laboratory instruction

Balancing Equations with Molecular Models

molecular model kit

I am a very firm believer that the world of physical science can be visualized and is an excellent medium for teaching students to model and to picture what happens at the molecular level. The first topic we decided to explore was balancing chemical equations. This seems like such a simple topic to chemistry teachers but I have found that it can be quite challenging for many of my inner city students. The first thing they ask me for is a list of rules that they can follow. We can discuss the problems of algorithmic teaching in a later post! For the time being let’s talk about how to get students to understand why they need to balance equations and discuss what we can call “Conservation of Atoms”.

Time required: 

50 minutes

Puddles, Dissolving and a Cool Conductivity Tester...

Conductivity Tester

One of my biggest struggles with students is to try to explain what happens when items, specific inorganic salts, dissolve in water. It might sound simple to me and you. Research shows that students have many real misconceptions when it comes to explaining inorganic salts dissolving in water. My own experience along with other teachers I know is that we are amazed and sometimes frustrated with trying to help students understand the simple process of dissolving, especially with ions. A key piece of equipment is a good conductivity tester. Just got done making a stack of them and can't wait to have students try them. But back to "dissolving"....

JCE 93.07 July 2016 Issue Highlights

Journal of Chemical Education July 2016

Exploration of Instrument Design and Performance

The July 2016 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: cost-effective instrumentation, including 3D printed instruments and low-cost spectroscopy; laboratory instrumentation and equipment; effective teaching assistants in chemistry; laboratory experiments; resources for teaching; puzzles and games to introduce the periodic table.

Especially JCE: July 2016

Back to school time means back to lab time too. Students new to chemistry have a lot on their plates the first few labs—learning unfamiliar safety procedures, becoming accustomed to writing lab reports, even figuring out which glassware they’re looking for in their lab space. How can teachers help them to navigate this newness? Two articles in the July 2016 issue of the Journal of Chemical Education are useful resources for “back to lab” time.

JCE 93.06 June 2016 Issue Highlights

Journal of Chemical Education June 2016

Visualizations for Chemistry Teaching and Learning

The June 2016 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: visualizations for chemistry teaching and learning, periodic table resources for teaching visually impaired students, biochemistry in the classroom and laboratory, spectroscopy in the laboratory, commentaries on analytical chemistry topics, resources for teaching, distilling the archives: guided-inquiry experiments.

PASCO Wireless Temperature Sensor, update on Classkick and with exams coming soon try High School Chemistry: Practice Tests and Flashcards by Varsity Tutors

This past week, as part of our Thermochemistry unit, my students were completing one of my favorite Target Inquiry Labs entitled “ A Very Cool Investigation”.  We were using calorimeters, dissolving ammonium nitrate, and my students were recording the change in temperature using a digital thermometer.  Some of my students had noticed that with si

Olympiad Laboratory Challenge Part II

For my students and me, the AP Chemistry exam does not mark the end of the school year. Once the AP exam is over, my students are exhausted but our class continues to meet for three more weeks. Each year we complete a qualitative analysis lab, but this year we finished earlier than I anticipated. For the first time all year, I have the luxury of time.

Time required: 

45 minutes or less

Argument-Driven Inquiry in Chemistry: Lab Investigations for Grades 9 - 12

argument driven inquiry

I have been on a mission lately to make scientists out of my students. I am long past my fears that they are not capable of discovering the world for themselves or that they won’t learn the content if we spend too much time on science practices. What I have to work on now is orchestrating the experience. The pedagogy underlying Modeling Instruction has become the backbone for much of my instruction lately. This method of instruction not only gives my students an engaging, authentic scientific experience but has resulted in deeper content knowledge.

An Unexpected Source of Inquiry-Based Lab Practicals


Each spring my Local Section of The American Chemical Society (ACS) hosts a rigorous two part exam as part of the selection process for the The International Chemistry Olympiad (IChO)  IChO is an annual international competition for the world’s top chemistry students. Each year, nations from all over the world will send teams of four to compete for top honors.

Time required: 

45 minutes

Stoichiometry Fireworks Lab Quiz

Ignition of sugar and potassium chlorate produces purple flames and sparks.

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.

Time required: 

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.