NEET Chemistry Hydrocarbons MCQs Set 03

Question:  When CH₃CH₂CHCl₂ is treated with NaNH₂ , the product formed is

• a) CH₃– CH = CH₂
• b) CH₃– C ≡ CH
• c)

  

• d)

  

Answer:  CH₃– C ≡ CH

Question: 2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is

• a) trans-pent-2-ene
• b) Pent-1-ene
• c) 2-ethoxypentane
• d) cis-pent-2-ene

Answer: trans-pent-2-ene

Question:  In the following reaction

the product ‘X’ is

• a) C₆H₅CH₂OCH₂C₆H₅
• b) C₆H₅CH₂OH
• c) C₆H₅CH₃
• d) C₆H₅CH₂CH₂C₆H₅

Answer:  C₆H₅CH₃

Question:  When 3, 3-dimethyl 2-butanol is heated with H₂SO₄ , the major product obtained is

• a) 2, 3-dimethyl 2-butene
• b) cis and trans isomers of 2, 3-dimethyl 2-butene
• c) 2, 3-dimethyl 1-butene
• d) 3, 3-dimethyl 1-butene

Answer: 2, 3-dimethyl 2-butene

Question:  Identify Z in the sequence of reaction

• a)

  

• b) CH₃– CH₂– CH₂– CH₂– Br
• c)

  

• d) None of these

Answer:  CH₃– CH₂– CH₂– CH₂– Br

Question:  In the following reaction

The major product is

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  What products are formed when the following compound is treated with Br₂ in the presence of FeBr₃?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: One of the following which does not observe the anti-Markownikoff’s addition of HBr, is

• a) Pent-2-ene
• b) Propene
• c) But-2-ene
• d) But-1-ene

Answer: But-2-ene

Question:  Which of the compounds with molecular formula C₅H₁₀ yields acetone on ozonolysis?

• a) 3-methylbut-1-ene
• b) Cyclopentane
• c) 2-methylbut-1-ene
• d) 2-methylbut-2-ene

Answer: 2-methylbut-2-ene

More Questions............................................

Question:  In preparation of alkene from alcohol using Al₂O₃ which is the effective factor?

• a) Porosity of Al₂O₃ 
• b) Temperature
• c) Concentration
• d) Surface area of Al₂O₃

Answer: Temperature

Question: Dihedral angle in staggered form of ethane is

• a) 0° 
• b) 120°
• c) 60°
• d) 180°

Answer: 60°

Question: 2-butene shows geometrical isomerism due to

• a) Restricted rotation about double bond
• b) Free rotation about double bond
• c) Free rotation about single bond
• d) Chiral carbon

Answer: Restricted rotation about double bond

Question: Gammexane is

• a) Bromobenzene
• b) Benzyl Chloride
• c) Chlorobenzene
• d) Benzene hexachloride

Answer: Benzene hexachloride

Question: In Friedel-Crafts reaction, toluene can be prepared by

• a) C₆H₆+ CH₃Cl 
• b) C₆H₅Cl + CH₄
• c) C₆H₆+ CH₂Cl₂   
• d) C₆H₆+ CH₃COCl

Answer:  C₆H₆+ CH₃Cl 

Question:  When acetylene is passed through dil. H₂SO₄ in the presence of HgSO₄ , the compound formed is

• a) Acetic acid
• b) Ketone
• c) Ether
• d) Acetaldehyde

Answer: Acetaldehyde

Question: In the commercial gasolines, the type of hydrocarbons which are more desirable is

• a) Linear unsaturated hydrocarbon
• b) Toluene
• c) Branched hydrocarbon
• d) Straight-chain hydrocarbon

Answer: Branched hydrocarbon

Question: Which one of these is not compatible with arenes?

• a) Electrophilic additions
• b) Delocalisation of π-electrons
• c) Greater stability
• d) Resonance

Answer: Electrophilic additions

Question: The cylindrical shape of alkyne is due to

• a) Two sigma C–C and one π C–C bonds  
• b) One sigma C–C and two π C–C bonds
• c) Three sigma C–C bonds   
• d) Three π C–C bonds

Answer:  One sigma C–C and two π C–C bonds

Question: Which of the following is used as an anti-knocking material?

• a) Glyoxal
• b) Freon
• c) T.E.L.
• d) Ethyl alcohol

Answer: T.E.L.

Question: The bond length between central carbon atom and other carbon atom is minimum in

• a) Propene
• b) Propyne
• c) Propane
• d) Pentane

Answer: Propyne

Question: Geometrical isomers differ in

• a) Position of functional group
• b) Position of atoms
• c) Spatial arrangement of atoms
• d) Length of carbon chain

Answer: Spatial arrangement of atoms

Question: Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by

• a) Oxidation
• b) Cracking
• c) Distillation under reduced pressure
• d) Hydrolysis

Answer: Cracking

Question: Eclipsed form of ethane has higher energy due to

• a) Torsional strain
• b) Steric strain
• c) Angle strain
• d) Both (1) & (2)

Answer: Both (1) & (2)

Question: The difference in potential energy between eclipsed and staggered form of ethane is

• a) 4 kJ/mol
• b) 12.55 kJ/mol
• c) 2 kJ/mol
• d) 44 kJ/mol

Answer: 12.55 kJ/mol

Question: Which one is most stable?

• a) Cyclopropane
• b) Cyclobutane
• c) Cyclopentane
• d) Cyclohexane

Answer: Cyclohexane

Question: In iodination ; for preparation of iodomethane compound used is

• a) HIO₃
• b) HgO
• c) Both (1) & (2)
• d) HI

Answer: Both (1) & (2)

Question:  In chlorination the relation rate of abstraction of H in 3°, 2° and 1°C atom respectively

• a) 5 : 3.8 : 2
• b) 5 : 3.8 : 1
• c) 1600 : 82 : 1
• d) 1600 : 5 : 82

Answer: 5 : 3.8 : 1

Question: In which alkane isomerization will not occur?

• a) C₂H₆ 
• b) C₄H₁₀
• c) C₅H₁₀
• d) C₆H₁₄

Answer:  C₂H₆ 

Question:  C₆H₅CH₂CH₂CH₃  is when oxidised in the presence of alk. KMnO₄, the product obtained is

• a) C₆H₅CHO
• b) C₆H₅COOH
• c) C₆H₅CH₂CH₂CHO
• d) C₆H₅COCH₃

Answer:  C₆H₅COOH

Question: Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by

• a) Oxidation
• b) Cracking
• c) Distillation under reduced pressure
• d) Hydrolysis

Answer: Cracking