All Ion Tests Flashcards
What’s the test for functional group sulfate (SO4)
- Acidify with dilute HCl
- Add BaCl2
- White precipitate
What’s the test for functional group carbonate (CO3)
- Add dilute HCl
- Effervescence
- Gas produced turns Limewater cloudy
What’s the test for OH-
- Damp red litmus paper
- Turns from red to blue
What’s the test for the 3 halide ions Cl-, Br-, I-
- Acidify with dilute HNO3
- Add AgNO3
- (Additional test) Add dilute NH3, then conc NH3
What’s the test for NH4+
- Add NaOH
- Heat
- Damp red litmus paper turns from red to blue
What’s the test for Mg2+
In separate test tubes:
- add dilute NaOH —> white ppt
- add dilute H2SO4 —> no visible change
What’s the test for Ca2+
In separate test tubes:
- add dilute NaOH —> white ppt
- add dilute H2SO4 —> slight white ppt
What’s the test for Sr2+
In separate test tubes:
- add dilute NaOH —> no visible change
- add dilute H2SO4 —> white ppt
Whats the test for Ba2+
In separate test tubes:
- add dilute NaOH —> no visible change
- add dilute H2SO4 —> white ppt
What’s the test for 1°, 2°, 3° alcohols
1° & 2°: add acidified potassium dichromate K2Cr2O7 -> orange to green
3° - dichromate remains orange
What’s the general test for all alcohols
add metallic Na -> effervescence (H2 gas made)
What’s the fehlings test for aldehydes
- warm with fehlings solution
- from blue to red ppt
What’s the Tollens test for aldehydes
- warm with tollens reagent
- silver mirror
What’s the test for alkenes
- shake with bromine water
- goes from orange to colourless
What’s the test for carboxylic acids
Add a carbonate eg Na2CO3
- effervescence
- CO2 released which will turn limewater cloudy
