IUPAC nomenclature including regio‑ and stereoisomers - One Line Questions
1.
In the IUPAC naming of alkynes, the suffix changes from '-ane' to: —
-yne
2.
In the IUPAC naming of alkenes, the suffix changes from '-ane' to: —
-ene
3.
What is the IUPAC name for the compound with the structure Br-CH2-CH(Cl)-CH3? —
1-Bromo-2-chloropropane
4.
What is the IUPAC name for a methyl-substituted cyclohexane where the methyl group is at position 1? —
Methylcyclohexane
5.
Which of the following pairs are regioisomers? —
But-1-ene and But-2-ene
6.
For disubstituted benzene rings, the prefixes 'ortho-', 'meta-', and 'para-' are used, indicating the relative positions of the substituents. 'Ortho' refers to positions: —
1,2
7.
What is the IUPAC name for CH3-CH(CH3)-CH2-CH3? —
2-Methylbutane
8.
What is the correct IUPAC name for (CH3)2CHCH2CH(CH3)2? —
2,4-Dimethylpentane
9.
In the IUPAC name 3-ethyl-2-methylhexane, the longest carbon chain has how many carbons? —
6
10.
What is the correct IUPAC name for CH3-CH(CH3)-CH=CH2? —
3-Methylbut-1-ene
11.
What is the IUPAC name for CH3-CH2-CH(CH3)-CH2-CH3? —
3-Methylpentane
12.
In compounds with multiple functional groups, the IUPAC nomenclature assigns priority to functional groups. Which of the following functional groups has the highest priority? —
Carboxylic acid (-COOH)
13.
In IUPAC nomenclature, what does the suffix '-ane' typically indicate? —
An alkane with single bonds between carbon atoms
14.
What is the regiochemical outcome of the addition of HBr to propene in the absence of peroxides (Markovnikov's rule)? —
Bromine adds to the internal carbon
15.
What is the IUPAC name for CH3-CH=CH-CH3? —
But-2-ene
16.
What is the IUPAC name for CH2=CH-CH2-CH3? —
But-1-ene
17.
What is the IUPAC name for CH3-C≡C-CH3? —
But-2-yne
18.
What is the IUPAC name for CH3-CH(OH)-CH2-CH3? —
Butan-2-ol
19.
A carbon atom bonded to four different groups is called a: —
Chiral center
20.
Which of the following is a pair of structural isomers? —
Propanoic acid and Methyl acetate
21.
When naming cyclic alkanes, the prefix 'cyclo-' is added to the name of the alkane with the same number of carbon atoms. What is the IUPAC name for a 6-membered ring alkane? —
Cyclohexane
22.
The term 'regioisomer' refers to isomers that have: —
Different positions of a functional group or substituent on a carbon skeleton
23.
The term 'stereoisomer' refers to isomers that have: —
The same connectivity of atoms but different spatial arrangements
24.
What is the IUPAC name for CH3-COOH? —
Ethanoic acid
25.
What is the correct IUPAC name for CH3-CH2-CH3? —
Propane
26.
What is the IUPAC name for CH3-CHO? —
Ethanal
27.
Enantiomers are stereoisomers that are: —
Non-superimposable mirror images of each other
28.
What is the IUPAC name for a benzene ring with a single methyl group attached? —
Methylbenzene
29.
For a cyclic compound with a double bond and a substituent, the carbon of the double bond is given the lowest possible locant, usually 1. What is the IUPAC name for a six-membered ring with one double bond and a methyl group? —
1-Methylcyclohexene
30.
When multiple identical substituents are present in a branched alkane, what prefixes are used in IUPAC nomenclature? —
mono-, di-, tri-
31.
What is the IUPAC name for a benzene ring with two methyl groups at positions 1 and 3? —
1,3-Dimethylbenzene
32.
A racemic mixture is a mixture containing: —
Equal amounts of two enantiomers
33.
In E/Z notation, 'Z' configuration indicates that the higher priority groups are on: —
The same side of the double bond
34.
The IUPAC name for the compound where a benzene ring is attached to a CH2OH group is: —
Benzenemethanol
35.
Which of the following is a type of stereoisomerism? —
Geometric isomerism
36.
What is the IUPAC name for CH3-CO-CH3? —
Propanone
37.
The presence of a stereocenter in a molecule generally leads to: —
Optical isomerism (enantiomers)
38.
Geometric isomerism arises due to restricted rotation around a bond, commonly found in: —
Double bonds in alkenes and in rings
39.
The addition of HBr to propene can result in two possible products. The product where the bromine atom attaches to the second carbon atom is an example of: —
Regioisomerism (Anti-Markovnikov's rule)
40.
Which of the following is NOT a type of isomerism? —
Isotopism
41.
Chirality is a property of molecules that are: —
Non-superimposable on their mirror image
42.
What does the term 'E/Z' notation in stereochemistry describe? —
The relative positions of substituents around a double bond
43.
For branched alkanes, the numbering of the carbon chain should begin from the end that gives the substituent(s) the lowest possible number. This principle is known as: —
The lowest locant rule
44.
For alkenes, the numbering of the carbon chain should begin from the end nearer to the double bond to give the double bond the lowest possible locant. This principle is known as: —
The lowest locant rule for unsaturation
45.
According to IUPAC rules, what is the base name of a hydrocarbon chain determined by? —
The number of carbon atoms in the longest chain
46.
Consider the addition of water to 2-methylbut-2-ene under acidic conditions. The hydroxyl group is expected to add to which carbon atom based on regioselectivity? —
The internal carbon with two methyl groups (C2)
47.
What is the key difference between cis-2-butene and trans-2-butene? —
The methyl groups are on the same side of the double bond in cis-2-butene and on opposite sides in trans-2-butene.
48.
What is the primary goal of IUPAC nomenclature in organic chemistry? —
To ensure a unique and systematic name for every organic compound
49.
When a molecule contains a functional group with higher priority than an alkene or alkyne, the functional group determines the suffix, and the double or triple bond is treated as a substituent with its locant. —
True
50.
If a cycloalkane has a substituent, the carbon atom bearing the substituent is assigned position 1, and numbering proceeds in a direction that gives the next substituent(s) the lowest possible locant. —
True