In the following halogenated organic compounds the one with maximum number of chlorine atoms in its structure is:

Step 1: Identify structures and count Cl atoms

(a) Chloral:

Formula: $\ce{CCl3-CHO}$ (Trichloroacetaldehyde)

Chlorine atoms: 3

(b) Gammaxene:

Also known as Lindane or BHC (Benzene hexachloride)

Formula: $\ce{C6H6Cl6}$

Structure: Cyclohexane ring with 6 Cl atoms (one on each carbon)

Chlorine atoms: 6 ✓✓✓

(c) Chloropicrin:

Formula: $\ce{CCl3-NO2}$ (Trichloronitromethane)

Chlorine atoms: 3

(d) Freon-12:

Formula: $\ce{CCl2F2}$ (Dichlorodifluoromethane)

Chlorine atoms: 2

Step 2: Compare

• Chloral: 3 Cl
• Gammaxene: 6 Cl (maximum)
• Chloropicrin: 3 Cl
• Freon-12: 2 Cl

Answer: (b) Gammaxene (6 chlorine atoms)

Key Compounds:

Gammaxene (Lindane):

• Insecticide
• γ-isomer of benzene hexachloride
• Formula: $\ce{C6H6Cl6}$
• Banned in many countries (persistent organic pollutant)

Chloral:

• $\ce{CCl3CHO}$
• Used to make chloral hydrate (sedative)
• 3 Cl atoms

Chloropicrin:

• $\ce{CCl3NO2}$
• Tear gas, fumigant
• 3 Cl atoms

Freon-12:

• $\ce{CCl2F2}$
• CFC refrigerant
• 2 Cl, 2 F atoms
• Ozone depleter