ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

C₂H₅CHO and (CH₃)₂CO can be distunguished by testing with

• Phenyl hydrazine A
• Hydroxylamine B
• Fehling solution C
• Sodium bisulphate D

Formaldehyde is used to make

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

Tollen's reagent is

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

Reduction of aldehydes with HI and P gives

• Primary alcohols A
• Secondary alcohols B
• Alkanes C
• Tertiary alcohols D

Aldehydes are produce in atmosphere by

• Oxidation of secondary alcohols A
• Reduction of alkenes B
• Reaction of oxygen atoms with hydrocarbons C
• Reaction of oxygen atoms with ozone D

In carboxyl group the bond between C and oxygen is:

• Sigma bond A
• Single bond B
• Double Bond C
• Triple bond D

Aldehydes are oxidizes are to give:

• Primary alcohol A
• Sec-alcohol B
• Ter-alcohol C
• Carboxylic acid 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

In which reaction, aromatic aldehyde is treated with acid anhydride in the presence of corresponding salt of the acid to give unsaturated aromatic acid?

• Friedel-Crafts reaction A
• Perkin's reaction B
• Wurtz reaction C
• None of these D

Carboxyl compounds have functional group:

• R-C-X A
• R-CH=O B
• RCOR C
• All 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

Chromic acid used to oxidize

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

On adding sodium nitroprusside ketones give

• Red A
• Wine red B
• White C
• Orange D

• 2-chlorobutanal A
• alfa-chlorobutanal B
• 2-chlorobutyraldehyde C
• alfa- chlorobutyraldehyde D

The color of ppts formed by Fehling's test is

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

Acetone is oxidized with

• Tollen's reagent A
• Fehling solution B
• Acidic dichromate solution C
• Benedicts solution D

Which of the following is a method of converting a unsaturated ketone into unsaturated hydrocarbon?

• Aldol condensation A
• Reimer Tiemann reaction B
• Cannizaaor's reaction C
• Wolf-kishner reduction D

Cyanohydrin of which of the following forms lactic acid

• HCHO A
• CH₃COCH₃ B
• CH₃CHO C
• CH₃CH₂CH₂CHO D

Which one of the following statement is wrong regarding differences between aldehydes and ketones

• Aldehydes undergo reduction to form primary alcohols while ketones undergo reduction to form secondary alcohols A
• Aldehydes undergo oxidation to form acids having less number of carbon atoms while ketones undergo oxidation to form acids having same number of carbon atoms B
• Aldehydes give positive silver mirror test while ketones give negative -mirror test C
• Aldehydes can undergo polymerization while ketones cannot undergo polymerizarion D

The catalytic prmoter used for the industrial preparation of acetaldehyde is

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

Which of the following will have the highest boiling point?

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

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

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

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

The colour of ppts formed by Fehling's test is

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

Self condensation of acetaldehyde in the presence of dilute alkalies gives

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

Which of the following does not turn Schiff's reagent to pink?

• Formaldehyde A
• Bezaldehyde B
• Aceton C
• Methyl chloride D

Cannizzaro reaction is not given by

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

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

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