8.3 Qualitative Analysis Flashcards
How do you test for carbonate ions?
Add dilute nitric acid to a test tube containing the compound
What is the observation if carbonate ions are present?
Carbon dioxide forms, bubbles of gas
How do you test for sulfate ions?
Add barium nitrate
What is the observation if sulfate ions are present?
A white precipitate if barium sulfate forms
How do you test for halide ions?
Add silver nitrate
What precipitate do chloride ions form?
A white precipitate
What precipitate do bromide ions form?
A cream precipitate
What precipitate do iodide ions form?
A yellow precipitate
In what order should you carry out the the qualitative tests?
- Carbonate
- Sulfate
- Halide
How do you test for nitrate ions?
Add aqueous sodium hydroxide and heat gently, test the gas releases with moist pH paper
What is the observation if nitrate ions are present?
pH paper turns blue
Why does ammonia gas not bubble?
It is very soluble, so the mixture needs to be warmed in a water bath to release the ammonia gas
