Medincine: Esterfication & Carboxylic Acids

Question 1

Between molecules ( only ) does hydrogen bonding occur

Answer 1

H-O
H-N
H-F

Question 2

What is the trend of solubility of alcohol is in the water

Answer 2

Solubility in water decreases as length of the carbon chain increases

Question 3

Why does solubility of alcohols in water decrease as the length of the of the carbon chain increases

Answer 3

increase the carbon chain = increases the proportion of the part of the molecule that cannot take part in hydrogen bonding

Eg. CH3 OH
CH3CH2 OH

( only OH takes part in hydrogen bonding )

Question 4

Definition of a primary alcohol

Answer 4

Carbon with OH is connected to 1 other carbon

Question 5

Example of a primary alcohol

and draw

Answer 5

Ethanol

Question 6

Definition of a secondary alcohol

Answer 6

Carbon with OH is connected to 2 other carbons

Question 7

Example of a secondary alcohol

and draw

Answer 7

Propan-2-ol

Question 8

Definition of a tertiary alcohol

Answer 8

Carbon with OH is connected to 3 other carbons

Question 9

Example of a tertiary alcohol and draw

Answer 9

2-methyl propan-2-ol

Question 10

What can alcohols be oxidised to

Answer 10

Carbonyl group C=O

Question 11

What are the possible products of oxidation of alcohols depending on the alcohol you start with

Answer 11

Aldehyde
Carboxylic acid
Ketone

Question 12

What is the oxidising agent for oxidation of alcohols

Answer 12

Acidified potassium chromate (VII) solution ( K2 Cr2 O7 / H+(aq) )

Question 13

What is the product on oxidation with potassium chromate solution and a primary alcohol and by what process is the product formed

Answer 13

Carboxylic acid ( reflux & Xs [O]
Aldehyde ( distillation ) 

Eg.
1. ethanol —-> ( reflux & Xs [O] ) ethanoic acid

2. ethanol —-> ( distillation [O] ) ethanal

Question 14

What is the product and oxidation with potassium cream made to solution and a secondary alcohol and by what process is the product formed formed

Answer 14

Ketone ( reflux )

Eg.

Propan-2-ol —> ( reflux & Xs [O] ) propanone

Question 15

What is the product and oxidation with potassium cream made to solution and a tertiary alcohol and by what process is the product formed

Answer 15

Do not oxidise

Therefore no products formed

Question 16

What is the sign used for an oxidising agent

Answer 16

[O]

Question 17

What is the original colour of potassium chromate solution before any reaction

Answer 17

Orange

Question 18

What is the colour change in the oxidation of a primary alcohol with potassium chromate solution

Answer 18

Orange —> green

Question 19

What is the colour change in the oxidation of a secondary alcohol with potassium chromate solution

Answer 19

Orange —> green

Question 20

What is the colour change in the oxidation of a tertiary alcohol with potassium chromate solution

Answer 20

Orange —> Orange

Question 21

What is the functional group of an aldehyde and give an example

Answer 21

H-C=O

Eg. Ethanal

Question 22

What is the functional group of a key tone and give an example

Answer 22

C=O

Eg. Propanone

Question 23

What is the functional group of a carboxylic acid

Answer 23

O=C-OH

(cooh )

Eg. ethanoic acid

Question 24

What is the functional group of an acid anhydride

Answer 24

O=C-O-C=O

Eg. Ethanoic anhydride

Question 25

What is special about functional group acid anhydride

Answer 25

It is symmetrical and when reacted with acid ( H+ ) Forms to carboxylic acid functional groups

Question 26

What is the functional group of esters and give an example

Answer 26

O=C-O ( coo ) Eg. Methyl propanoate

Question 27

What is the functional group of ethos and give an example

Answer 27

-O- Eg. Meth -oxy- ethane

Question 28

Definition of an elimination or dehydration reaction

Answer 28

A reaction where a small molecule is removed from a larger molecule leaving and unsaturated molecule

Question 29

What are the conditions required for an elimination or dehydration reaction

Answer 29

``` Heated alumina ( Al2 O3 ) 300°C ``` Or Reflux Concentrated sulphuric acid ( H2 SO4 )

Question 30

What is the product of alcohol is undergoing elimination or dehydration

Answer 30

Alcohols —> alkene + water

Question 31

What two products are formed from the dehydration of butan-2-ol

Answer 31

* But-1-ene ( if loose OH & H on C1) * But-2-ene ( it loose OH & H on C3 ) Look at notes for more clarification

Question 32

What two ways can an eater be formed

Answer 32

1. Alcohol + carboxylic acid | 2. Alcohol + acid anhydride

Question 33

How can an Ester be formed from the reaction of an alcohol and carboxylic acid and give reaction equation

Answer 33

Reflux with concentrated H2 SO4 / HCl Alcohol + carboxylic acid Ester + water

Question 34

What is the rule for naming esters formed from the reaction of an alcohol and carboxylic acid

Answer 34

Alcohol =yl Carboxylic acid = oate Eg. Methanol + ethanoic acid methYL ethanOATE

Question 35

How can an eater be formed from the reaction of an alcohol and acid anhydride

Answer 35

Gentle warming because acid anhydride is very reactive Eg. Alcohol + acid anhydride —> Ester + carboxylic acid