All in the Family - Periodic Trends Demonstration Kit
By: The Flinn Staff
Item #: AP7281
The All in the Family Periodic Trends Demonstration Kit provokes exploration of similarities and differences In the reactivity of halogens. Students rank halogens from most to least active and find the periodic trend in their reactivity.
In every family there are similarities and differences. The same is true in chemical families as well! Explore similarities and differences in the reactivity of the halogens and promote critical thinking with this inquiry-based demonstration. Dilute aqueous solutions of chlorine, bromine, and iodine are prepared fresh and mixed pair-wise with chloride, bromide or iodide ions in a two-phase solvent system. Will chlorine oxidize bromide ions? Will bromine oxidize iodide ions? Will iodine oxidize chloride or bromide ions? Why or why not? Rank the halogens from most active to least active and discover the periodic trend in their reactivity based on observed color changes across the liquid layers. Reactions are carried out in capped glass bottles supplied with the kit. Small-scale yet effective demonstration has been optimized to minimize halogen concentrations and increase safety. Work with halogen solutions in a hood or well-ventilated lab only. Teacher Demonstration Notes and student worksheet included. Enough materials are included to perform the demonstration seven times.
Concepts: Halogens, periodic table, groups or families, single replacement reactions.
Time Required: 20 minutes
Materials Provided: Hexane, hydrochloric acid, iodine, sodium bromide, sodium chloride, sodium hypochlorite and sodium iodide solutions, square glass bottles, and caps.
Notes: Halogen solutions should be worked with in a fume hood or well-ventilated lab.