6.4

Question 1

What is an alcohol

Answer 1

A homologous series of compounds with general formula of CnH2n+1OH

Question 2

what is combustion

Answer 2

reaction with oxygen to form Carbon dioxide and water

Question 3

what is dehydration reaction

Answer 3

reaction with the removal of the hydroxyll group in an alcohol molecule, together with a hydrogen atom from an adjacent carbon atom forming a C=C double bond alkene

Question 4

what does a dehydration reaction require

Answer 4

Reaction involves the use of an acid catalyst either sulfamic acid or phosphuric acid

Question 5

Dehydration chemical equation

Answer 5

Ethanol = Ethene + water

Question 6

What is halogenation

Answer 6

Reaction results in the replacement of the hydroxyll group in an alcohol molecule by a halogen atom

Question 7

what is chlorination

Answer 7

Carried out by reacting alcohol with phosphurus (V) chloride where it doesn’t require heating as it’s already a vigrous reaction at RTP. The products formed are phosphurus oxychloride + HCL + halogenoalkane

Question 8

Chlorination in tertiary alcohol

Answer 8

Alcohol is reacted with concentrated HCL

Question 9

what is bromination

Answer 9

Carried out by reacting pottasuim bromide with 50% concentrated sulphuric acid. It forms hydrogen bromide as well as either pottasuim hydrogensulphate or pottasuim sulphate.The hydrogen bromide is then warmed with the alcohol

Question 10

What is iodination

Answer 10

Includes reacting red phosphorus with iodine to form phosphurus iodide. This is then reacted with alcohol to form phosphuric acid a halogenoalkane

Question 11

what is oxidation reaction in alcohols

Answer 11

Reaction where alcohols are converted into aldehydes and ketones by removing hydrogen

Question 12

What are aldehydes

Answer 12

Are a homologous series of organic compunds formed by the partial oxidation of primary alcohols and contain the functional group COH.

Question 13

what happens in the oxidation of a primary alcohol to form an aldehyde

Answer 13

the alcohol is heated and reacted with acidified potassuim dichromates which is an oxidising agent and acts as a source of oxygen. We must distill it immediately to prevent any side reactions.

Question 14

what is a carboxylic acid

Answer 14

a homologous series which is made by futher oxidation of an aldehyde and contains the functional group COOH

Question 15

what happens in the oxidation reaction of a primary alcohol to form a carboxylic acid

Answer 15

An aldehyde is oxidised by reacting it with potassuim dichromate.

Question 16

what is the different in the oxidation reactions of carboxylic acids

Answer 16

in the oxidation reaction of a carboxylic acid there is an addition of oxygen atoms rather than the removal of hydrogen atoms

Question 17

what is a ketone

Answer 17

A homologous series of organic compounds formed by oxidation reaction of secondary alcohols and have a functional group of C=O

Question 18

What is the process of oxidising a secondary alcohol to form ketones

Answer 18

the alcohol is reacted with potasuim dichromate to form a ketone and wate. It then must be heated under reflux

Question 19

What is heating under reflux

Answer 19

• Involves heating a reaction mixture with a condenser fitted vertically
• Used to obtain ketone or carboxylic acid
• Oxidation products stay in the reaction mixture

Question 20

what is distillation with addition

Answer 20

• Involves heating a reaction mixture by adding another liquid and distilling off the product as it forms
• Used to obtain aldehydes
• Only the oxidising agent is heated and alcohol is slowly added to the oxidising agent
• when the aldehyde is formed it immediately distills off (it has much slower boiling temperature rather than the alcohol used to make it) and is collected in the reciever