high school chemistry

Chemical Mystery #9: Liquid Nitrogen vs. Dry Ice

Bucket launch

A 2L soda pop bottle is filled about one-third full with either liquid nitrogen or solid carbon dioxide (dry ice) and water. The bottle is sealed and a plastic bucket is placed on top. Do you think the liquid nitrogen or dry ice and water will make the bucket go higher? Can you explain the results using chemistry?

Especially JCE: January 2017

Jan 2017 issue of JCE

Highlights from the January 2017 issue of the Journal of Chemical Education of special interest to high school chemistry teachers.

JCE 94.01 January 2017 Issue Highlights

Journal of Chemical Education January 2017

Ringing in Volume 94

The January 2017 issue of the Journal of Chemical Education is now available online to subscribers. Topics featured in this issue include: NMR spectroscopy; examining assessment; inquiry-based practices; cost-effective instrumentation; miscibility demonstrations; innovative laboratory experiments; from the archives: lightsticks.

Curriculum Maps and Standards

Curriculum map and Standards word cloud

This is a program that has an electronic copy of the map for all teachers to see. The entire map is tied to standards that are a version of state, federal and or local standards. Any formative assessment can easily be graded and tied to a standard. The data can be used to break down how the kids are doing in any one standard and plan future lessons accordingly. If we need to change to meet the needs of our students, we can and should immediately. It is not perfect but is trying to maximize data collection and analysis to help teachers and students.

Modeling and Street Tacos

Modeling attempt

Show the kids an event. Have them develop a model. Have each kid draw and write about the model and force them to ask themselves if this model can explain the event. As a teacher, first say something nice about it and then look for their misconceptions and use this as a formative assessment. Combine the individual models with others. Slowly build a larger model and constantly ask if this really explains the event.

Reflections from Kinetics - Solidifying Why I Teach Method of Initial Rates AND Integrated Rate Laws

kinetics demonstration

I taught my students how to use the method of initial rates. I taught my students rate laws. However, they strugged to differentiate when to use what method. Upon further probing, they struggled to articulate why one might use one method over the other. They could parrot back some ideas ("The rate law tells you about the particles involved in the rate determining step of the reaction."), but I wasn't convinced of mastery and connections.

Isotopes, Nuts, Bolts and Eggs

plastic egg atom models

This is the first isotope activity I have tried where the students can look inside the model that resembled the atom and find information that reinforced what an isotope actually is. Furthermore, the quantitative data forced them to examine beliefs about different types of averages and what the numbers really mean.

Dry ice in five different liquids

Dry ice in five different liquids

You probably know what happens when you place dry ice in water. Do you know what happens when dry ice is placed in acetone or glycerin? Read this and find out!

Gizmos Part II: Chemical Reactions

Gizmos Logo

Last month, I shared about a new PD opportunity I had the privilege of participating in called Gizmos. You can read about it here. After Thanksgiving break, my Chemistry 1 and Honors Chemistry 1 classes began our Chemical Reactions unit.

Silver Plated Ornaments

silver ornaments

I have used several different versions of the Silver Mirror or Tollen's Test lab. I am sharing the method that has proven to be the most reliable for me. The solutions should be made fresh, the directions must be followed closely and timing is very important. I like the fact that relatively small amounts of the chemicals are required, but as always you must be vigilant with safety precautions. 

Time required: 

15 minutes of prep time and 20 minutes of class time if you have multiple hoods available for students to use. I only have one hood, so I have another activity for students to complete while two groups rotate through the lab over two 60 minute class periods.