![]() This was really a lot of fun! Throughout our combined efforts, we discovered some really cool things. Grazyna and I began communicating on Twitter about these experiments, and one afternoon we even spent an hour or two “together”, electronically messaging back and forth about various experiments we were trying. Left to right: Test tubes containing yellow food dye in water and blue food dye in 70% isopropyl alcohol Mixing the yellow and blue fluids to form a green solution Addition of potassium carbonate to form a green solution separation into blue and yellow layers upon dissolution of potassium carbonate. The blue dye, which dissolves better in acetone, ended up in the acetone layer.įigure 3: Experiment carried out by one of Grazyna Zreda's students. ![]() The yellow dye, which dissolves better in water than in acetone, ended up in the salt water layer. As a result, the ion-dipole forces pulled water molecules away from acetone molecules and the liquids separated into the two separate phases. These ion-dipole interactions attracted water molecules much more strongly than the acetone-water hydrogen bonds. When the salt dissolved into the mixture, the resulting Na + and Cl - ions interacted very strongly with water molecules through ion-dipole forces (Figure 2). When a lot of table salt was added, the green solution separated into two layers: a blue colored, acetone rich layer on top and a yellow-colored, salt-water rich layer on bottom. Image made using Odyssey modeling software.Īll four of these components mixed very well together (acetone, water, blue dye, yellow dye) to form a green colored solution results. The other yellow dye dissolves very well in water, but not so well in acetone.Īcetone and water dissolve well in one another due to hydrogen bonding interactions between the oxygen atom on acetone molecules and the O-H bond on water molecules (Figure 1).įigure 1: Representation of a hydrogen bond (yellow dashed line) formed between a molecule of acetone (lower molecule) and a molecule of water (upper molecule). ![]() The dye on blue glitter dissolves very well in acetone, but not so well in water. The yellow dye was obtained from yellow food dye, while the blue dye was obtained from blue glitter. I first mixed acetone, water, and two different dyes without adding any salt. In Mystery #8 I used acetone as the water soluble organic liquid and table salt as the ionic substance. ![]() 1 You can see how this works (and also the solution to Mystery #8) in the video below: If enough salt is added, the mixture separates into two layers: one rich in water, and the other rich in the organic liquid. In the “salting out” experiment, a water-soluble ionic salt is added to a mixture of water and a water-soluble organic liquid. While neither Grazyna nor Alfredo figured out exactly how I pulled off this trick, they both determined that I was making use of the “salting out” phenomenon. If you wish to know more about this challenge, please be sure to read the Challenge section found at the end of this blog post.Ĭongratulations to Grazyna Zreda and Alfredo Tifi who both solved Chemical Mystery #8. Preface: I am proposing a challenge based on this mystery.
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