Alcohols Flashcards
How are chloroalkanes produced
react alcohols with PCl5 or HCl
Equation for alcohol reacting with PCl5
ROH + PCl5 –> RCL + HCl + POCl3
equation for alcohol reacting with HCl
ROH + HCl –> RCl + H2O
what structure of alcohol reacts fastest with HCl
Tertiary structure
What structure of alcohol reacts slowest with HCl
Primary
In what type of reaction do bromide ions and alcohols react
substitution reaction
How do you make iodoalkanes from an alcohol
reacting it with PI3
equation for alcohol reacting with PI3
3ROH + PI3 –> 3RI + H3PO3
How do you form an alkene from an alcohol
eliminate water by dehydrating it
what type of reaction forms an alkene from an alcohol
elimination reaction
how is and alkene formed from an alcohol
mix the alcohol with an acid catalyst eg H3PO4 and heat it
What is the general formula for an alcohol
CnH2n+1OH
how do you make a bromoalkane from from an alcohol
react with a compound containing a bromide ion eg NaBr, and add an acid catalyst eg 50% concentrated H2SO4
What is the simplest way to oxidise an alcohol
burn it
What is a combustion reaction
when C-C and C-H bonds break and the alcohol is completely oxidised to make CO2 and water
What do primary alcohols oxidise to
aldehydes and carboxylic acid
What do secondary alcohols oxidise to
ketones only
what do tertiary alcohols oxidise to
they won’t be oxidised
name an oxidising agent used to mildly oxidise alcohols
acidified dichromate Cr2O7
What colour change occurs when the dichromate ion is reduced to a chromium ion
orange to green
what is the difference between an aldehyde and a ketone
aldehydes have a hydrogen and one alkyl group / ketones have two alkyl groups
How do you test is a compound is aldehyde or ketone
benedicts solution or fehlings solution. aldehyde makes brick red precipitate and ketone has no change as it can’t be oxidised easily
What happens if you oxidise a primary alcohol twice
first form an aldehyde which is the oxidised to form a carboxylic acid
how do you form an aldehyde and a carboxylic acid
aldehyde is distilled so gently heated / carboxylic is refluxed so vigorously heated
