Ever wonder why some call precipitation reactions "double decomposition". Perhaps (or perhaps not) two (double) salts are sort of splitting apart (decomposing?) and then reforming with other radicals. But a solvent (usually water) is necessary to achieve the desired effect. But is adding water to a salt really decomposition?
The solution to "Chemical Mystery #16: A Red, White, and Blue Chemistry Trick for You!" is presented. How this experiment can be used as a springboard to carry out a simple quantitative analysis of salt solubility is also discussed.
Watch this video and see if you can figure out how red, white, and blue colors can all be made from the same chemical solution!
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.
The author shares a series of resources she has created that are built around a post here on ChemEd X about popping a balloon with an orange peel and the concept of polarity.
Are you familiar with the dynamic density bottle experiment? This interesting experiment was invented by Lynn Higgins, and is sold by various science supply companies. Two immiscible liquids (usually salt water and isopropyl alcohol) and two different types of plastic pieces are contained within a dynamic density bottle. The plastic pieces display curious floating and sinking behavior when the bottle is shaken.
Food chemistry is an interesting and fun class for students. Read the article for some suggestions about resources along with an outline of a unit developed around water in cooking.
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...