Qualitative analysis

Qualitative analysis

Finding the unknown. ​

Qualitative analysis

It is an investigative chemistry in which dissolved ions can be identified with the use of specific reagents.

Qualitative analysis

Each ions have specific reaction and from the result, we can identify the ions present in the solution

Identifying cation

Use sodium hydroxide and aqueous ammonia

the hydroxide ion (OH^-) in NaOH and aq. ammonia will bind to the metal cation and will produce a specific color.

The resulting metal hydroxide may also dissolve in excess solutions

Test for Zinc ion

Add sodium hydroxide dropwise then in excess

white precipitate of Zinc hydroxide forms.

white precipitate dissolves in excess sodium hydroxide to form colourless solution.

Multiple Choice

When aqueous ammonia is added to an unknown clear solution, a white precipitate is formed. When excess ammonia is added, the precipitate does not dissolve.

What ion is in the solution?

• Zn2+

• Pb2+

• Ca2+

• Na+

Multiple Choice

When sodium hydroxide is added to an unknown clear solution, a blue precipitate is formed. When access sodium hydroxide is added, the precipitate does not dissolve.

What ion is in the solution?

• Chloride (Cl-)
• Copper (Cu2+)
• Sodium (Na+)
• Iron (Fe2+)