Topic 6 Halogenoalkanes and Alcohols Flashcards
What is the reagent and conditions to produce an alkene from a halogenoalkane.
Warm ethanolic NaOH carried out under reflux.
What is the reagent and reason to use this reagent with halogenoalkanes to make triple bond N
Warm ethanolic potassium cyanide
Increases number of carbon atoms in the chain.
Why are things heated in a sealed container?
Heating increases rate of reaction and no sealed tube would lose gas.
Which bond takes longest to form precipitate?
Chloro
Why would you add ethanol in a silver nitrate test for halogenoalkanes?
Dissolves the halogenoalkane
Why are halide ions present in mixture when silver nitrate is done?
Halogenoalkane hydrolysed by water
C-Hal bond breaks therefore ions present.
An experiment that enable hydrolysis rates of halogenoalkanes to be compared
Ethanol as solvent
Use silver nitrate
Equal amounts halogenoalkane
Measure time taken
Water bath control raised temp
Jodo fastest - lowest bond enthalpy
What are stereoisomers?
Compounds that have the same structural formula but atoms have different arrangement in 3D space.
Z
Same side
E
Opposite
Chemical test positive result for alcohol but not carboxylic acid.
Bromine water goes colourless
What colour precipitate for iodine?
Yellow
Conditions to form alcohol from halogenoalkane
Warm aq NaOH
What conditions when reacting with ammonia - halogenoalkane.
Excess ethanolic ammonia
What else is made when you react halogenoalkane with ammonia
Amine (fishy smell)
What type of alcohol reacts fastest with HCl.
Tertiary
What reactants can you use to make a chloroalkane from an alcohol
HCl
PCl5
Conditions for making Bromoalkane from alcohol
NaBr
50% acid catalyst
H2SO4
Reagent for making iodoalkane from alcohol
Phosphorus triiodide
What happens during dehydration of an alcohol?
Water eliminated
Acid catalyst used H2SO4 or H3PO4
Forms alkene plus water
What reagent can alcohols be oxidised by
Potassium dichromate
Testing for aldehydes and ketones
Fehlings solution
Blue -> brick red for aldehydes because it is an oxidising agent
What does potassium dichromate change colours from and to?
Orange to green (Cr3+)
