This set of Organic Chemistry Multiple Choice Questions & Answers (MCQs) focuses on “Nomenclature”.
1. Saturated hydrocarbons are otherwise referred as
Explanation: Saturated hydrocarbons contain large number of hydrogen atoms in them and hence they are known as alkanes.
2. Identify the correct alkane name for the molecular formula C30H62
Explanation: Triacontane is the alkane with the molecular formula C30H62 as alkanes have the general formula CnH2n+2.
3. Identify the smallest alkane which can form a ring structure (cycloalkane)
Explanation: Cyclopropane is the only smallest alkane that can form a successful ring structure with C-C bond on removal of a hydrogen atom.
4. In which among the following alkane, a carbon atom is displaced so as to form a compactly structure with the resemblance of a butterfly wing
Explanation: If one of the carbon atoms of cyclobutane is not displaced, then the C-C bond would be exactly at right angles to each other and they do not form a cyclic structure.
5. The first step in IUPAC nomenclature is to identify the total number of carbon atoms present in the compound. State true or false
Explanation: The first step is to find the number of carbon atoms present only in the main/ longest chain of the compound.
6. The substituent in the chain is named by replacing the “ane” in the alkanes by
Explanation: ene, ic and one are used for representing alkenes, carboxylic acids, and ketones respectively, hence yl is the term which is to be substituted in place on ane in the alkanes.
7. The C=C bond in the chain of the compound considered is shown by
a) Specifying the number of carbon atoms associated with the bond
b) Specifying the number of carbon atoms at beginning of the C=C bond
c) Specifying the number of carbon atoms at end of the C=C bond
d) Specifying the number of carbon atoms in the entire chain
Explanation: According to the rules of IUPAC, The C=C bond in the chain of the compound considered is shown by specifying the number of carbon atoms at beginning of the C=C bond.
8. Dienes are the name given to compounds with
a) Exactly a double bond
b) Exactly a triple bond
c) Exactly two double bond
d) more than two double bond
Explanation: Alkenes are the name given to compound with one double bond and dienes are the one given to compounds with two double bond.
9. Triple bond with two carbon atoms on either side is called
a) Methnyl group
b) Ethynyl group
c) Propionyl group
d) Propargyl group
Explanation: Triple bond with two atoms on either side are called as ethynyl group and those with one carbon on one side and two carbon on another side are called as propargyl group.
10. The substituent groups that are commonly associated with benzene ring are
a) Phenyl and benzyl
b) Propyl and phenyl
c) Methyl and benzyl
d) Butyl and phenyl
Explanation: Phenyl and benzyl are commonly associated with benzene ring due to their closely associated structure with difference in hydrogen atom.
Sanfoundry Global Education & Learning Series – Organic Chemistry.
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