Lesson Plan: Tests for Cations Chemistry
This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to identify aqueous positive ions based on their reactivity and the color and solubility of their salts.
Objectives
Students will be able to
- describe the colors and solubilities of precipitates when is added to various metal cations in aqueous solution (, , , , , , and ),
- describe the colors and solubilities of precipitates when aqueous ammonia is added to various metal cations (, , , , , , and ) in aqueous solution,
- identify which precipitates redissolve when excess or ammonia is added,
- describe the test for the ammonium cation using (no precipitate and pungent ammonia gas is produced),
- identify which metal cations require both the hydroxide and aqueous ammonia test to confirm which metal cation is present,
- write ionic equations for the reaction between metal cations and the hydroxide anion,
- identify an unknown metal ion from the results of the above tests.
Prerequisites
Students should already be familiar with
- ions,
- metals,
- precipitates.
Exclusions
Students will not cover
- flames tests,
- atomic emission spectroscopy,
- tests for anions.
