chemecal analasis

just a few notes on chemical analysis

Testing for Cations

Cations are positively charged (+) ions. There are 2 basic tests for them:

• Flame test
• Adding NaOH (aq) to solution of ionic compound

The flame test involves a clean nichrome wire first being dipped into a solution of Hydrochloric acid. This is then dipped into the solid powdered compound of the metal being tested. This is then held over a Bunsen Burner and the flame colour is observed.

The following results are gained for each ion:

• Na⁺ - Yellow flame
• K⁺ - Lilac (light purple) flame
• Ca²⁺ - Red flame
• Cu²⁺ - Blue / green flame

The second test of adding NaOH (sodium hydroxide) gives a coloured…