Simple chemical tests are described that can indicate the presence of certain metals in coins. A wide variety of chemical concepts are involved. The experiments described are a natural fit for the 2019 National Chemistry Week theme of "Marvelous Metals!"
aqueous solution chemistry
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!
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...
Solution to Chemical Mystery #6 is presented. Also, concepts related to the chemical can crush demo are briefly discussed.
Just the other day within my IB Chemistry HL classes, we were discussing the color of transition metal complex ions in solution. It's a bit imperfect, because they are not yet dissolved, but I set up a number of metal chloride salts in order to help students see the pattern. They are arranged according to the position of the metal in the periodic table. It ends up being quite obvious to the students that the only metal salts with color are in the d-block. I'm now in the process of ordering more chloride salts so I can complete the pattern even more the next time I teach this topic.
In this Activity, students investigate a classic chemistry demonstration that uses the phenomenon of freezing-point depression to lift an ice cube out of a glass of water with a thread. They first test how adding salt, pepper, cream, and sugar to cold water affects the temperature.
In this Activity, students investigate the chemistry of the popular Salt Crystal Garden. They grow salt crystals by evaporation from aqueous solutions containing various mixtures of table salt, ammonia, and laundry bluing in order to determine the purpose of each component.