ECAT Pre Engineering Chemistry Chapter 23 MCQ Test With Answer

Which reaction is of condensation or addition elimination reaction?

• Ketol A
• Aldol B
• Cannizzaro C
• All of these D

On heating acetaldehyde with ammonical silver nitrate solution, we get

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

A nucleophilic reagent will readily Attack

• Ethylene A
• Ethanal B
• Ethanol C
• Ethylamine 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

At room temperature formaldehyde is

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

The carbon atom of a carbonyl group is

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

• Br_2(aq) A
• 2, 4-dinitrophenylhydrazine B
• NaBH C
• Tollen's reagent D

Cannizzaro's reaction in not given by

• Formaldehyde A
• Acetaldehyde B
• Benzaldyhyde C
• Trimethylacetaldehyde 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

In carboxyl group the bond between C and oxygen is:

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

Calcium acetate when dry distilled gives

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

Silver mirror test is applied for

• Aldehydes A
• Alcohols B
• Acids C
• Esters 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

A food chemist wants to create the odour of pineapples for a product. An ester with this odour has the formula C₃H₇COOC₂H_5.Which pair of reagents would produce this ester

• C₂H₅CI and C₃H₇COOH A
• C₂H₅OH and C₃H₇CONH₂ B
• C₂H₅OH and C₃H₇COOH C
• C₃H₇OH and C₂H₅COCI 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

Which of the following react with NaOH to produce an acid and an alcohol?

• NCHO A
• CH₃COOH B
• CH₃CH₂COOH C
• C₆H₅COOH D

In formadaldehyde and KOH are heated then we get

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

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

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

From which of the following tertiary butyl alcohol is obtained by the action of methyl magnesium iodide?

• HCHO A
• CH₃CHO B
• CH₃COCH₃ C
• CO₂ D

Which of the following compounds will react with reagent ?

• CH₃ CO H A
• CH₃ CO CH₃ B
• CH_{3 COOH} C
• CH₃ CO CH₂CH₃ 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

During the mechanism of aldol condensation a/an ______ is formed

• Oxide A
• Alkali B
• Alkoxide ion C
• None of these D

Aldehydes can be distinguished from ketones by

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

Tollen's reagent is

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

The product of the reaction between propanone and HCN is hydrolysed under acidic conditions. What is the formula of the final product

• CH₃CH(OH)COOH A
• CH₃CH₂CH(OH)COOH B
• (CH₃)₂C(OH)COOH C
• CH₃CH₂CH₂COOH D

Aromatic aldehydes undergo disproportionation in presence of sodium or potassium hydroxide to give corresponding alcohol and acid. The reaction is known as

• Wurtz reaction A
• Cannizzaro reaction B
• Friedel Craft reaction C
• Claisen reaction 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