alcohols reactions Flashcards
chlorination of alcohols
substitution
PCl5 or conc HCL
room temperature
alcohol + PCl5 —> chloroalkane + POCl3 + HCL
combustion of alcohols
combustion
oxygen
alcohol + O2 —> H2O + CO2
reaction of alcohols to alkenes
elimination
conc H2SO4 or H3PO4
heat
alcohol —-> alkene + H2O
bromination of alcohols
substitution
KBr + conc H2SO4
heat under reflux
alcohol + HBr —> bromoalkane + H2O
iodination of alcohols
substitution
P and I2
heat
alcohol + PI3 —> iodoalkane + H3PO3
oxidation of alcohol to aldehyde
oxidation
K2Cr2O7 + H2SO4
distil immediately
1° alcohol + [O] —> aldehyde
oxidation of alcohol to carboxylic acid
oxidation
K2Cr2O7 + H2SO4
heat under reflux
1° alcohol —> aldehyde —> carboxylic acid
test for the OH group
add PCl5 to alcohol - produces steamy fumes
collect fumes and bubble through AgNO solution - produces a white ppt
what are 2° alcohols oxidised to
keytones
which alcohols are oxidised with K2Cr2O7 and H2SO4
1° and 2°
not 3°
colour change when 1° and 2° alcohols are oxidised
orange solution —> green solution
oxidation of 2° alcohol to keytone
k2cr2o7
dilute h2so4
heat under reflux
oxidation of ethanol to ethanal conditions explanation
primary alcohols are oxidised in 2 steps
alcohol -> aldehyde -> COOH
conditions stop oxidation at aldehyde
method
oxidation of ethanol to ethanal
- 5cm3 distilled water pear shaped flask
- 2cm3 conc H2SO4 dropwise to water
- swirl and cool in ice bath after each add
- add anti bumping granules to flask
- 5g sodium dichromate in small beaker
- dissolve in 5cm3 distilled water
- 4cm3 ethanol
- put mixture into dropping funnel
- set up apparatus
- cold water through condenser
- surround receiver vessel with ice water
- heat H2SO4 until boiling
- add ethanol/dichromate mixture in pear shaped flask
- warm mixture gently
