-
How many \[\sigma \]and
\[\pi \] bonds are present in each of the following molecules?
(a)\[HC\equiv
CCH=CHC{{H}_{3}}\]
(b)\[{{H}_{2}}C=C=CHC{{H}_{3}}\]
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-
What is the type of
hybridisation of each carbon in the following compounds?
(a)\[C{{H}_{3}}Cl\] (b)
\[{{(C{{H}_{3}})}_{2}}CO\] (c) \[C{{H}_{3}}CN\] (d)
\[HCON{{H}_{2}}\]
(e) \[C{{H}_{3}}CH=CHCN\]
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-
Write the state of
hybridisation of carbon in the following compounds and shapes of each of the
molecules.
(a)\[{{H}_{2}}C=O\] (b)\[C{{H}_{3}}F\] (c)\[H-C\equiv
N\]
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-
Expand each of the following
condensed formulae into their complete structural formulae.
(a) \[C{{H}_{3}}C{{H}_{2}}COC{{H}_{2}}C{{H}_{3}}\]
(b) \[C{{H}_{3}}CH=CH{{(C{{H}_{2}})}_{3}}C{{H}_{3}}\]
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-
For each of the following
compounds, write condense formulae and also their bond line formulae.
(a)\[HOC{{H}_{2}}C{{H}_{2}}C{{H}_{2}}CH(C{{H}_{3}})CH(C{{H}_{3}})C{{H}_{3}}\]
(b) \[N\equiv C-\overset{\overset{\text{OH}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C\equiv N\]
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-
Expand each of the
following bond-line formulae to show all the atoms including carbon and
hydrogen.
(a)
(b)
(c)
(d)
-
Structures and IUPAC
names of some hydrocarbons are given ahead. Explain why the names given in the parentheses
are incorrect.
(a)
\[C{{H}_{3}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{CH}}\,-C{{H}_{2}}-C{{H}_{2}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{CH}}\,-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{2}}-C{{H}_{3}}\]
2, 5,
6-Trimethyloctane
(and not 3,
4, 7-Trimethyloctane)
(b) \[C{{H}_{3}}-C{{H}_{2}}-\underset{\underset{\text{C}{{\text{H}}_{\text{2}}}\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{CH}}\,-C{{H}_{2}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{2}}-C{{H}_{3}}\]
3-Ethyl-5-methylheptane
(and not
5-Ethyl-3-methyl heptane)
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-
Write the IUPAC
names of the compounds [(i)-(iv)] from their given structures.
(i) \[\overset{1}{\mathop{C{{H}_{3}}}}\,-\overset{2}{\mathop{C{{H}_{2}}}}\,-\underset{\underset{\text{OH}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{\overset{3}{\mathop{CH}}\,}}\,-\overset{4}{\mathop{C{{H}_{2}}}}\,-\overset{5}{\mathop{C{{H}_{2}}}}\,\]
\[-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{\overset{6}{\mathop{CH}}\,}}\,-\overset{7}{\mathop{C{{H}_{2}}}}\,-\overset{8}{\mathop{C{{H}_{3}}}}\,\]
(ii) \[\overset{6}{\mathop{C{{H}_{3}}}}\,-\overset{5}{\mathop{C{{H}_{2}}}}\,-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{
}}}\,}{\mathop{^{4}C}}\,-\overset{3}{\mathop{C{{H}_{2}}}}\,-{{\,}^{2}}\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-\overset{1}{\mathop{C{{H}_{3}}}}\,\]
(iii) \[\overset{6}{\mathop{C{{H}_{3}}}}\,-{{\,}^{5}}\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{
}}}\,}{\mathop{C}}\,-\overset{4}{\mathop{C{{H}_{2}}}}\,-\overset{3}{\mathop{C{{H}_{2}}}}\,-\overset{2}{\mathop{C{{H}_{2}}}}\,-\overset{1}{\mathop{COOH}}\,\]
(iv)\[\overset{6}{\mathop{HC}}\,\equiv
\overset{5}{\mathop{C}}\,-\overset{4}{\mathop{CH}}\,=\overset{3}{\mathop{CH}}\,-\overset{2}{\mathop{CH}}\,=\overset{1}{\mathop{C{{H}_{2}}}}\,\]
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-
Derive the structure
of
(i)
2-Chlorohexane,
(ii)
Pent-4-en-2-ol
(iii)
3-Nitrocyclohexene
(iv)
Cyclohex-2-en-l-ol
(v)
6-Hydroxyheptanal
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-
Write the structural
formula of :
(a) o-Ethylanisole
(b) p-Nitroaniline
(c) 2,
3-Dibromo-1-phenylpentane
(d) 4-Ethyl-1-fluoro-2-nitrobenzene
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-
Using curved arrow
notation, show the formation of reactive intermediates when the following
covalent bonds undergo heterolytic cleavage.
