solutions

Salt vs. Sugar – A Dissolving Problem

This formative assessment looks at two household chemicals (table salt and sugar) and compares their properties while looking at how they dissolve in water. The “Salt vs. Sugar” formative assessment explores students’ thinking about the question “How does structure influence reactivity?” The main idea that is being targeted is for students to think about what is happening at the molecular level during the solution process. This activity is important for students because it helps create a context for what some of the vocabulary and concepts mean by providing tangible examples of these concepts (such as the concept of saturation).This formative assessment looks at two household chemicals (table salt and sugar) and compares their properties while looking at how they dissolve in water. The “Salt vs. Sugar” formative assessment explores students’ thinking about the question “How does structure influence reactivity?” The main idea that is being targeted is for students to think about what is happening at the molecular level during the solution process. This activity is important for students because it helps create a context for what some of the vocabulary and concepts mean by providing tangible examples of these concepts (such as the concept of saturation).

The Density Bottle Strikes Again

Density Bottles can be used to teach a variety of chemical concepts such as density, solubility, and polarity. In this post it is shown that Density Bottles can also be used to differentiate between heterogeneous and homogeneous mixtures, and to explore light scattering.    

Misconceptions and Struggles with Double Displacement reactions and dissolving...

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.

Puddles, Dissolving and a Cool 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"....