Free Chemistry of Hydrocarbons MCQs with Answers

• A. 1.54oA
• B. 1.34oA
• C. 1.2oA
• D. 1.39oA

Explanation: C−C bond length in benzene is 1.39 ˚A.The bond length C-C ( single bond as in ethane ) is 1.54 Å and C=C ( double bond as in ethene is…

• A. C6H6 + CH4
• B. C6H5Cl
• C. C6H6 + CH3Cl
• D. C6H5Cl + CH4

Explanation: In the Friedel-Crafts synthesis of toluene, the reactants in addition to anhydrous AlCl3 are benzene (C6H6) and methyl chloride (CH3Cl).

• A. Biphenyl
• B. Dimethyl Ketone
• C. Diphenyl Ketone
• D. Methylphenyl Ketone

Explanation: Benzophenone is a widely used building block in organic chemistry, being the parent diarylketone. Benzophenone. Names.

• A. 2
• B. 3
• C. 4
• D. 5

Explanation: Xylene is an aromatic hydrocarbon with a single ring and two methyl groups attached to this ring in positions 1-2, 1-3 and 1-4, called…

• A. C10H8
• B. C10H10
• C. C10H12
• D. C12H12

Explanation: The chemical formula for naphthalene is C 10 H 8 . Naphthalene's chemical formula indicates that a single naphthalene molecule is composed…

• A. Chlorobenzene
• B. Benzoyl chloride
• C. Ortho-para dichlorobenzene
• D. Hexachlorobenzene

Explanation: When benzene is heated with chlorine in the presence of sunlight , it form benzene hexachloride.

• A. Resonance
• B. Inductive effect
• C. Both (a) and (b)
• D. Unpredictable

Explanation: The reaction of a substituted ring with an activating group is faster than benzene.

• A. Naphthalene
• B. Phenanthrene
• C. Anthracene
• D. Triphenylmethane

Explanation: Isolated Benzenoid Hydrocarbons: In isolated systems, two or more rings are joined to each other directly or through carbon chain.

• A. More π-bonds
• B. Localized π-electrons
• C. Delocalized π-electrons
• D. More σ-bonds

Explanation: It undergoes resonance via π electron delocalization. Thus, the presence of 3 π bonds makes it less reactive and more stable than ethene…

• A. -OH
• B. -OCH3
• C. -CHO
• D. -NH2

Explanation: OH and - NHCOCH 3 are ortho and para directing groups. These are also the electron donating groups and the attack of the incoming groups…

• A. Phenol
• B. Benzene
• C. Nitrobenzene
• D. Chlorobenzene

Explanation: Sulphonation of phenol at high temperature gives predominantly para isomer i.e. 4-phenol sulphonic acid.

• A. 3
• B. 4
• C. 5
• D. 6

Explanation: In Kekule's structure, the carbon atoms in benzene are arranged in a hexagonal ring with each carbon atom is attached to two other carbon…

• A. Paraffins
• B. Alkene
• C. Benzene
• D. Cyclohexane

Explanation: In the International Union of Pure and Applied Chemistry (IUPAC) system, aromatic hydrocarbons such as those above are named as…

• A. Atomic orbital treatment of benzene
• B. Resonance method
• C. Both (a) and (b)
• D. None

Explanation: By virtue of resonance, the benzene molecule is stabilized; the pi electrons are delocalized around the ring structure.

• A. Isomerization
• B. Aromatization
• C. Dealkylation
• D. Rearrangement

Explanation: Aromatization is a chemical reaction in which an aromatic system is formed from a single nonaromatic precursor.

• A. A
• B. B
• C. C
• D. D

Explanation: The benzyl free radical has the formula C 6H 5CH 2•. The benzyl cation or phenylcarbenium ion is the carbocation with formula C 6H 5CH+2…

• A. dil. NaOH
• B. dil. HNO3
• C. Conc. HNO3
• D. Acidified KMnO4

Explanation: Toluene should be heated in presence of acidified \[KMn{O_4}\] to carry out oxidation of Toluene.

• A. Dewar
• B. Faraday
• C. Down
• D. Kekule

Explanation: German chemist August Kekulé visualized the ring structure of benzene in 1865.

• A. Three double bonds
• B. Two double bonds
• C. One double bond
• D. Delocalized π-electron charge

Explanation: Benzene is an organic chemical compound with the molecular formula C6H6.

• A. Normal series of paraffins
• B. Alkene
• C. Benzene
• D. Cyclohexane

Explanation: In the International Union of Pure and Applied Chemistry (IUPAC) system, aromatic hydrocarbons such as those above are named as…