What is the Difference Between Acetonitrile and Acetone?

Acetonitrile and acetone are both organic compounds with different chemical structures and physical and chemical properties. The key difference between the two is that acetonitrile is a nitrile compound, while acetone is a ketone.

Acetonitrile:

  • Chemical formula: C2H3N
  • Molar mass: 41 g/mol
  • Contains carbon, hydrogen, and nitrogen atoms
  • Boiling point: 81.3 to 82.1°C
  • Used as a solvent in the purification of butadiene in refineries, the pharmaceutical industry, and battery manufacturing

Acetone:

  • Chemical formula: CH3CN
  • Molar mass: 8 g/mol
  • Contains carbon, hydrogen, and oxygen atoms
  • Used as a polar solvent

Despite their differences, acetone has been used as a substitute for acetonitrile in certain applications, such as the separation of peptide mixtures by reversed-phase high-performance liquid chromatography (RP-HPLC). However, the substitution of acetone for acetonitrile can affect the separation process, as it has been observed to increase peak width, shorten retention times, and increase peak tailing.

Comparative Table: Acetonitrile vs Acetone

Here is a table comparing the differences between acetonitrile and acetone:

Property Acetonitrile Acetone
Chemical Formula CH3CN CH3COCH3
Functional Group Nitrile Ketone
Molar Mass 41 g/mol 8 g/mol
Atomic Composition C, H, N C, H, O
Solvent Miscibility Miscible with water and some other organic solvents Miscible with water and other solvents
Boiling Point 82°C 56°C
Melting Point -44°C -95°C
Uses Mainly used as a solvent in the purification of butadiene, and in organic synthesis Used as a solvent, in the manufacture of pharmaceuticals, and in the production of photographic film

Acetonitrile is a nitrile compound with the chemical formula CH3CN, while acetone is a ketone with the chemical formula CH3COCH3. Acetonitrile has a molar mass of 41 g/mol, whereas acetone has a molar mass of 8 g/mol. Acetonitrile contains carbon, hydrogen, and nitrogen atoms, while acetone contains carbon, hydrogen, and oxygen atoms. Both compounds are miscible with water and other organic solvents. Acetonitrile is primarily used as a solvent in the purification of butadiene and in organic synthesis, while acetone is used as a solvent, in the manufacture of pharmaceuticals, and in the production of photographic film.