Chapter 26 Carbonyls and Carboxylic acids Flashcards
What is the carbonyl functional group and what are the most common organic compounds that contain it?
C==O
Aldehydes and ketones
Describe the oxidation of aldehydes and ketones
Aldehydes can be oxidised into alcohols with an oxidising agent of K2Cr2O7/H2SO4
Ketones cannot be oxidised due to a lack of reactivity
Explain nucleophilic addition reactions of the carbonyl group
The carbonyl group is polar because oxygen is more electronegative than carbon and due to this polarity a nucleophile can be attracted and will attack the slightly positive carbon atom resulting in addition across the C==O double bond
What reducing agent is used to reduce aldehydes and ketones into alcohols?
Sodim tetrahydridoborate(III) NaBH4
What is the difference in products in reducing aldehydes and ketones into alcohols?
Aldehydes reduce into primary alcohols
Ketones reduce into secondary alcohols
What are the benefits of reducing a carbonyl compound with HCN?
Very useful reaction as it provides a means of increasing the length of the carbon chain
What are the drawbacks of reducing a carbonyl compound with HCN?
Hydrogen cyanide is a colourless, extremely poisonous liquid that boiils slightly above room temperature so it cannot be used safely in an open lab
What reagent is used to detect the presence of a carbonyl functional group and how does it do so?
2,4-DNP (Brady’s Reagent) and in the presence of a carbonyl group, a yellow or orange precipitate is produced
What reagent is used to distinguish between aldehydes and ketones and how does it do so?
Tollens reagent, in the presence of an aldehyde a silver mirror is produced
What is a carboxyl functional group?
COOH, a group made up of a carbonyl group and a hydroxyl group
Describe the trend in solubility of carboxylic acids as the carbon chain increases
As the number of carbon atoms increases, the solubility decreases as the non-polar carbon chain has a greater effect on the overall polarity of the molecules
How can you test for a carboxyl group?
The neutralisation reaction of carboxylic acids with carbonates provides a method of distinguishing carboxylic acids from any other organic compound
How do you name an ester?
Remove the -oic acid from the parent carboxylic acid and replace with -oate and the alkyl chain attached to the oxygen atom of the COO group is the first word in the name
How do you name an acyl chloride?
Remove the -oic acid suffix from the parent carboxylic acid and replace with -oyl chloride
What is an esterfication reaction with a carboxylic acid?
A reaction of an alcohol with carboxylic acid to form an ester
