Question

Which of the following substances is not an aromatic compound?
1. Benzene
2. Napthalene
3. Anthracene
4. Hexene
5. None of the above/ More than one of the above.

Answer 1

Correct Answer - Option 4 : Hexene

The correct answer is Hexene.

Explanation:

• In chemistry, aromaticity is a property of cyclic, planar structures with a ring of resonance bonds that gives increased stability compared to other geometric or connective arrangements with the same set of atoms.
• These molecules are very stable and do not break apart quickly to react with other substances.
• 1-Hexene is an organic compound with the formula C₆H₁₂. It is not an aromatic compound.
• It is an alkene that is classified in industry as higher olefin and an alpha-olefin, the latter term meaning that the double bond is located at the alpha position, endowing the compound with higher reactivity and thus useful chemical properties. 
  • Formula- C₆H₁₂
  • Boiling point- 63.85 °C
  • Density- 673 kg/m³
• Benzene is an aromatic compound, as the C-C bonds formed in the ring are not exactly single or double, rather they are of intermediate length.
  • Aromatic compounds are divided into two categories: benzenoids (one containing benzene ring) and non-benzenoids (those not containing benzene ring), provided they follow Huckel rule.
• Naphthalene is an organic compound with formula C₁₀H₈. It is the simplest polycyclic aromatic hydrocarbon and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass. 
  • Formula- C10H8
  • Melting point- 80.26 °C
  • Boiling point- 218 °C
  • Density- 1.14 g/cm³
  • Classification- Hydrocarbon, Polycyclic aromatic hydrocarbon, Organic compound
• Anthracene is a solid polycyclic aromatic hydrocarbon of formula C₁₄H₁₀, it consists of 3 fused benzene rings.
  • It is a component of coal tar. It is used in the production of the red dye alizarin and other dyes.
  • Anthracene is colorless but exhibits a blue fluorescence under ultraviolet radiation.
    • Formula- C14H10
    • Boiling point- 340 °C
    • Density- 1.25 g/cm³
    • Classifications- Polycyclic aromatic hydrocarbon