6.4 Flashcards
Alcohols
What is an alcohol
A homologous series of compounds with general formula of CnH2n+1OH
what is combustion
reaction with oxygen to form Carbon dioxide and water
what is dehydration reaction
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
what does a dehydration reaction require
Reaction involves the use of an acid catalyst either sulfamic acid or phosphuric acid
Dehydration chemical equation
Ethanol = Ethene + water
What is halogenation
Reaction results in the replacement of the hydroxyll group in an alcohol molecule by a halogen atom
what is chlorination
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
Chlorination in tertiary alcohol
Alcohol is reacted with concentrated HCL
what is bromination
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
What is iodination
Includes reacting red phosphorus with iodine to form phosphurus iodide. This is then reacted with alcohol to form phosphuric acid a halogenoalkane
what is oxidation reaction in alcohols
Reaction where alcohols are converted into aldehydes and ketones by removing hydrogen
What are aldehydes
Are a homologous series of organic compunds formed by the partial oxidation of primary alcohols and contain the functional group COH.
what happens in the oxidation of a primary alcohol to form an aldehyde
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.
what is a carboxylic acid
a homologous series which is made by futher oxidation of an aldehyde and contains the functional group COOH
what happens in the oxidation reaction of a primary alcohol to form a carboxylic acid
An aldehyde is oxidised by reacting it with potassuim dichromate.
what is the different in the oxidation reactions of carboxylic acids
in the oxidation reaction of a carboxylic acid there is an addition of oxygen atoms rather than the removal of hydrogen atoms
what is a ketone
A homologous series of organic compounds formed by oxidation reaction of secondary alcohols and have a functional group of C=O
What is the process of oxidising a secondary alcohol to form ketones
the alcohol is reacted with potasuim dichromate to form a ketone and wate. It then must be heated under reflux
What is heating under reflux
- Involves heating a reaction mixture with a condenser fitted vertically
- Used to obtain ketone or carboxylic acid
- Oxidation products stay in the reaction mixture
what is distillation with addition
- 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
