Chemistry for Everyone
W
A Disciplined Chemical Puzzle Miguel Peris Department of Chemistry, Polytechnic University of Valencia, 46071 Valencia, Spain;
[email protected] Supplemental Material
Over the past few years, several puzzles have been published in this Journal; some of the most interesting examples are cited below (1–4). They clearly illustrate a format that attracts students’ interest and adds extra motivation to the process of learning chemistry. This puzzle was developed as a resource for teaching intermediate chemistry students. After addressing the chemistry content (relying on some inorganic and organic chemistry knowledge and independent or small-group research), students use general intelligence and logic skills to solve this chemistry puzzle.
W
Disciplined Chemistry
Solving the Puzzle
Six friends of different ages (none of them retired) and with expertise in six different areas of chemistry are sitting around a hexagonal table. Each has a badge showing the name of a chemical compound whose molecular mass equals her age. Identify the name, age, subdiscipline of chemistry, and position around the table of each person by using these data:
Using the figure and columns below, fill in the missing information with answers you have determined from the data provided.
The Disciplined Chemistry puzzle and its answers are available in this issue of JCE Online. Literature Cited 1. 2. 3. 4.
Bertolini, T.; Tran, P. J. Chem. Educ. 2006, 83, 590–591. Swain, D. J. Chem. Educ. 2006, 83, 589. Bertolini, T. J. Chem. Educ. 2002, 79, 828. Spencer, H.; Kusdra, L. J. Chem. Educ. 1998, 75, 487.
Who is seated where at this table of chemistry experts?
1. The expert in Inorganic Chemistry knows that the compound of Gemma’s neighbor has the same molecular mass as another substance that undergoes a Cannizzaro reaction in alkaline medium and yields a colored precipitate with 2,4dinitrophenylhydrazine.
1 6
2
5
3
2. Ann’s neighbor has a compound with 85.71% carbon and 14.29% hydrogen, and no possibility of cis–trans isomerism. 3. The compound of the person opposite of Gemma does not precipitate with aqueous solutions of alkaline-earth metal ions.
4
4. The age of the person on Sonia’s right equals that of Sylvia less the number of electrons accepted by the dichromate ion when it reacts with an iron(II) salt in an acid medium. 5. The youngest, who is not a neighbor of the Biochemistry expert, has a hydrocarbon, a portion of which—after combustion—produces 17.6 g carbon dioxide and 10.8 g water. 6. The expert in Analytical Chemistry has an acid; the complete neutralization of 0.2368 g of this acid requires 8.0 mL of 0.4 M barium hydroxide solution.
Table Position
Chemists’ Names a
1
Sylvia
7. The specialists in Physical Chemistry and Agrochemistry are facing each other.
3 4
9. Connie, who is sitting between Sonia and Esther, is by far the oldest of all.
5
10. The specialist in Agrochemistry has a liquid compound that produces yellow stains on the skin and, when hot and concentrated, reacts with a piece of copper giving rise to an orange vapor.
6
•
Chemists’ Subdisciplines b
2
8. Esther, whose compound has an unpleasant odor, is sitting opposite of the expert in Organic Chemistry; she is as many years younger than the specialist in Physical Chemistry as the number of bonding pairs in the molecule of periodic acid.
www.JCE.DivCHED.org
Chemists’ Ages
aThe
names are Gemma, Ann, Sonia, Sylvia, Esther, and Connie. subdisciplines are Inorganic Chemistry, Biochemistry, Analytical Chemistry, Physical Chemistry, Agrochemistry, and Organic Chemistry. bThe
Vol. 84 No. 4 April 2007
•
Journal of Chemical Education
609
