Free Chemistry of Hydrocarbons MCQs with Answers

• A. 3-Methyl-1,4 heptyne
• B. 3-Methyl-1,4 heptadiene
• C. 5-Methyl-3,6 heptyne
• D. 5-Methyl-3,6 heptadiyne

Explanation: The correct IUPAC name for the given compound is 3-Methyl-1,4 heptadiene.

• A. Alkane
• B. Alkene
• C. Alkyne
• D. Cycloalkane

Explanation: Alkynes exhibit SP hybridization because they form 2 sigma bonds with 2 adjacent carbon atoms and the remaining two p-orbitals of each…

• A. Solid
• B. Liquid
• C. Gas
• D. None

Explanation: The correct answer is Option C: Gas. Alkynes have a relatively lower boiling point which increases with the number of carbon atoms.

• A. Increases
• B. Decreases
• C. Remain constant
• D. Fluctuate

Explanation: When the molecular structure of alkynes becomes more complex, the molecular weight increases, leading to stronger London dispersion…

• A. Lower
• B. Higher
• C. Moderate
• D. No change

Explanation: Alkynes have a higher boiling point than alkanes because of their linear structure and triple bond, resulting in stronger intermolecular…

• A. Polar
• B. Non polar
• C. Both
• D. None

Explanation: The hybridisation of Alkynes contributes to their non-polar nature, as they are highly soluble in non-polar reagents and organic…

• A. Polar
• B. Non polar
• C. Both
• D. None

Explanation: Alkynes are slightly polar because of the electronegativity difference between carbon and hydrogen, leading to a small dipole moment.

• A. CH4
• B. C2H2
• C. C2H6
• D. C2H4

Explanation: Acetylene (C2H2) is the correct answer because it is commonly utilized in welding due to its high heat production when burned with oxygen.

• A. Hydrochloric acid
• B. Oxalic acid
• C. Acetic acid
• D. Formic acid

Explanation: The correct answer is Oxalic acid. Alkynes oxidize into vicinal diketones (1,2 diketones) and are then further oxidized into carboxylic…

• A. Glucose
• B. Oxalic acid
• C. Formic acid
• D. Acetic acid

Explanation: During ozonolysis of ethyne, the triple bond is cleaved, resulting in the formation of a single carbon atom containing carboxylic acid…

• A. Sodium succinate
• B. Sodium fumarate
• C. Both of the above
• D. None of the These

Explanation: In Kolbe's electrolysis, acetylene is indeed produced at the anode by the electrolysis of Sodium/Potassium maleate or fumarate.

• A. Acidic medium
• B. Acid and HgSO4
• C. Alkaline medium
• D. neutral medium

Explanation: Water can be added across a triple bond in alkynes in the presence of mercuric Sulfate and acid.

• A. Propyl hydrogen sulphate
• B. Propanone
• C. Propanal
• D. Propanol

Explanation: All alkyl except for Ethyne when treated with Acidified HgSO4 will form their respective ketones.

• A. Benzene
• B. Ethyl benzene
• C. Propyl benzene
• D. Mesitylene

Explanation: The polymerization product of propyne is mesitylene, also known as 1,3,5-trimethylbenzene.

• A. Ethyl hydrogen sulfate
• B. Methoxymethane
• C. Ethanal
• D. Ethanol

Explanation: The correct product formed in the reaction of ethyne with dilute H2SO4 and Hg2+ is Ethanal.

• A. Formic acid
• B. Formaldehyde
• C. Acetaldehyde
• D. Acetic acid

Explanation: When ethyne reacts with HgSO4 and H2SO4, it forms acetaldehyde, which is a two-carbon aldehyde.

• A. Pent-1-yne
• B. Propyne
• C. Ethyne
• D. But-1-yne

Explanation: Propyne is the correct answer as it is commonly used as a rocket fuel. It packs a lot of energy in its triple bond and has no significant…

• A. Pyrogallol
• B. Charcoal powder
• C. Concentrated H2SO4
• D. Ammoniacal Cu2Cl2

Explanation: When alkynes react with ammoniacal Cu2Cl2, alkynides are formed which aid in the separation process.

• A. Alcohols
• B. Ketones
• C. Aldehydes
• D. Other alkynes

Explanation: Alcohols cannot be converted into alkynes because they lack the necessary functional groups for alkyne formation.

• A. Potassium chlorate
• B. Potassium permanganate
• C. Potassium dichromate
• D. Potassium chloride

Explanation: Alkynes undergo oxidation to form carboxylic acids, a process that requires strong oxidizing agents.