Free Fundamental Principles of Organic Chemistry MCQs with Answers
536 Fundamental Principles of Organic Chemistry 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 chemistry begins with carbon compounds classified by carbon skeleton, saturation and functional group. Work includes identifying groups such as hydroxyl, carbonyl, carboxyl and amino, applying basic nomenclature, and distinguishing structural, geometric and optical isomers, where the same molecular formula does not necessarily mean the same structure or properties.
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Read the Fundamental Principles of Organic Chemistry notesFree MDCAT chapter notes with key terms536 questions · page 3 of 27
- 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- 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. Methane
- B. Ethanol
- C. Acetic acid
- D. Urea
Explanation: Heating ammonium cyanate causes rearrangement into urea, NH2CONH2, an organic compound containing a carbonyl group bonded to two amino…
Correct answer: Urea- A. Sodium hexadecanoate
- B. Sodium octadecanoate
- C. Sodium pentadecanoate
- D. Both A & B
Explanation: Sodium hexadecanoate and sodium octadecanoate are soaps whose anions form insoluble calcium and magnesium salts, producing curdy scum in…
Correct answer: Both A & B- A. Bromine
- B. Fluorine
- C. Chlorine
- D. Sulphur
Explanation: Ethyl mercaptan, CH3CH2SH, contains a thiol group with sulfur, so sulfur gives the compound its characteristic odour.
Correct answer: Sulphur- A. Methanamide
- B. Methanoylamine
- C. Aminoethanol
- D. Formanide
Explanation: HCONH2 is the amide derived from methanoic acid by replacing the acid hydroxyl group with NH2.
Correct answer: Methanamide- A. Nitrogen gas
- B. NH3
- C. CN‾
- D. NO
Explanation: In Lassaigne's sodium-fusion test, nitrogen in an organic compound is converted into sodium cyanide, NaCN.
Correct answer: CN‾