Qualitative analysis Flashcards
How can you test for carbonate ions
Add strong acid to the sample
Collect the gas and pass it through lime water
What observations are seen for a positive test for carbonate ions
Fizzing
Limewater turns cloudy
How can you test for sulphate ions
Add dilute hydrochloric acid and barium chloride to the sample
What are the observations for a positive sulphate test
White precipitate of barium sulphate is produced
What do you use to test for halide ions
Dilute nitric acid and silver nitrate
Why do you add nitric acid to test for halides
To remove the carbonate ions
Write the result and equation for chloride ions
White precipitate forms
Ag+ + Cl- —> AgCl
Write the result and equation for bromide ions
Cream precipitate forms
Ag+ + Br- —> AgBr
Write the result and equation for iodide ions
Yellow precipitate forms
Ag+ + I- —> AgI
How can you test for ammonium ions
Add sodium hydroxide to sample and warm it
Test the gas produced with red litmus paper
What are the observations for positive ammonium ions test
Red litmus paper turns blue
Ammonia has a strong smell
