Free Classification of Organic Compounds MCQs with Answers
108 Classification of Organic Compounds MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Organic compounds are classified by carbon skeleton into open-chain, branched-chain and cyclic compounds, including homocyclic and heterocyclic types. The classification also uses functional groups to distinguish hydrocarbons, halo compounds, alcohols, aldehydes, ketones, carboxylic acids and their derivatives, which is different from naming compounds by IUPAC rules.
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108 questions · page 3 of 6
- A. Combustion method
- B. Dumas method
- C. Kjeldahls method
- D. All of the above methods are for different purposes
Explanation: In combustion analysis, an organic compound is burned in excess oxygen, and the carbon and hydrogen are measured from the CO2 and H2O…
Correct answer: Combustion method- A. Empirical formula
- B. Molecular mass
- C. Molecular formula
- D. Formula mass
Explanation: Combustion analysis gives the relative amounts of carbon and hydrogen, and similar analysis can give other elemental ratios.
Correct answer: Empirical formula- A. CH2 C12
- B. CH3C1
- C. CC14
- D. CHCL3
Explanation: Chloroform has the molecular formula CHCl3, and the subscripts 1:1:3 cannot be reduced by a common factor, so its empirical formula is…
Correct answer: CHCL3- A. Acyclic compound
- B. Alicyclic compound
- C. Heterocyclic compound
- D. Aromatic compound
Explanation: The homocyclic compounds which contain a ring of three or more carbon atoms and resembling aliphatic compounds are called alicyclic…
Correct answer: Alicyclic compound- A. Alicyclic and aromatic
- B. Carbocyclic and heterocyclic
- C. Acyclic and heterocyclic
- D. Heterocyclic and aromatic
Explanation: Homocyclic compounds are divided into two compounds. Alicyclic compounds and aromatic compounds.
Correct answer: Alicyclic and aromatic- A. Fats
- B. Water
- C. Carbohydrates
- D. None
Explanation: Water does not comply by the following definition: Organic compound, any of a large class of chemical compounds in which one or more atoms…
Correct answer: Water- A. Pairing scheme should be same
- B. Arrangement of atoms should be same
- C. Energy should be same
- D. All are true
Explanation: The following are the characteristics of a resonance structure. The same number of paired and unpaired electrons i.e.
Correct answer: All are true- A. Aliphatic
- B. Aromatic
- C. Benzene
- D. Heterocyclic
Explanation: Alicyclic compounds are compounds that are both aliphatic and cyclic. They contain one or more all-carbon rings which may be either…
Correct answer: Aliphatic- A. Thiophene
- B. Anthracene
- C. Furan
- D. Pyrrole
Explanation: Anthracene is a Polycyclic Aromatic Hydrocarbon (PAH) with the formula C14H10.
Correct answer: Anthracene- A. Acyclic compounds
- B. Alicyclic compounds
- C. Ring compounds
- D. Closed chain compounds
Explanation: Option A is correct because aliphatic compounds are a class of organic compounds that contain carbon atoms arranged in straight chains…
Correct answer: Acyclic compounds- A. CnH2n
- B. CnH2n-2
- C. CnH2n+2
- D. None of these
Explanation: CnH2n+2 is valid only in case of saturated open chain hydrocarbons, not in case of alicyclic. So this is correct answer.
Correct answer: CnH2n+2- A. Carbocyclic
- B. Aromatic
- C. Alicyclic
- D. Both A and C
Explanation: Cyclohexane is carbocyclic because its ring is composed solely of carbon atoms.
Correct answer: Both A and C- A. 1
- B. 3
- C. 2
- D. 0
Explanation: Secondary carbon atoms are those which are further attatched with 2 other carbon atoms or 2 hydrogen atoms.
Correct answer: 2- A. Straight chain and cyclic
- B. Branched chain and alicyclic
- C. Straight chain and branched
- D. Homocyclic and alicyclic
Explanation: Aliphatic or open chain compounds are further classified as straight chain and branched compounds.
Correct answer: Straight chain and branched- A. Sulphur
- B. Nitrogen
- C. Oxygen
- D. Chlorine
Explanation: Heteroatoms in a cyclic structure must be able to form at least two covalent bonds to be part of the ring.
Correct answer: Chlorine- A. Cyclobutane
- B. Iso-butane
- C. n-Butane
- D. Toluene
Explanation: A. Alicyclic, B. Branched hydrocarbon, C. Straight chain hydrocarbon and D. Aromatic compound.
Correct answer: Cyclobutane- A. Ammonium cyanate
- B. Urea
- C. Methane
- D. Benzene
Explanation: In 1828, Friedrich Wohler synthesized urea by heating the inorganic compound ammonium cyanate.
Correct answer: Urea- A. Homocyclic compound
- B. Heterocyclic compound
- C. Carbocyclic compound
- D. Aliphatic compound
Explanation: Pyridine is classified as a heterocyclic compound because it contains a ring made of atoms of different elements, particularly nitrogen.
Correct answer: Heterocyclic compound- A. 4
- B. 5
- C. 3
- D. 6
Explanation: Living organisms are primarily composed of four major classes of large biological macromolecules, which are all organic compounds…
Correct answer: 4- A. Heterocyclic compounds
- B. Carbocyclic compounds
- C. Saturated compounds
- D. Aromatic compounds
Explanation: An alicyclic compound is defined as an organic compound, which is both cyclic and aliphatic.
Correct answer: Carbocyclic compounds