Chapter 26: Compounds containing the carbonyl group

What is the carbonyl group?

carbon double bonded to an oxygen

what are aldehydes oxidised to?

carboxylic acids

Why can't ketones be easily oxidised?

Unlike carboxylic acids, a C-C

What are ketones and carboxylic acids reduced to?

Alcohols

What type of alcohol are aldehydes reduced to?

Primary alcohols

What type of alcohol are ketones reduced to?

Secondary

When carboxylic acids are attached to a benzene ring, what suffix is used?

-carboxylic acid

Are carboxylic acids soluble in water?

Yes

Acid + metal oxide

salt + water

Acid + metal carbonate

salt + water + carbon dioxide

What type of catalyst is used in the reaction to produce an ester from a carboxylic acid?

Strong acid catalyst

If fats and oils are hydrolysed in acid conditions, what are the products?

A mixture of glycerol and the component fatty acids

What is acylation?

The process by which the acyl group is introduced into another molecule

What is the general formula of an acid chloride?

RCOCl

What is the general formula of an acid anhydride?

RCOOCOR'

What type of reaction is nucleophile + acyl chloride or acid anhydride?

Addition-elimination

Acid derivative + alcohol

Ester

Acid derivative + water

Carboxylic acid

Why are the boiling points of aldehydes higher than those of alkanes of comparable molecular mass

Dipole-dipole forces due to the strongly polar C=O bond

Do aldehydes have hydrogen bonds?

yes

What is the most typical reaction of the carbonyl group?

Nucleophilic additions

What do strong oxidising agents oxidise ketones to?

A shorter chain molecule, carbon dioxide and water

What precipitate forms when an aldehyde is warmed with Fehling's solution?

A brick red precipitate of copper (I) oxide

What is the formula for Tollens' reagent?

[Ag(NH₃)₂]⁺

give the two half equations when an aldehyde reacts with Tollens' reagent

RCHO + [O] → RCOOH
[Ag(NH₃)₂]⁺ + e⁻ → Ag + 2NH₃

What is used to represent a reducing agent in equations?

[H]

What apparatus can be used to find the melting point of a carboxylic acid?

Thiele tube

Acid + metal

salt + hydrogen

Carboxylic acids react with what to form esters?

Alcohols

When water reacts with an ester, what is formed?

Carboxylic acid + alcohol

What is the systematic name for glycerol?

Propane-1,2,3-triol

How can fats and oils be hydrolysed?

In acid conditions or by boiling with sodium hydroxide

If fats and oils are hydrolysed by boiling with NaOH, what are the products?

Glycerol and a mixture of sodium salts of the three acids

What are these salts?

Soap

How does RCOO⁻ work as soap?

The long hydrocarbon chain is non-polar and mixes with grease. The COO⁻ is polar and mixes with water. It allows grease and water to mix and is therefore used as cleaning agents

What are 4 uses of glycerol?

- pharaceutical and cosmetic preparations. It attracts water and so is used to prevent ointments and creams from drying out
- solvent in many medicines
- solvent in the food industry
- plasticiser

List the nucleophiles acyl chlorides and acid anhydrides will react with in order of reactivity

Primary amine > ammonia > alcohol > water

Acid derivative + ammonia

Amide

Acid derivative + amine

N-substituted amide