Join WhatsApp Icon JEE WhatsApp Group
Question 52

The major product formed when 1, 1, 1-trichloropropane is treated with aqueous potassium hydroxide is:

The compound given is 1,1,1-trichloropropane, which has the structure $$CH_{3}-CH_{2}-CCl_{3}$$. Here, the carbon atom at position 1 (the terminal carbon) is bonded to three chlorine atoms.

When treated with aqueous potassium hydroxide (KOH), this compound undergoes hydrolysis. Aqueous KOH provides hydroxide ions ($$OH-$$) that act as a nucleophile. The reaction involves the substitution of chlorine atoms by hydroxyl groups, but due to the presence of three chlorine atoms on the same carbon, the process leads to the formation of a carboxylic acid.

The mechanism proceeds as follows:

First, one hydroxide ion attacks the carbon atom bearing the chlorine atoms, replacing one chlorine atom to form an intermediate:

$$CH_{3}-CH_{2}-CCl_{3} + OH- -\gt CH_{3}-CH_{2}-CCl_{2}OH + Cl-$$

This intermediate, $$CH_{3}-CH_{2}-CCl_{2}OH$$, is unstable because it has two chlorine atoms and a hydroxyl group on the same carbon. It readily loses a chloride ion and rearranges to form a dichlorocarbene-like species, but in aqueous conditions, it undergoes further hydrolysis.

The intermediate reacts with another hydroxide ion:

$$CH_{3}-CH_{2}-CCl_{2}OH + OH- -\gt CH_{3}-CH_{2}-CCl(OH)2 + Cl-$$

Now, we have $$CH_{3}-CH_{2}-CCl(OH)2$$, which is a geminal diol with one chlorine. This compound is highly unstable and undergoes rapid hydrolysis. The chlorine atom is replaced by another hydroxyl group:

$$CH_{3}-CH_{2}-CCl(OH)2 + OH- -\gt CH_{3}-CH_{2}-C(OH)3 + Cl-$$

The resulting compound, $$CH_{3}-CH_{2}-C(OH)3$$, is a geminal triol. Geminal triols are unstable and spontaneously lose a water molecule to form the corresponding carboxylic acid:

$$CH_{3}-CH_{2}-C(OH)3 -\gt CH_{3}-CH_{2}-COOH + H_{2}O$$

Thus, the overall reaction is:

$$CH_{3}-CH_{2}-CCl_{3} + 2KOH -\gt CH_{3}-CH_{2}-COOH + 2KCl + H_{2}O$$

The product is propionic acid, which has the formula $$CH_{3}CH_{2}COOH$$.

Now, comparing with the options:

  • Option A: 2-Propanol is $$CH_{3}CH(OH)CH_{3}$$
  • Option B: Propyne is $$CH_{3}C \equiv CH$$
  • Option C: Propionic acid is $$CH_{3}CH_{2}COOH$$
  • Option D: 1-Propanol is $$CH_{3}CH_{2}CH_{2}OH$$

The major product is propionic acid, corresponding to option C.

Hence, the correct answer is Option C.

Get AI Help

Create a FREE account and get:

  • Free JEE Mains Previous Papers PDF
  • Take JEE Mains paper tests

Free JEE Topicwise Questions

JEE Atomic StructureJEE Applications of DerivativesJEE Complex NumbersJEE Fluid MechanicsJEE Alcohols, Phenols & EthersJEE Basic Principles of Organic ChemistryJEE Trigonometric FunctionsJEE Three Dimensional GeometryJEE Electromagnetic WavesJEE Redox ReactionsJEE SolutionsJEE Laws of ThermodynamicsJEE Ray OpticsJEE Organic Compounds with HalogensJEE Chemical ThermodynamicsJEE Permutations & CombinationsJEE DeterminantsJEE EMF & Circuit AnalysisJEE Aldehydes & KetonesJEE Atoms & NucleiJEE Dual Nature of Matter & RadiationJEE Electric Charges & FieldsJEE Number SystemJEE Units & MeasurementsJEE Simple Harmonic MotionJEE ElasticityJEE Alternating CurrentsJEE Practical Organic ChemistryJEE Electromagnetic InductionJEE Rotational MotionJEE Hydrocarbons - AlkynesJEE CirclesJEE Kinematics - 1D MotionJEE Purification & CharacterisationJEE Nitrogen-Containing CompoundsJEE Magnetism & Magnetic MaterialsJEE Basic Concepts in ChemistryJEE Laboratory Experiments - XIJEE Periodic Table & PeriodicityJEE Coordination CompoundsJEE Inverse Trigonometric FunctionsJEE Kinetic Theory of GasesJEE Carboxylic AcidsJEE Hydrocarbons - AlkanesJEE d and f-Block ElementsJEE StatisticsJEE LimitsJEE Laws of MotionJEE Electronic DevicesJEE Continuity & DifferentiabilityJEE Sets, Relations & FunctionsJEE Work, Energy & PowerJEE Straight LinesJEE Surface TensionJEE Vector AlgebraJEE ElectrochemistryJEE Kinematics - 2D MotionJEE Chemical KineticsJEE Magnetic Effects of CurrentJEE Binomial TheoremJEE Definite IntegrationJEE ProbabilityJEE Sequences & SeriesJEE Hydrocarbons - AromaticJEE Chemical Bonding & Molecular StructureJEE Hydrocarbons - AlkenesJEE Quadratic EquationsJEE DifferentiationJEE GravitationJEE JEE 2D GeometryJEE p-Block Elements (Groups 13-18)JEE Wave OpticsJEE BiomoleculesJEE Heat TransferJEE Current & ResistanceJEE MatricesJEE Differential EquationsJEE EquilibriumJEE WavesJEE Indefinite IntegrationJEE Electric Potential & CapacitanceJEE Conic Sections
Ask AI