Qualitative Analysis Flashcards
How can you test for carbonate ions?
Add strong acid to sample
Collect gas produced and bubble through lime water
How can you test for sulphate ions?
Add dilute hydrochloric acid and barium chloride to the sample
What will happen if carbonate ions are present?
Effervescence
Lime water turns cloudy
What happens if sulphate ions are present?
A white precipitate of barium sulphate is produced
What is used to test for halogens?
Acidified silver nitrates (AgNO3)
How can you test for halide ions?
Add aqueous silver nitrate
If colour change is difficult to distinguish add aqueous ammonia, first dilute ammonia then concentrated ammonia
Why do you add nitric acid to test for halides and not HCl?
To remove carbonate ions
Adding HCl would add Cl ions giving a false, positive result