ATDH Organic Chemistry Fundamentals 1 — Questions and Answers
Question 1: Which functional group is characteristic of an alcohol?
- Carboxyl (-COOH)
- Hydroxyl (-OH) (Correct answer)
- Amino (-NH2)
- Carbonyl (C=O)
Correct answer: Hydroxyl (-OH)
Alcohols are defined by the hydroxyl (-OH) functional group attached directly to a carbon atom.
Question 2: What is the general molecular formula for alkanes?
- CnH2n
- CnH2n+2 (Correct answer)
- CnH2n-2
- CnHn
Correct answer: CnH2n+2
Alkanes are saturated hydrocarbons with the formula CnH2n+2, meaning each carbon forms only single bonds and carries the maximum number of hydrogens.
Question 3: Which of the following compounds is an ester?
- CH3COOH
- CH3OH
- CH3COOCH3 (Correct answer)
- CH3NH2
Correct answer: CH3COOCH3
CH3COOCH3 (methyl acetate) is an ester, identifiable by the -COO- linkage formed from a carboxylic acid reacting with an alcohol.
Question 4: Stereoisomers have the same molecular formula and connectivity but differ in:
- The number of carbon atoms
- The types of functional groups present
- The spatial arrangement of atoms (Correct answer)
- The molecular weight
Correct answer: The spatial arrangement of atoms
Stereoisomers share identical molecular formulas and bond connectivity but differ in the three-dimensional arrangement of their atoms in space.
Question 5: In an addition reaction involving an alkene, which bond is broken to allow new groups to add?
- Single C-C sigma bond
- C-H bond
- C=C pi (double) bond (Correct answer)
- C-O bond
Correct answer: C=C pi (double) bond
The pi bond of the C=C double bond breaks during addition reactions, allowing new atoms or groups to bond across what was the double bond.
Question 6: Which class of organic compounds contains a carbonyl group (C=O) with at least one hydrogen directly bonded to the carbonyl carbon?
- Ketones
- Aldehydes (Correct answer)
- Carboxylic acids
- Esters
Correct answer: Aldehydes
Aldehydes (R-CHO) have the carbonyl carbon bonded to at least one hydrogen, distinguishing them from ketones where the carbonyl is flanked by two carbon groups.
Question 7: What is the IUPAC name for the compound CH3CH2CH2OH?
- Propanol
- 1-Propanol (Correct answer)
- Ethanol
- 1-Butanol
Correct answer: 1-Propanol
CH3CH2CH2OH has a 3-carbon chain (prop-) with the hydroxyl group on carbon 1, so it is named 1-propanol.
ATDH Organic Chemistry Fundamentals 1
Which functional group is characteristic of an alcohol?