Looking over my student's papers, there may have been more misconceptions created because of the way I planned the curriculum. In all of the experiments students can see and observe that not all of the crystals or material dissolves yet the water starts to conduct. In their minds there is evidence that they believe either something DOES dissolve or it does NOT. Clearly, partial dissolving is initially too much to consider.
Solution to Chemical Mystery #8, and...a challenge!
Addition of a white solid to a green solution causes the solution to separate into some truly beautiful colors...
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"....
At Chem Ed 2015, a teacher from Texas showed me this quick and dirty way to do a distillation that the kids can do. I forgot her name. "Lady from Texas", let me just say "thank you". If you are reading this, please shoot me an email and I will be more than happy to give you credit. It worked really well.
An advantage to teaching on the trimester schedule allows me the opportunity to teach the same course again roughly twelve weeks later. So after grading my 2nd trimester students’ Chemistry B final exams, I was able to evaluate certain topics that caused my students problems, reflect on my teaching, and then determine how I was going to better prepare my students in the 3rd trimester chemistry B class.
Last year I came across a link on Twitter regarding an art installation by Roger Hiorns in England titled “Seizure.” Some of you may have seen it too – a condemned flat in London was essentially sealed off and filled with more than 75,000 L of supersaturated copper sulfate solution.
I’m looking forward to this year’s National Chemistry Week even more than usual. The 2014 theme “The Sweet Side of Chemistry” offers an opportunity to share the chemistry of candy, a super high-interest topic.
In this Activity, students first prepare a standard formulation for a variation on the classic blue bottle reaction using consumer chemicals. They then make appropriate changes to the formulation and observe the results to determine the roles played by each reactant. This Activity could be used with units on chemical kinetics and oxidation-reduction reactions.
In this Activity, students investigate concentration levels by using serial dilution to prepare several solutions of presweetened powdered drink mix. Students taste the solutions to determine at which concentration they first discern the sweetness. A connection is also made to the concentration of pollutants in air.