Test Tube Tests Flashcards
Which type of molecules react with bromine water?
Alkenes
Which type of molecules react with acidified potassium dichromate?
1° alcohols
2° alcohols
Aldehydes
Which type of molecules react with Tollen’s reagent?
Aldehydes
Which type of molecules react with Fehling’s solution?
Aldehydes
Which type of molecules react with sodium carbonate?
Carboxylic acids
What is the reagent used to test for alkenes?
Bromine water
What reagent is used to test for primary and secondary alcohols?
Acidified potassium dichromate
Which reagents are used to test for aldehydes?
Acidified potassium dichromate
Tollen’s reagent
Fehling’s solution
Which reagent is used to test for carboxylic acids?
Sodium carbonate
What observation is made when bromine water reacts with an alkene?
Orange to colourless
What observation is made when acidified potassium dichromate reacts with a 1° alcohol?
Orange to green
What observation is made when acidified potassium dichromate reacts with a 2° alcohol?
Orange to green
What observation is made when acidified potassium dichromate reacts with an aldehyde?
Orange to green
What observation is made when acidified potassium dichromate reacts with a ketone?
No visible change / solution stays orange
What observation is made when Tollen’s reagent is reacted with an aldehyde?
Silver mirror formed
What observation is made when Tollen’s reagent is reacted with a ketone?
No visible change
What observation is made when Fehling’s solution is reacted with an aldehyde?
Brick red precipitate formed
What observation is made when Fehling’s solution is reacted with a ketone?
No visible change
What observation is made when sodium carbonate reacts with a carboxylic acid?
Effervescence
Why does bromine water go from orange to colourless when reacting with alkenes?
Electrophilic addition of Br2 to Alkene
Why does acidified potassium dichromate go from an orange to green solution when adding a 1° alcohol / 2° alcohol / aldehyde?
(Cr2O7)2- (orange) reduced to Cr3+ (green) when alcohol / aldehyde oxidised
Why does Tollen’s reagent form silver mirror when you react it with aldehyde?
Ag+ in Tollen’s reagent reduced to Ag(s) when aldehyde oxidised
Why is there no visible change when you react acidified potassium dichromate with ketones?
Ketones cannot be further oxidised
Why is there no visible change when you react Tollen’s reagent with ketones?
Ketones cannot be further oxidised
Why does Fehling’s solution form brick red precipitate when reacted with aldehyde?
Fehling’s solution reduced when aldehyde is oxidised
Why is there no visible change when you react Fehling’s solution with ketones?
Ketones cannot be further oxidised
Why is effervescence formed when you react sodium carbonate with carboxylic acids?
Formation of CO2
What reagent is used to test for Ba2+ ions?
H2SO4
What reagent is used to test for SO4^2-?
BaCl2
What reagent is used to test for Mg^2+ ions?
NaOH
What reagent is used to test for OH- ions?
MgCl2
What reagent is used to test for Cl-?
AgNO3
What reagent is used to test for Br- ions?
AgNO3
What reagent is used to test for I- ions?
AgNO3
What reagent is used to test for AgCl?
Dilute NH3
What reagent is used to test for AgBr?
Concentrated NH3
What reagent is used to test for NH4^+?
NaOH & Heat
What reagent is used to test for CO3^2-?
Any acid (HNO3 is best)
What observation is made when reacting Ba2+ ions with H2SO4?
White precipitate
What observation is made when reacting SO4^2- ions with BaCl2?
White precipitate
