general shit Flashcards
(42 cards)
What type of addition can alkenes undergo
electrophilic addition
what is an electrophile
electrophiles are electron pair acceptors which are attracted to areas of high electron density
why are electrophiles attractred to carbon double bonds
the carbon double bonds have high electron density
what happens to the carbon double bonds ion electrophilic addition
the double bond opens up and atoms get added to the carbon atoms
what reaction with alkenes produces an alkane
hydrogenation
what are conditions for hydrogenation
alkenes will react with hydrogen and a nickel catalyst at 150 degrees
what forms when halogens react with alkenes
dihaloalkanes
what reaction with alkenes produces alcohols
steam hydration
conditions for steam hydration
hydrated by steam at 300 degrees
pressure of 60-70 atm
phosphoric acid catalyst
reversible reactions cause low yeld unlessyou recycle
why are alcohols polar
the hydroxyl group is electronegative which pulls electron density away from the carbon atom
why are alcohols siluble in water
the partially positive hydrogen in the OH bond can form hydrogen bonds with oxygens from neighbouring molecules. hydrogen bonds are formed between the oxygens in water which lets alcohols mix freely
what happens to the solubility of alcohols as they increase in size
solubility decreases as most of the molecule is non-polar. causing less attraction for the for the H2O molecules
what reactions do alcohols have to form haloalkanes
alcohols can react with compounds containing halide ions in a substitution reaction causing the OH group to be replaces with a halogen forming a haloalkane
how do alcohols become alkenes
alcohols become alkenes through dehydration reactions
what is a dehydration reaction
eliminating water from alcohols in an elimination reaction
how does a dehydration reaction happen
the alcohol is mixed with an acid catalyst (sulfuric or phosphoric, both concentrated) then heated
where does the water come from in dehydration reactions
the water molecule is made up from the hydrixyl group and a hydrogen atom that was bonded to a carbon atom adjacent to the hydroxyl carbon
what does burning alcohol in a plentiful supply of oxygen cause
its causes combustion of the alcohol
what are products of combustion
CO2 and H2O
what are primary alcohols oxidied to?
primary alcohols are oxidised to aldehydes adn then to carboxylic acids
what are secondary alcohols oxidised to?
secondary alcohols are oxidised to ketones only
what are tertiaty alcohols oxidised to
they dont oxidise
how are aldehydes formed from primary alcohols
aldehydes are formed by gently heating excess alcohol with a controlled amount of oxidising agent in a distilling apparatus
how are carboxylic acids formed from primary alcohols
the alcohol is mixed with excess oxidising agent and heated under reflux