Examkin

Soru

Zorluk: KolayAlkanals and Alkanones: Oxidation, Reduction, and Distinction Tests

Which of the following reagents reacts with propanal to produce a silver mirror, but shows no reaction with propanone?

  1. Ammoniacal silver nitrate solutionCevap
  2. B
    Fehling's solution
  3. C
    Acidified potassium dichromate(VI) solution
  4. D
    Lithium tetrahydridoaluminate(III) in dry ether

Cevap

Ammoniacal silver nitrate solution
Ammoniacal silver nitrate solution (Tollen's reagent) acts as a mild oxidizing agent. It oxidizes propanal to propanoate ions while Ag+Ag^+ ions are reduced to elemental silver, depositing as a silver mirror on the container walls. Propanone resists oxidation by mild oxidizing agents and yields no silver deposit.

Adım Adım Çözüm

1
Identify the functional groups of the given compounds
Propanal (CH3CH2CHOCH_3CH_2CHO) is an alkanal (aldehyde), whereas propanone (CH3COCH3CH_3COCH_3) is an alkanone (ketone).
Alkanals possess a terminal carbonyl group with a hydrogen atom that is easily oxidized, while alkanones lack this hydrogen atom.
2
Determine the specific reagent that yields a silver mirror
Tollen's reagent (ammoniacal silver nitrate solution, [Ag(NH3)2]+[Ag(NH_3)_2]^+) is reduced by alkanals to form metallic silver (Ag(s)Ag(s)), which deposits on the glass wall as a silver mirror.
Alkanones cannot be easily oxidized by mild oxidizing agents like Tollen's reagent under standard conditions.

Anahtar Kavram

Distinction between alkanals and alkanones using Tollen's reagent
Bu soruyu puanla

Konular

Alkanals and Alkanones: Oxidation, Reduction, and Distinction Tests

Bu konudan daha fazla soru