(a)\[C{{H}_{3}}-SC{{H}_{3}}\] (b)
\[C{{H}_{3}}-CN\]
(c)\[C{{H}_{3}}-Cu\]
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-
Giving justification,
categories the following molecules/ions as nucleophile or electrophile:
\[H{{S}^{-}},B{{F}_{3}},{{C}_{2}}{{H}_{5}}{{O}^{-}},{{(C{{H}_{3}})}_{3}}N_{\centerdot
}^{\centerdot };C{{l}^{+}},\]
\[C{{H}_{3}}-C=O,{{H}_{2}}N_{\centerdot }^{{{\centerdot
}^{-}}},\overset{+}{\mathop{N{{O}_{2}}}}\,\]
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-
Identify electrophilic centre in the following:
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-
Which bond is more
polar in the following molecules?
(a) \[{{H}_{3}}C-H,{{H}_{3}}C-Br\]
(b) \[{{H}_{3}}C-N{{H}_{2}},{{H}_{3}}C-OH\]
(c) \[{{H}_{3}}C-OH,{{H}_{3}}C-SH\]
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-
In which C-C bond of\[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}Br\],the
inductive effect is expected to be the least?
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-
Write resonance structures of \[C{{H}_{3}}CO{{O}^{-}}\]and
show the movement of electrons by curved arrows.
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-
Write the resonance structures of\[{{H}_{2}}C=CH-CHO.\]Indicate
relative stability of the contributing structures.
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-
Explain why the following two structures, I and II cannot be
the major contributors to the real structure of\[C{{H}_{3}}COOC{{H}_{3}}\].
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-
Explain why \[{{(C{{H}_{3}})}_{3}}{{C}^{+}}\] is more stable
than \[C{{H}_{3}}\overset{+}{\mathop{C{{H}_{2}}}}\,\] and \[\overset{+}{\mathop{C{{H}_{3}}}}\,\]
is the least stable cation.
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-
On complete combustion, 0.246 g of an organic compound gave
0.198 g of carbon dioxide and 0.1014 g of water. Determine the percentage
composition of carbon and hydrogen in the compound.
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-
In Duma's method of
estimation of nitrogen, 0.3 g of an organic compound gave 50 mL of nitrogen collected
at 300 K temperature and 715 mm pressure. Calculate the percentage composition
of nitrogen in the compound.
(Aqueous tension at 300 K = 15 mm).
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-
During estimation of nitrogen present in an organic compound
by Kjeldahls method, the ammonia evolved from 0.5 g of the compound in
Kjeldals estimation of nitrogen, neutralized 10 mL of 1 M\[{{H}_{2}}S{{O}_{4}}\].
Find out the percentage of nitrogen in the compound.
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-
In Carius method of estimation of halogen, 0.15 g of an organic
compound gave 0.12 g of\[AgBr\]. Find out the percentage of bromine in the
compound.
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-
In sulphur estimation, 0.157 g of an organic compound gave
0.4813 g of barium sulphate. What is the percentage of sulphur in the compound?
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-
What are hybridisation states
of each carbon atom in the following compounds?
