Nomenclature Of Organic Compounds(12th Grade > Chemistry ) Questions and Answers
Explanation:-
Answer: Option B. -> 5, 5-Bis(1,1-dimethylpropyl)-2-methyldecane:
B
Decide the parent chain and give the numbering so that more substituted substituent will get the least number.
![Click to Enlarge Image The IUPAC Name Of The Following Compound Is?](https://lakshyaeducation.in/quizpics/quiz/68279_49b58282d2a5870e64dcedc421167059f68d34a820160609-1952-lqnlr0.png)
parent chain
10 carbons ⇒ word root ⇒ dec
single bond ⇒ suffix ⇒ ane
substituents at C5andC2
Now,
![Click to Enlarge Image The IUPAC Name Of The Following Compound Is?](https://lakshyaeducation.in/quizpics/quiz/68279_5b7a245682fe7cbb4262d47316cdac43c436315220160609-1952-1ekhk9.png)
There is one more same substituent on C5
Therefore,
5,5-Bis-(1,1-dimethyl propyl)
Bis⇒ Because two same substituents are there, and a methyl group at C2⇒ 2-methyl
Therefore,
5,5-Bis-(1,1-dimethylpropyl)-2-methyldecane
Explanation:-
Answer: Option B. -> Pent-1-en-4-yne:
B
While naming, the double bond gets a lower number than the triple bond.
C1H2=C2H−C3H2−C4≡C5H
Wort root = pent
Pent-1-en-4-yne
Not 4-Penten-1-yne
Because, if there is a choice in numbering, the double bond is always given preferenceover the triplebond.
Explanation:-
Answer: Option C. -> 1-Ethyl-2-Methylcyclohexane:
C
The numbering is according to the lowest of locants, which gives us two options.
![Click to Enlarge Image The IUPAC Name Of The Following Compound Is](https://lakshyaeducation.in/quizpics/quiz/68353_41c1c7c453a7a59ec6b9bff3c005c47685a21a1020160609-12440-1qaap6p.png)
In this case, numbering happens according to alphabetical order. So ethyl group will have thelower number.
![Click to Enlarge Image The IUPAC Name Of The Following Compound Is](https://lakshyaeducation.in/quizpics/quiz/68353_18d32720cf22e7a46cfe4113c47e73303f1694d220160609-12440-1pulwrb.png)
word root = hex
primary prefix = cyclo
secondary prefix = 1-Ethyl-2-methyl
primary suffix = ane
IUPAC name is
(c)1-Ethyl-2-methylcyclohexane
Explanation:-
Answer: Option B. -> 3-Ethyl-2,3-dimethylpentane:
B
Decide parent chain.
Numbering so that more substitutedsubstituent will get the lowest number.
![Click to Enlarge Image The IUPAC Name Of The Following Compound Is?](https://lakshyaeducation.in/quizpics/quiz/68214_b481b857f3552aaf5c467ad7ac19bba9211fd74820160609-12416-71vy8c.png)
Five carbons ⇒ word root = pent
single bonds = ane(suffix)
→ substituent at C2andC3
⇒ 3-ethyl-2, 3-dimethylpentane(alphabetically)
Therefore,
(b)3-Ethyl-2,3-dimethylpentane
Explanation:-
Answer: Option D. -> 2-Chloro-2-methylpropane:
D
The given compound tertiary butyl chloride is
![Click to Enlarge Image The Systematic (IUPAC) Name Of Tertiary Butyl Chloride Is:](https://lakshyaeducation.in/quizpics/quiz/68331_20ee24fa58677cb5d26df14988bf7d5ff5e096be20160609-1956-vst5xc.png)
It is numbered as shown.
The longest chain clearly includes 3 carbon atoms
⇒ root word = prop
primary suffix = ane
Secondary prefix = 2-chloro-2-methyl
Hence the name (systematic IUPAC) of given compound is:
(d)2-Chloro-2-methylpropane
Explanation:-
Answer: Option A. -> 6-Ethyl-3,3-dimethylcyclohex-1-ene:
A
In this compound, the parent chain is the one containing cycliccarbon.
Now, we number in the following way.
![Click to Enlarge Image The IUPAC Name Of](https://lakshyaeducation.in/quizpics/quiz/68254_a99419b0da0939b94afa5d44b23e3acf0ffe963920160610-15346-kz6v7w.png)
Because more substituted will get the lower number.
→ethyl group at C5
→Two methyl group at C3
Therefore, it will be
6-Ethyl-3-3-Dimethylcyclohex-1-ene
not
3,3-Dimethyl-6-ethylcyclohex-1-ene
Because we use alphabetical order and Di- is not considered for the alphabetical order.
Explanation:-
Answer: Option A. -> 3-(Formylmethyl)hexanal:
A
The given compound is:
![Click to Enlarge Image The IUPAC Name Of](https://lakshyaeducation.in/quizpics/quiz/68212_a4c589b9a49c82b1150b8c7157cdf45d32a0cedf20160610-30521-pvrhx3.png)
Here we include as many -CHO groups as possible in the longest chain.Thus it is numbered as above (to give lowest possible number to the substituents -CH2−CHO).This group is namedformylmethyl.
6 carbons = hex.
Since there are no carbon - carbon multiple bonds, primary suffix = ane; secondary suffix = dial.
Hence the IUPAC name is
(a) 3 -(Formylmethyl)hexanal
Note the parentheses indicating substituted substituent.
The compound could also be named 3-propylpentanedial
Explanation:-
Answer: Option A. -> 3-Ethyl-4,4-dimethylheptane:
A
First, check the parent chain.
Now, give numbers such that the more substituted substituent will get the lowest number.
![Click to Enlarge Image The IUPAC Name Of This Compound Is?](https://lakshyaeducation.in/quizpics/quiz/68227_01467900aa7016566769c465281f5a23267ecc0920160609-12440-7j5peu.png)
Parent chain
7 carbon ⇒ hept (word root)
Single bonds ⇒ ane (suffix
→ substituent at C3andC4 3-ethyl-4,4-dimethyl(alphabetically)
Therefore, 3-Ethyl-4,4-dimethylheptane