Aldehydes

Question 1

Why do aldehydes have higher boiling points than alkanes but lower boiling point than alcohols and carboxylic acid?

Answer 1

The bonding that exists between aldehyde molecules is dipole-dipole attraction, which is weaker than the hydrogen bonding present in alcohol and carboxylic molecules.

Question 2

Why are aldehydes with carbon atoms less than five soluble in water?

Answer 2

They are soluble in water because hydrogen bonding is formed between the partial positively charged hydrogen of the water molecules and the partial negatively charged oxygen on the aldehydes, as well as the dipole-dipole attraction.

Question 3

How are aldehydes prepared?

Answer 3

1. By the ozonolysis of alkenes in the presence of water and zinc.
2. The oxidation of primary alcohols by using pyrinidium chlorocarbonate (PCC) or acidified potassium heptodichromate VI (K₂Cr₂O₇)

Question 4

What is the chemical equation for the ozonolysis of alkenes to form aldehyde?

Answer 4

Here.