problem solving

NGSS Update #2

Happy December ChemEdX community! On December 2, 2014 I attended the second of three workshops on NGSS (Next Generation Science Standards) through our local ISD (in Kalamazoo County it is known as KRESA).

Conceptual Chemistry

In a recent contribution to ChemEd X "Stoichiometry is Easy", the author states that he has "vacillated over the years between using an algorithmic method, and an inquiry-based approach to teaching stoichiometry. " I would like to suggest that there is another approach to mastering stoichiometry and that it should precede the algorithmic one: it is the conceptual approach based on a particle model to represent the species involved in chemical reactions.

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. 

Finding and Writing the Molar Mass of Elements

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. It is designed to help develop good habits in representing molar mass and other conversion factors, and to emphasize the idea that a conversion factor has a numerator and denominator that "name" identical quantities using different measures.

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.

AACT: A Community for K–12 Teachers of Chemistry

On September 2, the American Association of Chemistry Teachers (AACT) launched its official website, loaded with lots of resources and member benefits. If you visit, you will find many great tools that K–12 teachers of chemistry can use in their classrooms; the new online periodical, Chemistry Solutions; professional development opportunities; and a community for you, in addition to many other benefits.