carbonyls

Question 1

outline the conditions, products and observations for the oxidation of aldehydes.

Answer 1

acidified dichromate (VI) ions and dilute sulphuric acid heated under reflux. Forms a carboxylic acid (-COOH). orange to green.

Question 2

why do ketones not undergo oxidation reactions.

Answer 2

they have low reactivity. this is good for being able to distinguish between ketones and aldehydes when reacting with tollens reagent.

Question 3

carbonyls can undergo n___ a___ reactions. why is this.

Answer 3

nucleophilic addition.
C=O nature of the polar bond.
they attract nucleophiles towards the slightly positive carbon.

Question 4

what is the reducing agent that is able to reduce carbonyls to ___. what are the conditions of this reaction.

Answer 4

NaBH4
alcohols -OH.
Water, 2[H] (reducing agent) and heat.
aldehydes make primary alcohols whilst ketones make secondary alcohols.

Question 5

what is hydrogen cyanide. how is it made safely. why is it useful.

Answer 5

colourless, poisoneess liquid.
NaCN + sulphuric acid are used to provide HCN into the reaction.
it increases the carbon chain length.
the produce contains 2 functional groups and is classed as a hydroxynitriles.

Question 6

how is an acid anhydride formed from a carboxylic acid.

Answer 6

the removal of water from 2 carboxylic acids.

Question 7

how can carboxylic acids form esters.

Answer 7

an alcohol is warmed with a carboxylic acid to form an ester with a small amount of sulfuric acid.