Carboxylic Acids and Amines Flashcards Preview

Chemistry Unit 3 > Carboxylic Acids and Amines > Flashcards

Flashcards in Carboxylic Acids and Amines Deck (20):
1

What state do carboxylic acids exist in?

Solids or liquids

2

What happens as the chain length of a carboxylic acid increases?

Hydrogen bonding diminishes

3

Why are carboxylic acids able to form dimers?

Because they can form hydrogen bonds

4

When are dimers unable to exist?

When in aqueous solution of carboxylic acids

5

What happens as the chain length of a carboxylic acid increases with respect to solubility?

As the chain length of the carboxylic acid increases water solubility decreases

6

What does the equal bond length (between single and double bond) between the two C-O bonds suggest?

Electrons are delocalised over the carbon and two oxygen atoms. This provides the carboxylate ion with some stability.

7

How can oxidisation be used to prepare carboxylic acids?

Oxidising an aldehyde with acidified potassium dichromate under reflux.

8

How can you prepare carboxylic acids using hydrolysation?

By hydrolysing esters, amides or nitriles by heating them under reflux with either an acid or alkali catalyst

9

What do carboxylic acids form salts with?

Metals
Carbonates
Alkalis

10

What is the reaction between ammonia and carboxylic acids?

Forms ammonium salts (subsequent heating produces amides)

11

What is the reaction between carboxylic acids and amines?

Forms amides

12

What is the effect of the very strong reducing agent, lithium aluminium hydride and the carboxylic acid?

It is reduced directly to the primary alcohol

13

What are amines?

Organic derivatives of ammonia in which one or more hydrogen atoms in ammonia has been replaced by an alkyl group.

14

What is a tertiary amine?

When three of the hydrogens have been replaces by alkyl groups.

15

What is CH3CH2NHCH3?

ethylmethylamine

16

Why do primary and secondary amines have higher boiling points than tertiary amines?

Because they can form hydrogen bonds between their molecules

17

What is the solubility of amines?

Primary, secondary and tertiary amines of short chain length can dissolve in water. Tertiary amines form H bonds with water because of their lone pair of electrons.

18

How do amines form alkaline solutions?

The nitrogen accepts a proton from the water molecule, generating alkyl ammonium ions and hydroxide ions.

19

What is the reaction between amines and mineral acids?

Form salts

20

What is the reaction between amines and carboxylic acids?

Salts, which when heated can become amides