Alcohols - Organic Chemistry Flashcards
What are alcohols?
Hydrocarbons with a hydroxyl group attached
What are some physical properties of alcohols?
Polar due to O-H group, hydrogen bonding, high boiling and melting points, not reactive, soluble in water
What are the 3 types of alcohols?
Primary, secondary, tertiary
What are primary alcohols?
Alcohols where the carbon with the alcohol group is directly attached to one other carbon
What are secondary alcohols?
Alcohols where the carbon with the alcohol group is directly attached to two other carbons
What are tertiary alcohols?
Alcohols where the carbon with the alcohol group is directly attached to three other carbon
What reactions do alcohols go through?
Combustion, oxidation, dehydration and substitution
What is oxidation in alcohols?
Addition of an oxygen molecule or loss of electrons but only with primary and secondary alcohols
What products do oxidation of primary alcohols form?
Aldehydes and carboxylic acids
What conditions are needed to from aldehydes from oxidation of primary alcohols?
Gentle heating and acidified potassium dichromate
What conditions are needed to from carboxylic acids from oxidation of primary alcohols?
Reflux and excess acidified potassium dichromate to make sure of the alcohol reacts to become a carboxylic acid
What products do oxidation of secondary alcohols form?
Ketones
What conditions are needed to from ketones from oxidation of primary alcohols?
Reflux and acidified potassium dichromate
What colour do alcohols turn when they are oxidised?
Orange to green due to the green dichromate ions
Why can’t tertiary alcohols be oxidised?
Because there is no hydrogen from the carbon directly attached to the alcohol group for the oxidising agent to remove
