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Q1. The compound which is most reactive towards electrophilic substitution is:

• Toluene
• Benzene
• Nitrobenzene
• Benzoic acid

Solution

Methyl group is an activating group. Activating groups attached to benzene ring increase the reactivity of benzene towards electrophilic substitution.

Q2. The isomer in which similar atoms or groups are present on the same side of the double bond is known as:

• Cis isomer
• Trans isomer
• Position isomer
•  Chain isomer

Solution

The isomer in which similar atoms are present on the same side of the double bond is known as cis isomer.

Q3. The intermediate conformation between Eclipsed and staggered is known as:

• Half
• Newman
• Sawhorse
• Skew

Solution

The intermediate conformation between eclipsed and staggered is known as Skew.

Q4. During nitration of benzene, the active nitrating agent is:

• NO₃^-
• NO₂^-
• NO₂⁺
• HNO₃

Solution

During nitration of benzene, the active nitrating agent is NO₂⁺.

Q5. The constituents of L.P.G. are:

• Alkenes
• Alkanes
• Arenes
• Amines

Solution

L.P.G. is a mixture of propane and butane

Q6. Cis isomer have:

• High boiling point  than trans isomer
• Lower boiling point than trans isomer
•  Same boiling point
•  None of the above

Solution

 Cis isomer have high boiling point than trans isomer due to high polarity.

Q7. A water molecule eliminated from alcohol molecule in the presence of acid is known as:

• Dehalogenation
• Dehydrohalogenation
• Acidic dehydration
• Birch reduction

Solution

A water molecule  eliminated from alcohol molecule in the presence of acid is known as Acidic Dehydration.

Q8. Propene on ozonolysis forms:

• Acetaldehyde
• Formaldehyde
• Both acetaldehyde and formaldehyde
• Acetone

Solution

Firstly an ozonide is formed              This on cleavage produces smaller molecules.

Q9. In case of  Unsymmetrical alkenes addition reaction of alkyl halides in absence of peroxide  takes place according to:

• Anti Markovnikov rule
•  Markovnikov rule
•  Kharash effect
•  Peroxide effect

Solution

In absence of Peroxide the addition takes place according to Markovnikov rule.

Q10. Addition reaction takes place in unsymmetrical alkynes according to:

• Markovnikov rule
• Anti Markovnikov rule
• Peroxide effect
• Kharasch effect

Solution

 In case of unsymmetrical alkynes addition takes place according to Markovnikov rule.

Q11. Dodecane in presence of platinum gives a mixture of:

• Heptane and pentene
• Pentane and Heptane
• Pentene and Heptene
• 2 molecules of pentane

Solution

Dodecane in presence of platinum gives a mixture of Heptane and Pentene.

Q12. Friedel Crafts reaction of benzene with ethylene in presence of HCl and anhyd. AlCl₃ gives:

• Styrene
• Stilbene
• Ethylbenzene
• 1,1-Diphenylethylene

Solution

Q13. Amongst the following groups the group that deactivates the benzene ring for electrophilic substitution is:

• Methyl
• Amino
• Hydroxy
• Chlorine

Solution

Chlorine deactivates the benzene ring.

Q14. Anti Markovnikov rule is applied only to:

• HBr
• HCl
• HI
• HF

Solution

Anti Markovnikov rule is applied to HBr and not to HCl and HI as H-Cl bond is stronger whereas H-I  bond is weaker than H-Br bond.

Q15. When acetylene is treated with HBr,the product is:

• Methyl bromide
• Ethylene bromide
• Ethyl bromide
• Ethylidene bromide

Solution

When acetylene is treated with HBr, the product is Ethylidene bromide.

Q16. Identify the correct order of reactivity in electrophilic substitution reactions of the following compounds Benzene, methyl benzene, Chlorobenzene, nitro benzene:

• 1>2>3>4
• 4>3>2>1
• 2>1>3>4
• 2>1>4>3

Solution

The correct order is 2>1>3>4.

Q17. β-elimination reaction is also known as:

•  Dehalogenation
• Birch reduction
• Dehydrohalogenation
• Acidic dehydration

Solution

This reaction is known as dehydrohalogenation and example of β-elimination reaction since hydrogen atom is eliminated from the β carbon atom (carbon atom next to the carbon to which halogen is attached).

Q18. Which of the following is not aromatic?

• Cyclopropenyl cation
• Tropylium cation
• Cyclopentadienyl cation
• Cyclopentadienyl anion

Solution

Cyclopentadienyl cation has only four electrons, therefore it is not aromatic or we can say it is antiaromatic.

Q19. Alkynes react with hydrogen halides to form:

• Vicinal halides
• Geminal halides
• Both geminal and vicinal
• Alkanes

Solution

Q20. The compound formed as a result of oxidation of ethyl benzene by KMnO₄:

• Acetophenone
• Benzoic acid
• Benzyl alcohol
• Benzophenone

Solution

Benzoic acid is formed by the oxidation of ethyl benzene by KMnO₄.

Q21. Which xylene gives only one monobromo derivative?

