 2014 issue of the Journal of Chemical Education is now available online to subscribers at http://pubs.acs.org/toc/jceda8/91/8. The August issue contains content to spark thinking about models and how to foster meaningful learning in chemistry classrooms and improve student understanding.
The new AP Chemistry curriculum is in the second year of use. Photoelectron spectroscopy (PES) is a topic that generated much discussion because it is an addition to the curriculum. Jamie Benigna of Michigan teaches AP Chemistry, is an AP reader and recently wrote an article about PES for the Journal of Chemistry Education Special Issue. The article discusses the rationale for including PES in the course, explains some background of PES and provides strategies for including PES in your own course. This article is offered as a free preview of the AP Special Issue.