2,4-Dinitrophenylhydrazine

2,4-Dinitrophenylhydrazine (also known as Brady's reagent, DNPH or 2,4-DNP) is a chemical compound often used in the detection of aldehydes and ketones. It is a red-orange solid at room temperature.

Chemical Structure

Chemical structure of 2,4-Dinitrophenylhydrazine

The chemical structure of 2,4-Dinitrophenylhydrazine consists of a phenyl group attached to a hydrazine group, with two nitro groups at the 2 and 4 positions of the phenyl ring. Its chemical formula is C_6H_3(NO_2)_2NHNH_2.

Properties

2,4-Dinitrophenylhydrazine is a red-orange solid at room temperature. It is slightly soluble in water and more soluble in ethanol and ether. It is a strong acid due to the presence of the two nitro groups, which are electron-withdrawing groups.

Uses

The primary use of 2,4-Dinitrophenylhydrazine is in the qualitative analysis of aldehydes and ketones. When an aldehyde or ketone reacts with 2,4-Dinitrophenylhydrazine, it forms a yellow, orange, or red precipitate, which can be used to confirm the presence of the carbonyl group.

Safety

2,4-Dinitrophenylhydrazine is a strong irritant and can cause burns. It is also a potential explosive, especially when dry. Therefore, it should be handled with care and stored in a cool, dry place.

See Also

• Tollens' reagent
• Fehling's solution
• Benedict's reagent