(i) \[C{{H}_{2}}=C=O\] (ii)
\[C{{H}_{3}}CH=C{{H}_{2}}\]
(iii) \[{{(C{{H}_{3}})}_{2}}CO\] (iv)\[C{{H}_{2}}=CHCN\]
(v) \[{{C}_{6}}{{H}_{6}}\]
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-
Indicate the \[\sigma
\] and \[\pi \] -bonds in the following molecules:
(i) \[{{C}_{6}}{{H}_{6}}\]
(ii) \[{{C}_{6}}{{H}_{12}}\]
(iii) \[C{{H}_{2}}C{{l}_{2}}\]
(iv)\[{{H}_{2}}C=C=C{{H}_{2}}\]
(v) \[C{{H}_{3}}N{{O}_{2}}\]
(vi)\[HCONHC{{H}_{3}}\]
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-
Write bond line formulae for:
(i) Isopropylalcohol
(ii) 2,3-Dimethylbutanal
(iii) Heptan-4-one.
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-
Give the IUPAC names
of the following compounds:
(i)
(ii)
(iii)
(iv)
(v)
(vi) \[C{{l}_{2}}CHC{{H}_{2}}OH\]
-
Which of the
following represents the correct IUPAC name for the compounds concerned?
(i) 2,2-Dimethylpentane
or 2-Dimethylpentane
(ii) 2,4,7-Trimethyloctane
or 2,5,7-Trimethyloctane
(iii) 2-Chloro-4-methylpentane
or 4-Chloro-2-methylpentane
(iv) But-3-yn-1-ol
or But-4-ol-l-yne.
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-
Draw formulae for the first
five members of each homologous series beginning with the following compounds:
(i) \[HCOOH\] (ii) \[C{{H}_{3}}COC{{H}_{3}}\] (iii)
\[H-CH=C{{H}_{2}}\]
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-
Give condensed and
bond line structural formulae and identify the functional group(s) present, if
any, for:
(i) 2, 2, 4-Trimethylpentane
(ii)
2-Hydroxy-1, 2, 3-propanetricarboxylic acid
(iii) Hexanedial.
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-
Identify the
functional groups in the following compounds:
(i)
(ii)
(iii)
-
Which of the two: \[{{O}_{2}}NC{{H}_{2}}C{{H}_{2}}{{O}^{-}}\]
or \[C{{H}_{3}}C{{H}_{2}}{{O}^{-}}\] is expected to be more stable and why?
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-
Explain why alkyl groups act as electron donors when attached
to a \[\pi \]-system.
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-
Draw the resonance
structures for the following compounds. Show the electron shift using curved arrow
notation:
(i) \[{{C}_{6}}{{H}_{5}}OH\] (ii)
\[{{C}_{6}}{{H}_{5}}CHO\]
(iii) \[C{{H}_{3}}CH=CHCHO\] (iv)
\[{{C}_{6}}{{H}_{5}}CHO\]
(v) \[{{C}_{6}}{{H}_{5}}-\overset{+}{\mathop{C}}\,{{H}_{2}}\] (vi)\[C{{H}_{3}}CH=C{{H}^{+}}C{{H}_{2}}\]
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-
What are electrophiles and nucleophiles? Explain with examples.
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-
Identify the reagents shown in
bold in the following equations as nucleophiles or electrophiles:
(i) \[C{{H}_{3}}COOH+H{{O}^{-}}\xrightarrow{{}}C{{H}_{3}}CO{{O}^{-}}+{{H}_{2}}O\]
(ii) \[C{{H}_{3}}COCH+\mathbf{C}{{\mathbf{N}}^{\mathbf{-}}}\xrightarrow{{}}{{(C{{H}_{3}})}_{2}}C(CN)OH\]
(iii) \[{{C}_{6}}{{H}_{6}}+\mathbf{C}{{\mathbf{H}}_{\mathbf{3}}}\overset{\mathbf{+}}{\mathop{\mathbf{CO}}}\,\xrightarrow{{}}{{C}_{6}}{{H}_{5}}COC{{H}_{3}}\]
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-
Classify the
following reactions in one of the reaction type studied:
(i) \[C{{H}_{3}}C{{H}_{2}}Br+H{{S}^{-}}\xrightarrow{{}}C{{H}_{3}}C{{H}_{2}}SH\]
(ii)\[{{(C{{H}_{3}})}_{2}}C=C{{H}_{2}}+HCl\xrightarrow{{}}{{(C{{H}_{3}})}_{2}}CCl-C{{H}_{3}}\](iii)\[C{{H}_{3}}C{{H}_{2}}Br+H{{O}^{-}}\to
{{H}_{2}}C=C{{H}_{2}}+{{H}_{2}}O\]
(iv)\[{{(C{{H}_{3}})}_{3}}C-C{{H}_{2}}OH+HBr\to
(C{{H}_{3}})CBrC{{H}_{2}}C{{H}_{3}}\]
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-
What is the
relationship between the members of the following pairs of structures? Are they
structural orgeometrical isomers or resonance contributors?
