6.1.3 carboxylic acids and esters

Question 1

what are the 3 ways carboxylic acids are made

Answer 1

-oxidation of a primary alcohol
-oxidation of an aldehyde

Question 2

how is carboxylic acid made through oxidation of a primary alcohol

Answer 2

-oxidised using acidified potassium dichromate
-firstly oxidised to aldehyde then carboxylic acid
-uses 2 (O) and 1 H2O

Question 3

what are the 2 ways carboxylic acids are made through oxidation of aldehyde

Answer 3

-aldehyde to carboxylic acid
uses 1 (O) no H2O is made
-Tollens reagent
positive test result=silver mirror

Question 4

how is carboxylic acid a weak acid

Answer 4

proton donor that partially dissociates

Question 5

what happens when we react ethanoic acid with a alkali

Answer 5

salt (carboxylate) + water

Question 6

what happens when we react ethanoic acid with a metal

Answer 6

salt + 1/2 hydrogen

Question 7

what happens when we react ethanoic acid with a metal oxide

Answer 7

2salt + water
(Two lots of carboxylic acid)

Question 8

what happens when we react ethanoic acid with a carbonate

Answer 8

2salt + water + carbon dioxide

Question 9

how is a carboxylate ion formed

Answer 9

when carboxylic acid reacts with an alkali

Question 10

are carboxylic acids soluble

Answer 10

yes due to the lone pair of electrons on the O

Question 11

what can you react a carboxylic acid with to form an ester and under which conditions

Answer 11

carboxylic acid with alcohol
-forms water
conc H2SO4

Question 12

naming an ester

Answer 12

in booklet
-c=o forms -oate include the C in the double bond

Question 13

draw the reaction between ethanol and ethanoic acid

Answer 13

in booklet

Question 16

what is the equation for an acid hydrolysis

Answer 16

ester+ water=carboxylic acid+ alcohol

Question 17

what reagent does an acid hydrolysis require

Answer 17

dilute sulphuric acid

Question 18

what is the equation for a base hydrolysis

Answer 18

ester+ NaOH (dilute alkali) =carboxylate acids+ alcohols

Question 19

how do you form an acyl chloride

Answer 19

CH3COOH + SOCl2 ———> CH3COCl + SO2 +HCl

Question 20

why will acyl chlorides react with water alcohols phenols amines and amides

Answer 20

They can behave as nucleophiles
The oxygen and nitrogen both contain a lone pair of Electrons

Question 21

what are the two ways you can prepare an ester using an acyl chloride

Answer 21

Acyl chloride plus alcohol
acyl chloride plus phenol

Question 22

How can you prepare a carboxylic acid using an acyl chloride

Answer 22

Acyl chloride plus water gives a carboxylic acid

Question 23

how can you prepare an amide using an acyl chloride

Answer 23

react acyl chloride with ammonia

Question 24

how can you prepare an ester using a acid anhydride

Answer 24

alcohol + acid anhydride——>ester+ carboxylic acid
-catalysed by concentrated H3PO4