5257253
Chemistry IGCSE
- Li - Crimson Red flame
- Na - Yellow-Orange
flame
- K - Lilac
Flame
- Ca - Brick-Red
flame
- Dip clear platinum loop
in HCL (aq)
- Hold in a roaring blue
flame
- Wait till it burns with no
colour
- Dip in sample then
place in flame
- Test for coloured precipitate with Sodium
Hydroxide (NaOH)
- Copper 2+ Ions - Blue precipitate
- Cu 2+ (aq) + 2OH- (aq) → Cu(OH)2 (s)
- Cu 2+ (aq) + 2OH- (aq) → Cu(OH)2 (s)
- Iron 3+ ions - Reddish-Brown precipitate
- Fe 3+ (aq) + 3OH- (aq) → Fe(OH)3 (s)
- Fe 3+ (aq) + 3OH- (aq) → Fe(OH)3 (s)
- Iron 2+ ions - Sludgy green precipitate
- Fe 2+ (aq) + 2OH- (aq) → Fe(OH)3 (s)
- Fe 2+ (aq) + 2OH- (aq) → Fe(OH)3 (s)
- Copper 2+ Ions - Blue precipitate
- Ammonium Compound + NaOH = Ammonia!
- Usually smells of cat urine
- Check using litmus paper
- Damp red litmus paper blue
- NH4 give off ions which react with the litmus
paper making it blue as it is an alkaline
- NH4 give off ions which react with the litmus
paper making it blue as it is an alkaline
- Damp red litmus paper blue
- Check using litmus paper
- Usually smells of cat urine
- Test for Anions
- Test for Carbonates
- Add dilute Hydrochloric acid (aq) to the test sample
- If carbonates are present then carbon dioxide will be released
- Carbon dioxide turns limewater cloudy (Test)
- CO3 (s) + 2H (aq) → CO2 (g) + H2O (l)
- CO3 (s) + 2H (aq) → CO2 (g) + H2O (l)
- Carbon dioxide turns limewater cloudy (Test)
- If carbonates are present then carbon dioxide will be released
- Add dilute Hydrochloric acid (aq) to the test sample
- Test for Sulfates
- Add dilute Hydrocholoric acid (aq) then barium chloride solution
- A white precipitate means the compound was origanally a sulfate
- Ba (aq) + SO (aq) → BaSO4 (S)
- Ba (aq) + SO (aq) → BaSO4 (S)
- A white precipitate means the compound was origanally a sulfate
- Add dilute Hydrocholoric acid (aq) then barium chloride solution
- Test for Halides
- To test for chloride, bromide or iodide ions, add dilute
nitric acid (aq) then add silver nitrate solution (AgNO3)
- Chloride Ion gives a White Precipitate of Silver Chloride
- Bromide ion gives a Cream precipitate of Silver Bromide
- Iodide ion gives a Yellow Precipitate of Silver Iodide
- Ag (aq) + I (aq) → AgI (S)
- Ag (aq) + I (aq) → AgI (S)
- Ag (aq) + Br (aq) → AgBr (S)
- Iodide ion gives a Yellow Precipitate of Silver Iodide
- Ag (aq) + Cl (aq) → AgCl (S)
- Bromide ion gives a Cream precipitate of Silver Bromide
- Chloride Ion gives a White Precipitate of Silver Chloride
- To test for chloride, bromide or iodide ions, add dilute
nitric acid (aq) then add silver nitrate solution (AgNO3)
- Test for Carbonates
Media attachments
Want to create your own Mind Maps for free with GoConqr? Learn more.