Chapter 7 Carbonyl Compounds

?
  • Created by: Cat
  • Created on: 26-02-13 19:47
How do aldehydes and ketones form?
Oxidation of primary alcohols by heating with a mixture of dilute sulfuric acid and potassium dichromate (VI) produces aldehydes when the product is distilled off as it forms. Ketones form by the same process but with secondary alcohols, not primary.
1 of 8
Can you oxidise aldehydes easily? Can you oxidise ketones easily? If yes, how?
Aldehydes are easily oxidised into carboxylic acids by heating with acidified potassium dichomate (VI). Ketones are not oxidised further easily.
2 of 8
What is used to reduce carbonyls?
LiAlH4 in dry ether. In the eqation, this is written above the arrow, and the compound is said to react with 2[H] to represent the reducing agent.
3 of 8
How do you make hydrogen cyanide, and what forms when it reacts at room temperature with carbonyls?
It forms by mixing excess potassium cyanide and dilute sulfuric acid. The C=O becomes a C-OH and a -CN group is also added to form a hydroxyalkylnitrile.
4 of 8
How can you test for any carbonyl compounds?
add 2,4-dinitrophenylhydrazine to a carbonyl to form a yellow precipitate of 2,4-dinitrophenylhydrazone
5 of 8
How can you distinguish between aldehydes and ketones?
Fehling's solution and Benedict's solution both react with aldehydes but not ketones to give an orange-brown precipitate of copper(I)oxide. Aldehydes also react with Tollen's reagent to form a 'silver mirror', and ketones do not.
6 of 8
What is the triiodomethane reaction and how does it work?
It a test to show the prescence of a methyl group next to a carbonyl group in an organic molecule. It works first by substitution of I2 molecule with the H on the CH3 to form CI3, then hydrolysis with OHminus ions.
7 of 8
What is the result at the end of the triiodomethane reaction?
A yellow precipitate of CHI3 and a carboxylic acid (R-COOH)
8 of 8

Other cards in this set

Card 2

Front

Can you oxidise aldehydes easily? Can you oxidise ketones easily? If yes, how?

Back

Aldehydes are easily oxidised into carboxylic acids by heating with acidified potassium dichomate (VI). Ketones are not oxidised further easily.

Card 3

Front

What is used to reduce carbonyls?

Back

Preview of the front of card 3

Card 4

Front

How do you make hydrogen cyanide, and what forms when it reacts at room temperature with carbonyls?

Back

Preview of the front of card 4

Card 5

Front

How can you test for any carbonyl compounds?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Functional Groups resources »