Chapter 14 Flashcards
What are the physical properties given by the OH group
Volatility
Boiling point
Solubility
How does the OH group affect the boiling point
Alcohols have weak London forces and strong hydrogen bonds
More energy needed to overcome hydrogen bonds
Volatile definition
Alcohols are less volatile than alkanes
Volatile - evaporates easily
How are hydrogen bonds formed
Électronégative oxygen draws electron negativity away from hydrogen to create partial charges
H+ attracts o- on neighbouring molecules
Why are alcohols more soluble than alkanes
They have oh groups that can form hydrogen bonds with water
What is the relationship of adding carbons on the solubility and boiling point
More carbons
Less influence from oh
Bp and solubility become more similar to alkane
What reactions can alcohols participate in
Combustion
Oxidation
Dehydration
Halogénation
Combustion
Alcohol + oxygen = co2 + h2o
What is the oxidising Reagent that primary and secondary alcohols are oxidised by
Acidified potassium dichromate with sulfuric acid
K2cr2o7- h2so4
How does the solution change when oxidised
Cr2 ions are reduced to cr3+ ions
Changes from orange solution to green solution
Oxidation of alcohols into aldehydes
Dilute H2So4
Distillation
Gently heat primary alcohol
With acidified K2Cr2O7
Distil our of mixture as it forms
Alcohols into carboxylic acids
Dilute H2So4
Reflux
Strongly heat alcohol
With excess acidified K2Cr2O7
Reflux reaction mixture
Any intital aldehyde undergoes oxidation as well
Alcohols into ketone
Secondary
Dilute H2So4
Reflux
Heat alcohol under reflux with acidified K2Cr2O7
Halogénation
Alcohols + hydrogen halide = haloalkanes
Reflux
Concentrated H2So4
Mix alcohol with Na halide and concentrated H2So4
And heat under reflux
NaBr + H2So4 —> NaHSo4 + HBr
Alcohol dehydration
Catalyst concentrated H2So4
Reflux
Heat alcohol under reflux in presence of H2So4 catalyst
