General Organic Chemistry MCQ Questions & Answers in Organic Chemistry | Chemistry
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131.
Which method can be applied to separate a mixture of camphor and benzoic acid?
A
Sublimation
B
Chemical methods
C
Crystallisation
D
Extraction with solvent
Answer :
Chemical methods
No explanation is given for this question. Let's discuss the answer together.
132. obtained by
chlorination of $$n-butane,$$ will be
A
$$meso$$ form
B
racemic mixture
C
$$d$$ - form
D
$$l$$ - form
Answer :
racemic mixture
Chlorination of $$n-butane$$ takes place by free radical mechanism as follows :
133.
The IUPAC name of the compound $$C{H_2} = CH - CH{\left( {C{H_3}} \right)_2}\,{\text{is}}$$
A
1, 1 - dimethyl - 2 - propene
B
3 - methyl 1- butene
C
2 - vinylpropane
D
1 - isopropylethylene
Answer :
3 - methyl 1- butene
134.
The IUPAC name of the following compound is
A
4 - Bromo - 3 - cyanophenol
B
2 - Bromo - 5 - hydroxybenzonitrile
C
2 - Cyano - 4 - hydroxybromobenzene
D
6 - Bromo - 3 - hydroxybenzonitrile
Answer :
2 - Bromo - 5 - hydroxybenzonitrile
$$ - CN$$ has highest priority. Further the sum of locants is 7 in (b) and 9 in (d).
135.
Few pairs of molecules are given below. Which pair has more polar molecules?
A
$${H_3}C - H,{H_3}C - Br$$
B
$${H_3}C - N{H_2},{H_3}C - OH$$
C
$${H_3}C - OH,{H_3}C - SH$$
D
$${H_3}C - Cl,{H_3}C - Br$$
Answer :
$${H_3}C - N{H_2},{H_3}C - OH$$
Highly electronegative atom makes the bond more polar.
136.
The IUPAC name of the compound is
A
3, 3 - dimethyl - 1 - cyclohexanol
B
1, 1- dimethyl - 3 - hydroxy cyclohexane
C
3,3 - dimethyl - 1 - hydroxy cyclohexane
D
1, 1 - dimethyl - 3 - cyclohexanol
Answer :
3, 3 - dimethyl - 1 - cyclohexanol
IUPAC name - 3, 3 - Dimethyl -1 cyclohexanol
137.
The order of stability of the following carbocations :
A
III > II > I
B
II > III > I
C
I > II > III
D
III > I > II
Answer :
III > I > II
Higher stability of allyl and aryl substituted methyl carbocation is due to dispersal of positive charge due to resonance
whereas in alkyl carbocations dispersal of positive charge on different hydrogen atoms is due to hyper conjugation hence the correct order of stability will be
138.
The most stable canonical structure among the given structure is :
A
I
B
II
C
III
D
all are equally stable
Answer :
III
It has complete octet for all atoms.
139.
$$0.46\,g$$ of an organic compound was analysed. The increase in mass of $$CaC{l_2}$$ $$U$$ - tube was $$0.54\,g$$ and potash bulb was $$0.88\,g.$$ The percentage composition of the compound is