Flame Tests and Testing for Negative Ions

Flame Tests

Sodium ions (Na+) have a yellow/orange flame.

Potassium ions (K+) have a lilac flame.

Calcium ions (Ca2+) have a red flame.

Copper ions (Cu2+) have a blue-green flame.

Method

• Clean a wire loop by dipping it in hydrochloric acid and rinsing with distilled water.
• Dip the clean wire loop into a sample (of a compound or a pure element).
• Put the wire loop in the clear, blue part of the Bunsen flame.
• The flame will be one of the colours above, depending on which element it contains.

Flame tests can be used with both solids and solutions. When using a powdered solid, dip the wire loop into the HCl again to moisten it before dipping it into the solid, so that it…