General

A Chemist Celebrates the International Year of Light

Happy New Year!  Did you know that 2015 is the International Year of Light (IYL)? IYL is a “global initiative adopted by the United Nations to raise awareness of how optical technologies promote sustainable development and provide solutions to worldwide challenges in energy, education, agriculture, communications and health1”.  IYL is sponsored by several organizations with interests in science and science education, including the European Physical Society, the Institute of Physics, the American Physical Society, and the American Institute of Physics.  You can find several lesson plans, videos and other educational resources on the IYL website2

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. 

Stoichiometry Fireworks Lab Quiz

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.

Mass of a Reaction Product

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.

Chemistry At the Mall

My local chapter of the American Chemical Society sponsors an annual event at a local mall called “Chemistry at the Mall”. The event is in celebration of National Chemistry Week. This year’s theme is “The Sweet Side of Chemistry – Candy”. I advise an ACS ChemClub and we hosted a table at “Chemistry at the Mall”. Ten student members worked shifts from 11am – 4pm. This was a great way to get involved with my local chapter and meet some other members. My students had a great time providing outreach and introducing young children to chemistry.

Melting Pennies

I am fascinated by the chemistry of pennies. I have tried several experiments found in the Journal of Chemical Education.