Naming and Forming Aldehydes and Ketones

What functional group do aldehydes and ketones contain?

Carbonyl group (C=O).

Where is the carbonyl group positioned in aldehydes?

At the end of the carbon chain.

Where is the carbonly group positioned in ketones?

In the middle of the carbon chain.

How are aldehydes named?

The suffix -al is used at the end of the name of the compound.

How are ketones named?

The suffix -one is used at the end of the name of the compound.

How are aldehydes and ketone formed?

From the oxidation of alcohols.

What type of alcohols are oxidised to aldehydes?

Primary alcohols.

What type of alcohols are oxidised to ketones?

Secondary alcohols.

What reagents / conditions are needed when oxidisng alcohols to aldehydes / ketones?

• An oxidising agent- acidified potassium dichromate (VI) or acidified potassium manganate (VII) is used.

• The reaction mixture needs to be warmed, preferably in a water bath since alcohols are flammable.

What problem arises when oxiding primary alcohols to aldehydes?

The aldehyde can be further oxidised into a carboxylic acid; it is important that the aldehyde is distilled immediately to prevent further oxidation.

What is the colour change seen when acidified potassium dichromate is oxidised?

With acidified potassium dichromate (VI) the solution will change from orange (Cr₂O₇^2-) to green (Cr³⁺) when oxidized.

What is the colour change seen when acidified potassium manganate is oxidised?

With acidified potassium manganate (VII) the solution will change from purple (MnO₄^-) to pale pink / colourless (Mn²⁺) when oxidized.

What symbol is used to represent an oxidising agent?

[O].