Reactions Of Alcohols Flashcards
How does the amount of energy released per mole during combustion of alcohols change with chainlength?
As the number of carbon atoms in the chain increases, the amount of energy released per mole also increases.
Describe the colour change which shows that an alcohol has been oxidised.
- Orange to green
- The dichromate (VI) ions are reduced to chromium (III) ions
What is the oxidising agent used to oxidise alcohols?
- Potassium Dichromate acidified with Sulphuric Acid
What two products can primary alcohols be oxidised to?
- Aldehydes
- Carboxylic Acids
Describe the method to preparing an aldehyde from a primary alcohol.
Use distillation to remove the aldehyde from the reaction mixture as it forms.
How would you represent the oxidising agent used in a balanced equation?
[O] —> Alcohol to Aldehyde
2[O] —> Alcohol to Carboxylic Acid
How is a Carboxylic acid prepared from a primary alcohol?
Alcohol is heated strongly under reflux conditions with an excess of acidified potassium dichromate to form Carboxylic acid and water
What is reflux?
The continuous boiling and condensing of a reaction mixture to ensure that the reaction takes place without the contents of the flask boiling dry.
What is formed when secondary alcohols are oxidised using acidified dichromate?
Ketones and water
What is the result of oxidising a tertiary alcohol with acidified dichromate?
No reaction takes place
—> solution remains orange
