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 2 of 6
- A. Propanoic acid
- B. Acetic acid
- C. Phthalic acid
- D. Butanoic acid
Explanation: Phthalic acid is benzene-1,2-dicarboxylic acid, an aromatic dicarboxylic acid rather than a fatty acid.
Correct answer: Phthalic acid- A. Aromatic
- B. Dicarboxylic
- C. Hydrocarbons
- D. Strong acids
Explanation: Phthalic acid is benzene-1,2-dicarboxylic acid and oxalic acid is ethanedioic acid, so each contains two -COOH groups and is dicarboxylic.
Correct answer: Dicarboxylic- A. Glucose
- B. Glyceraldehydes
- C. Oligosaccharides
- D. Aldehydes and ketones
Explanation: Carbohydrates are generally defined as polyhydroxy aldehydes or ketones, or compounds that yield them on hydrolysis.
Correct answer: Aldehydes and ketones- A. Cytosine
- B. Thymine
- C. Adenine
- D. Guanine
Explanation: RNA contains uracil in place of thymine, while both nucleic acids contain adenine, guanine and cytosine.
Correct answer: Thymine- A. Duplication
- B. Transcription
- C. Replication
- D. Mutation
Explanation: Replication is the process by which DNA makes a copy of its genetic information, using each original strand as a template.
Correct answer: Replication- A. Pus cells
- B. Sperm heads
- C. 1872
- D. all of the above
Explanation: Friedrich Miescher first isolated and demonstrated nucleic material, called nuclein, from the nuclei of pus cells.
Correct answer: Pus cells- A. Glycerols
- B. Fatty acids
- C. Triesters formed from glycerol and fatty acids
- D. Tetraesters formed from glycerol and fatty acids
Explanation: Animal and vegetable fats are triglycerides, meaning triesters formed when the three hydroxyl groups of glycerol react with fatty acids.
Correct answer: Triesters formed from glycerol and fatty acids- A. Organic solvents
- B. Organic and inorganic solvents
- C. Inorganic solvents
- D. Solubility has nothing to do with lipids
Explanation: Lipids are largely nonpolar, so they dissolve in nonpolar organic solvents such as ether, chloroform and benzene, but generally do not…
Correct answer: Organic solvents- A. one monosaccharide unit
- B. No monosaccharide unit
- C. 2-9 monosaccharide unit
- D. many monosaccharide
Explanation: On acid hydrolysis, an oligosaccharide breaks into a small number of monosaccharide units, conventionally about 2 to 9 units in this…
Correct answer: 2-9 monosaccharide unit- A. Cellulose glycogen galactose
- B. Glyceraldehydes glucose peptone
- C. Glycerol phospho lipids collagen
- D. Legumin amylopectin albumin
Explanation: Cellulose, glycogen and galactose are all carbohydrates: cellulose and glycogen are polysaccharides, while galactose is a monosaccharide.
Correct answer: Cellulose glycogen galactose- A. Quantitative analysis
- B. Qualitative analysis
- C. Stoichiometry
- D. Physical chemistry
Explanation: Qualitative analysis identifies which substances or ions are present in a sample, whereas quantitative analysis determines their amounts.
Correct answer: Qualitative analysis- A. Furan
- B. Thiophene
- C. Aniline
- D. Pyridine
Explanation: A heterocyclic compound contains a ring in which at least one atom is a heteroatom such as nitrogen, oxygen or sulfur.
Correct answer: Aniline- A. tartaric acid
- B. ethyl alcohol
- C. methanol
- D. urea
Explanation: Wöhler prepared urea in the laboratory in 1828 by heating ammonium cyanate, showing that an organic compound could be made from an…
Correct answer: urea- A. Wohler
- B. Kolbe
- C. Berzilius
- D. Berthelot
Explanation: Friedrich Wöhler synthesized urea from ammonium cyanate, providing the famous early laboratory synthesis of an organic compound.
Correct answer: Wohler- A. aliphatic
- B. aromatic
- C. carboxylic acid
- D. carbohydrates
Explanation: A compound containing a benzene ring is classified as aromatic because the ring has a delocalized pi-electron system that follows aromatic…
Correct answer: aromatic- A. polar solvent
- B. non-polar solvent
- C. alkalies
- D. water
Explanation: Many organic compounds are largely nonpolar and dissolve better in nonpolar organic solvents because substances with similar polarity mix…
Correct answer: non-polar solvent- A. Oorganic compounds can be synthesized from inorganic compounds
- B. organic compounds cannot be synthesized from inorganic compounds
- C. organic compounds can be synthesized by animals
- D. organic compounds can be synthesized by plants
Explanation: Vital force theory claimed that organic compounds could be produced only by living organisms because they required a special vital force.
Correct answer: organic compounds cannot be synthesized from inorganic compounds- A. Low melting points
- B. Low vapour pressure
- C. High boiling points
- D. High electrical conductivity
Explanation: Nonpolar organic compounds have weak intermolecular forces, so less energy is needed to separate their molecules during melting and they…
Correct answer: Low melting points- A. Show tetravalency
- B. Exhibit catenation
- C. Show isomerism
- D. Can form multiple bonds
Explanation: Carbon exhibits catenation, the ability of carbon atoms to form strong C-C bonds and long chains, branched chains and rings.
Correct answer: Exhibit catenation- A. 50% KOH
- B. Lime water
- C. CaCl2
- D. Mg (CIO4)2
Explanation: Anhydrous magnesium perchlorate, Mg(ClO4)2, absorbs the water formed when an organic compound is burned, allowing the hydrogen content to…
Correct answer: Mg (CIO4)2