ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

On heating acetaldehyde with ammonical silver nitrate solution, we get

• CH₃OH A
• Silver acetate B
• HCHO C
• Silver mirror D

Aldol condensation is actually

• Electrophilic addition of carbonation A
• Electrophilic addition of carbonium ion B
• Nucleophilic addition of carbonation C
• Nuclephilic addition of carbonium ion D

Clemensen's reduction of ketones is carried out in

• H₂with Pd catalyst A
• Glycol with KOH B
• LiAIH₄in water C
• Zn-Hg with conc. HCl D

At room temperature formaldehyde is

• Gas A
• Liquid B
• Solid C
• None of the above D

An organic compound 'A' has the molecular formula C₃H₆O, it undergoes iodoform test. When saturated with HCl it gives 'B' of molecular formula C₉H₁₄O. A and B, respectively are

• Propanal and mesitylene A
• Propanone and mesityl oxide B
• Propanone and 2, 6-dimethyl-2,5-heptadien-4-one C
• Propanone and mesitylene oxide D

Which isomer of C₅H₁₁OH gives, one dehydration, the greastest number of different alkenes

• 
  A
• 
  B
• 
  C
• 
  D

The color of ppts formed by Benedirct's test is

• Brick red A
• Wine red B
• Yellow C
• Orange D

Cannizzaro's reaction is type of reaction:

• Self oxidation-reduction reaction A
• Disproportion reaction B
• Addition C
• A and B D

Which compound on reaction with hydrogen cyanide produces a compound with a chiral centre

• Ch₃CHO A
• CH₃CH₂COCH₂CH₃ B
• CH₃CO₂CH₃ C
• HCHO D

In 1903 Arthur Lapeworth became the first chemist to investigate a reaction mechanism. The reaction he investigated was that of hydrogen cyanide with propanone. What do we now call the mechanism of this reaction

• Electrophilic addition A
• Electrophilic substitution B
• Nucleophilic addition C
• Nucleophilic substitution D

Which one of the following reagents will distinguish between C₆H₅CHO and C₆H₅COCH₃

• Aqueous bromine A
• Phosphorus pentachloride B
• 2, 4 DNPH C
• Tollen's reagent D

Formaldehyde is used to make

• Plastics A
• Medicine B
• Antiseptic C
• All of these D

The catalytic prmoter used for the industrial preparation of acetaldehyde is

• PdCI₂ A
• CuCI₂ B
• Pd + CaCI₂ C
• None of these D

Formalin is:

• 10% solution of formaldehyde in water A
• 20% solution of formaldehyde in water B
• 40% solution of formaldehyde in water C
• 60% solution of formaldehyde in water D

Formalin is an aqueous solution of

• Furfural A
• Fluorescein B
• Formaldehyde C
• Formic acid D

Aledehydes ketones can be prepared form alcohols by their:

• Reduction A
• Oxidation B
• Decomposition C
• Synthesis D

Aldehydes can be distinguished from ketones by

• 2,4-DNPH test A
• NaHSO₃test B
• N₂H₄test C
• Tollen's test D

A compound possessingα-hydrogen atom, in the presence of dilute alkali formsβ-hydroxy aldehyde. This product on heating with dilute acid forms an unsaturated crotonaldehyde. The compound is

• CH₃CHO A
• CH₃CH₂CHO B
• CH₂= CH - CHO C
• HC = C - CHO D

Chromic acid used to oxidize

• Aldehyde A
• Ketone B
• Both a and b C
• None of these D

Which of the following compounds does not react with NaHSO₃?

• C₆H₅CHO A
• Acetophenone B
• Acetone C
• Acetaldehyde D

Aldehydes can be distinguished from ketones by using

• Schiff's reagent A
• Conc. H₂SO₄ B
• Anhy. ZnCl₂ C
• Resorcinol D

Aldehyde and small methyl ketones form crystalline ______ ppts with saturated sodium bisulphate solution

• White A
• Red B
• Yellow C
• None of these D

Acetone is prepared by

• Oxidation of n-propyl alcohol A
• Oxidation of acetaldehyde B
• Pyrolysis of calcium acetate C
• Pyrolysis of calcium acetate as well as acetic acid D

Hydrogenation of bezoyl chloride in presence of Pd on BaSO₄gives

• Benzyl alcohol A
• Benzaldehyde B
• Benzoic acid C
• Phenol D

In aldol condensation reaction, a double bond is formed between ______ and ______ carbon atoms

• αandβ A
• αandα B
• αand Y C
• None of these D

• With H₂/Ni CH₃(CH₂)₅CH₂OH A
• With H₂/Ni CH₃(CH₂)₅CH₃ B
• With NaBH₄ CH₃(CH₂)₅CH₂OH C
• With NaBH₄ CH₃(CH₂)₅CHO D

Formula of acetone is:

• HCHO A
• CH₃CHO B
• CH₃OCH₃ C
• CH₃OC₂H₅ D

Acetaldehyde is used to make

• Rubbber A
• Antiseptics B
• Phenolic resin C
• All of these D

Self condensation of acetaldehyde in the presence of dilute alkalies gives

• An acetal A
• An aldol B
• Mesitylene C
• Propionaldehyde D

A nucleophilic reagent will readily Attack

• Ethylene A
• Ethanal B
• Ethanol C
• Ethylamine D