• o-xylene
• p-xylene
• m-xylene
• Ethyl benzene

Solution

Para-xylene gives only one paramonobromo derivative.   o-xylene will give two mononitro derivatives while m-xylene will give three isomers of the mononitro derivative. Ethyl benzene can give three mononitro derivatives.

Q22. Peroxide effect proceeds by formation of:

• Free radical
• Carbocation
• Carbanion
• Carbenes

Solution

Peroxide effect proceeds by the formation of free radical.

Q23. Alkanes having six or more carbon atoms on heating in presence of oxides of vanadium get cyclised to benzene . This reaction is known as:

• Aromatization
• Controlled Oxidation
• Pyrolysis
• Isomerization

Solution

Alkanes having six or more carbon atoms on heating in presence of oxides of vanadium get cyclised to benzene . This reaction is known as aromatization.

Q24. The chlorination of alkanes is initiated by homolysis of chlorine molecule because:

• Cl-Cl bond is stronger than C-H bond
• Cl-Cl bond is stronger than C-C bond
• Cl-Cl bond is weaker than C-H bond and C-C bond
• Cl-Cl bond is strongest bond

Solution

The chlorination of alkanes is initiated by homolysis of chlorine molecule because Cl-Cl bond is weaker bond than C-Cand C-H

Q25. Fluorination is violent, it is carried out in the presence of:

• HCl
• HNO₃
• Cu
• Ni

Solution

Fluorination is too violent hence is carried in presence of oxidizing agent like HNO₃ or HIO₃.

Q26. A compound mistakenly named 3,4-dimethylbutane should be named correctly as:

• 4-methylpentane
• 2-methylpentane
• 3-methylpentane
• 1-methylpentane

Solution

The longest chain contains 5 C-atoms. Hence named as 3-methyl pentane.

Q27. Addition of halogens to alkenes is an example of:

•  Electrophilic addition reaction
• Nucleophilic addition reaction
• Electrophilic substitution reaction
• Nucleophilic  substitution  reaction

Solution

Addition of halogens to alkenes  is an example of Electrophilic addition reaction.

Q28. Action of heat on a mixture of sodium propionate and soda lime produces:

• Methane
• Ethane
• Propane
• Ethylene

Solution

R-COONa + NaOH  Na₂CO₃ + R-H

Q29. Of the following which will have a zero dipole moment?

• 1,1-Dichloroethylene
• cis-1,2-dichloroethylene
• Trans-1,2-dichloroethylene
• Monochloroethylene

Solution

The net dipole moment becomes zero because of symmetrical structure.

Q30. The general formula of alkynes is:

• C_nH_2n+2
• C_nH_2n
• C_nH_2n-2
• C_2nH_n

Solution

The general formula of  alkynes is C_nH_2n-2.

Q31. Which of the following cannot be prepared by Kolbe's electrolysis process?

• C₃H₈
• C₄H₁₀
• C₂H₆
• C₆H₁₄

Solution

By Kolbe's electrolysis process we can prepare alkanes having even number of carbon atoms.

Q32. The function of anhydrous AlCl₃ in the Friedel-Crafts reaction is to:

• Absorb water
• Absorb HCl
• To produce electrophile
• To produce nucleophile

Solution

The function of anhydrous AlCl₃ in the Friedel-Crafts reaction is to produce the electrophile.

Q33. Addition of ozone molecule to alkene to form ozonide is known as:

• Dehydrohalogenation
• Polymerization
• Dehalogenation
• Ozonolysis

Solution

The Addition of ozone molecule to alkene to form unstable ozonide followed by reduction with zinc dust and water  to form  carbonyl compounds is known as ozonolysis.

Q34. Photochemical chlorination of alkane is initiated by  process called:

• Pyrolysis
• Homolysis
• Substitution
• Peroxidation

Solution

Photochemical chlorination follows the free radical mechanism.

Q35. Alkanes are soluble in:

• Water
• Alcohol
• Carbon Tetrachloride
• All of the above

Solution

Alkanes are non-polar in nature and hence dissolve in non -polar solvents like Carbon tetrachloride.

Q36. The compound that is more reactive towards electrophilic nitration:

• Toluene
• Benzene
• Benzoic Acid
• Nitrobenzene

Solution

Toluene is more reactive towards electrophilic nitration.

Q37. In Vicinal dihalides, the two halogens are attached to:

•  Adjacent carbon atoms
• same carbon
• terminal carbon
• middle carbon

Solution

The dihalides in which two halogens atoms are attached to the adjacent carbon atoms are called vicinal dihalides.

Q38. Trans form of alkene is:

• More polar than cis form
• Less  polar  than cis form
• Less dipole moment
•  Both (2) and (3)

Solution

Trans form of alkene is less polar than cis as the same groups are on opposite side thus lesser dipole moment.

Q39. The halogen which is most reactive in the halogenation of alkanes under sunlight is:

• Chlorine
• Bromine
• Iodine
• Fluorine

Solution

The halogen which is most reactive in the halogenation of alkanes under sunlight is Chlorine.

Q40. The polynuclear hydrocarbons possessing carcinogenic property are formed from Organic materials by:

• Incomplete combustion
• Reduction
• Ozonolysis
• Complete combustion