ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

The catalytic prmoter used for the industrial preparation of acetaldehyde is

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

Self condensation of acetaldehyde in the presence of dilute alkalies gives

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

The homologous series of aldehydes and ketones have general formula:

• C_nH_2nO A
• C_nH_nO B
• C_nH_2n-1O C
• C_nH_nO_n D

Calcium acetate when dry distilled gives

• Formaldehyde A
• Acetaldehyde B
• Acetone C
• Acetic anhydride D

The color of ppts formed by Benedirct's test is

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

Aledehydes ketones can be prepared form alcohols by their:

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

Tollen's reagent is

• Ammonical cuprous chloride A
• Ammonical cuprous oxide B
• Ammonical silver bromide C
• Ammonical silver nitrate D

Common names of aldehydes are given by corresponding:

• Ketone A
• Alcohol B
• Carboxylic acid C
• ester D

Which of the following organic compounds exhibits positive Fehling test as well as iodoform test?

• Methanal A
• Ethanol B
• Propanone C
• Ethanal D

Which of these reactions is shown by buranone, CH₃COCH₂CH₃

• On warming with acidified potassium dichromative (IV) the solution turns green A
• On heating with Fehling's reagent a red precipitate is formed B
• With 2,4-dinitrophenlhydrazine reagent an orange precipitate is formed C
• With hydrogen cyanide an aldehyde is formed D

Which of the following reactions is used for detecting presence of carbonyl group?

• Reaction with hydroxylamine A
• Reaction with hydrazine B
• Reaction with phenyl hydrazine C
• All D

Cannizzaro reaction is not given by

• Trimethyl acetaldehyde A
• Acetaldehyde B
• Benzaldehyde C
• Formaldehyde D

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

• 
  A
• 
  B
• 
  C
• 
  D

• Treatment with HCN followed by acid hydrolysis A
• Oxidation of acetaldehyde followed by basic hydrolysis B
• Treatment with HCN followed by reduction C
• Treatment with HCN followed by oxidation D

Which of the following will have the highest boiling point?

• Methanal A
• Ethanal B
• Propanal C
• 2-Hexanone D

Formalin is an aqueous solution of

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

Ketones are prepared by the oxidation of

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• None of these D

For which one of the following pairs of compounds can the members be distinguished by means of Tollen's test

• HCHO and CH₃CHO A
• CH₃CHO and CH₃COCH B
• CH₃COCH₃and C₆H₅COCH₃ C
• CH₃COOH and CH₃COOCH₃ D

Acetone reacts with HCN to form a cyanohydrin. It is an example of

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

Ketones are prepared by the oxidation of:

• Primary alcohol A
• Secondary alcohol B
• Tertiary alcohol C
• None of these D

The carbon atom of a carbonyl group is

• Sp hybridized A
• Sp²hybridized B
• Sp³hybridized C
• None of these D

Which is not true about acetophenone?

• Reacts to form 2,4-dintrophenyl hydrazine A
• Reacts with Tollen's reagent to form silver mirror B
• Reacts with I₂/NaOH to form iodoform C
• On oxidation with alkaline KMnO₄followed by hydrolysis gives benzoic acid D

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

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

When vapours of isopropyl alcohol are passed over heated copper, the major product obtained is

• Propane A
• Propylene B
• Acetaldehyde C
• Acetone D

Which of the following compounds will not give iodoform test on treatment with I₂/ NaOH?

• Acetaldehyde A
• Acetone B
• Butane C
• 3-pentanone D

Compounds X, Y and Z, all react with PCI₅to release hydrogen chloride, but only one of them reacts eith 2,4-dinitrophenylhydrazine reagent. Which one of the following combinations could be X, Y and Z

• 
  A
• 
  B
• 
  C
• 
  D

Formaline Contains ______% alcohol

• 80 A
• 37 B
• 8 C
• 52 D

Aldehydes and ketones are carbonyl compounds. Which of them react both with NaBH₄and with Tollen's reagent

• Both aldehydes and ketones A
• Aldehydes only B
• Ketones only C
• Neither aldehydes nor ketones D