2nd Year Chemistry Hydrocarbons MCQs

This page is about 2nd Year Chemistry Hydrocarbons MCQs and you can get Hydrocarbons MCQs with answers here. The organic compounds which having Carbon and Hydrogen are Hydrocarbons. They are classified into Straight chain or Acyclic hydrocarbons and Closed chain or Cyclic hydrocarbons. Straight chain hydrocarbons consist of Saturated and unsaturated hydrocarbons. They have specific nomenclature. Alkanes, Alkenes, and Alkynes are different hydrocarbons. Alkanes are the hydrocarbons having a single bond. Alkenes and Alkynes consist of double and Triple bonds respectively. There are various methods to prepare them. They have unique properties, uses, and reactions. Aromatic  Hydrocarbons are those containing a benzene ring. Benzene has a special structure. Benzene is prepared in different ways. It reacts with different elements. Benzene undergoes a substitution reaction. So, this is a brief introduction to this chapter. Check the important MCQs of Aliphatic and Aromatic Hydrocarbons given below.

2nd Year Chemistry Hydrocarbons MCQs

 

KEY POINTS

 

Question#1: The extent of halogenations of alkanes depends upon the factors:

• The intensity of UV light
• The concentration of x₂  used
• Temperature
• Both a and b

Question#2: The ease of dehydration of alcohols to produce alkenes is of the order:

• Tertiary> secondary> primary
• Primary>secondary> tertiary
• Secondary < primary < tertiary
• Tertiary<secondary<primary

Question#3: The dehydrating agents that can be used for alcohol dehydration:

• P₄ O₁₀ and conc.H₂ SO₄
• H₃ PO₄
• AI₂ O₃
• All of these

Question#4: Dehydration of alcohols with conc.H₂ SO₄at 180⁰  C gives:

• Ethers
• Esters
• Alkenes
• AlkyI halides

Question#5: Ethanol with conc. H₂ SO₄ 140 ⁰C forms diethyl ether because:

• It involves low temperature and high concentration of ethanol for ether preparation
• It gets dehydrated
• It gets Dehydrogenated
• Both a and b

Question#6: Elimination of a halogen atom together with a hydrogen atom an alky halide produces:

• Alkanes
• Alkenes
• Alkynes
• Alcohols

Question#7: Dehydrohalogenation of RX occurs in the presence of :

• An alcoholic base
• An alcoholic acid
• An alcoholic salt
• An alcoholic Grignard reagent

Question#8: What type of reaction occurs between ethene and hydrogen?

• Addition
• Neutralization
• Dehydration
• Oxidation

Question#9: One mole of a hydrocarbon X reacts completely with one mole of hydrogen gas in the presence of a heated catalyst. What could be the formula of X?

• C₂ H₆
• C₃ H₈
• C₅ H₁₀
• C₇ H₁₆

Question#10: Which of the following will decolorize aqueous bromine?

• 1-pentene
• Pentane
• 2-methyl-I- butane
• Both A and B

Question#11: Which of the following test can be used for distinguishing an alkane and an alkene?

• Bromine water test
• Hydroxylation
• Ozonolysis
• Both A and B

Question#12: Baeyer’s reagent is :

• 1% alkaline KMn0₄
• 1%acidified potassium dichromate
• (R)₃ AI and TICI₄
• Liquid ammonia

Question#13: Hydroxylation of alkenes produces:

• Monohydric alcohols
• Polyhydric alcohols
• Esters
• Alkynes

Question#14: Alkenes undergo:

• Addition polymerization
• Condensation polymerization
• Addition elimination polymerization
• Both B and C

Question#15: The preparation of vegetable ghee involves:

• Halogenations
• Hydrogenation
• Hydroxylation
• Dehydrogenation

Question#16: Which compound will readily undergo sulphonation?

• Benzene
• Nitro benzene
• Toluene
• Chlorobenzene

Question#17: Benzene  is heated in the air with v₂ 0₅ at 450⁰ C it undergoes:

• Substitution reaction
• Addition reaction
• Elimination reaction
• Oxidation reaction

Question#18: Which one of the following statements is not correct about benzene?

• On hydrogenation, 208 kJ/mole is liberated
• C-H bond length in benzene is 1.09 A⁰
• The molecular mass of benzene is 78.108
• Resonance energy of benzene is 150.5 kcal/mole

Question#19: The preparation of benzene from acetylene can also be said as:

• Oxidation
• Polymerization
• Dehydration
• Condensation

Question#20: What is required other than anhydrous AℓCℓ₃, when toluene is prepared to craft reaction?

• C₆H₆
• C₆H₆ +CH₃ Cℓ
• C₆H₅ C₂ H₅
• C₆ H₅ Cℓ and CH₃ CI

Question#21: Replacement of hydrogen of benzene by alkyl group in the presence of alkyl halide and aluminum chloride is known as:

• Dow’s process
• Friedel and craft acylation
• Friedel and Craft alkylation
• Clemenson reduction

Question#22: Which one of the following radicals is called benzyl radical?

• C₆ H₅
• C₆ H₅ –  C
• C₆ H₅ -C H
• C₆ H₅ -CH₂

Question#23: Which one of the following is benzal chloride?

• C₆ H₅   -CH Cℓ
• C₆ H₅   -CHCℓ₂
• C₆ H₅ -CH =CHCℓ
• None of the above

Question#24: What is the molecular formula of Benzenetriozonide?

• C₆ H₆ O₉
• C₆ H₅ O₈
• C₆ H₅ O₉
• C₆ H₆ O₆

Question#25: The hydrolysis of Benzenetrizonide will yield three moles of:

• Glyoxime
• Benzaldehyde
• Glycol
• Glyoxal

Question#26: Most reactive compound among the following:

• Benzene
• Benzoic acid
• Nitrobenzene
• Ethylbenzene

Question#27: Total number of hybrid orbitals of all the carbon atoms in benzene are:

• 3
• 6
• 12
• 18

Question#28: Chlorination of benzene in the presence of sunlight:

• Benzyl chloride
• Hexachlorobenzene
• Benezotrichloride
• Benzal chloride

Question#29: Total number of sigma bonds in the benzene molecule is?

• 6
• 12
• 3
• 9

Question#30: The Friedel-Craft reaction will be slowest for:

• Benzene
• Toluene
• Nitrobenzene
• Phenol