ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Self condensation of acetaldehyde in the presence of dilute alkalies gives

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

Aldehydes is distinguished from ketones by using

• Tollen's reagent A
• Benedict reagent B
• Fehling solution C
• All of the above D

Chromic acid used to oxidize

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

Which of the following does not react with phenyl hydrazine?

• Ethanol A
• Ethanal B
• Acetone C
• Acetophenone D

Which compound would undergo nucleophilic addition

• Ethene, C₂H₄ A
• Bromoethane, C₂H₅Br B
• Ethanal, CH₃CHO C
• Ethane, C₂H₆ D

Dehydration of allcohol gives:

• Alkane A
• Alkene B
• Aldehyde C
• ketone D

Formaline Contains ______% alcohol

• 80 A
• 37 B
• 8 C
• 52 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

The color of ppts formed by Fehling's test is

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

Ethanal may be converted into a three-carbon acid in a two-step process.

Which compound is the intermediate

• CH₃CO₂H A
• CH₃CN B
• CH₃CH₂CN C
• CH₃CH(OH)CN D

Which of the following will have the highest boiling point

• Methanol A
• Ethanol B
• Propanal C
• 2-hexanone D

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

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

On heating acetaldehyde with ammonical silver nitrate solution, we get

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

Formalin is an aqueous solution of

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

Wolf-kishner reduction is used for the reduction of

• Nitro compounds A
• Carboxylic acids B
• Carbonyl compounds C
• Olefins 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

A compound R has all of the following properties. It is neutral; It gives an orange precipitate with 2,4-dinitrophenythydrazine; it evolves hydrogen chloride when treated with PCI₅in the cold What could R be

• 
  A
• 
  B
• 
  C
• 
  D

Which alcohol may be oxidised to a product which react with 2,4-dinitorphenylhydrazine reagent but not with Fehling's reagent

• Butan-1-ol A
• Butan-2-ol B
• 2-methylpropan-1-ol C
• 2-methylpropan-2-ol D

The color of ppts formed by Benedirct's test is

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

Reduction of aldehydes with HI and P gives

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

Aldehydes which do not haveα-hydrogen undergo

• Aldol combination A
• Cannizzaro's reaction B
• Substitution C
• Elimination 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

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

Ketones are prepared by the oxidation of:

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

In formadaldehyde and KOH are heated then we get

• Acetylene A
• Methane B
• Methyl alcohol C
• Ethyl formate D

Reaction of Grignard's reagent with ketones gives: Reaction of Grignard's reagent with formaldehyde gives:

• Pri-alcohol A
• Sec-Alcohol B
• Ter-alcohol C
• Carboxylic 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

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

• Q and R Q and R A
• R only Q and R B
• Q and R R only C
• Q only R only D