(i)
(ii)
(iii)
-
For the following
bond cleavages, use curved arrows to show the electron flow and classify each
as homolysis orheterolysis. Identify reactive intermediate produced as free
radical, carbocation and carbanion.
(i) \[C{{H}_{3}}O-OC{{H}_{3}}\to
C{{H}_{3}}\overset{\centerdot }{\mathop{O}}\,+\overset{\centerdot
}{\mathop{O}}\,C{{H}_{3}}\]
(ii)
(iii)
(iv)
-
Explain the terms
inductive and electromeric effects.
Which
electron displacement effect explains the following correct order of acidity of
carboxylic acids?
(i) \[C{{l}_{3}}CCOOH>C{{l}_{2}}HCCOOH>ClC{{H}_{2}}COOH\](ii)
\[C{{H}_{3}}C{{H}_{2}}COOH>{{(C{{H}_{3}})}_{2}}CHCOOH\]\[>{{(C{{H}_{3}})}_{3}}CCOOH\]
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-
Explain the terms
inductive and electromeric effects.
Which
electron displacement effect explains the following correct order of acidity of
carboxylic acids?
(i) \[C{{l}_{3}}CCOOH>C{{l}_{2}}HCCOOH>ClC{{H}_{2}}COOH\](ii)
\[C{{H}_{3}}C{{H}_{2}}COOH>{{(C{{H}_{3}})}_{2}}CHCOOH\]\[>{{(C{{H}_{3}})}_{3}}CCOOH\]
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-
Give a brief
description of the principles of the following techniques taking an example in
each case:
(a) crystallisation
(b)
distillation
(c) chromatography
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-
Describe the method, which can be used to separate two compounds
with different solubilities in a solvent S.
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-
What is the difference between distillation, distillation under
reduced pressure and steam distillation?
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-
Discuss the chemistry of Lassaigne's test.
View Answer play_arrow
-
Differentiate between the principle of estimation of nitrogen
in an organic compound by: (i) Duma's method nd (ii) Kjeldanls method.
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-
Discuss the principle of estimation of halogens, sulphur and
phosphorus present in the organic compound.
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-
Explain the principle of paper chromatography.
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-
Why is nitric acid added to sodium extract before adding
silver nitrate for testing halogens?
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-
Explain the reason for the fusion of organic compound with
metallic sodium for testing nitrogen, sulphur and halogens.
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-
Name a suitable technique of separation of components from a
mixture of calcium sulphate and camphor.
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-
Explain why an organic liquid vaporises at a temperature
below its boiling point in its steam distillation?
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-
Will \[CC{{l}_{4}}\] give white ppt. of \[AgCl\] on heating
with silver nitrate? Give reason for your answer.
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-
Why a solution of potassium hydroxide used to absorb carbon
dioxide evolved during the estimation of carbon present in an organic compound?
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-
Why is it necessary to use acetic acid and not sulphuric acid
for acidification of sodium extract for testing sulphur by lead acetate test?
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-
An organic compound contains 69% carbon and 4.8% hydrogen,
the remainder being oxygen. Calculate the masses of carbon dioxide and water
produced when 0.20 g of this substance is subjected to complete combustion.
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-
A sample of 0.50 g of an organic compound was treated
according to Kjeldahls method. The ammonia evolved was absorbed in 50 mL of
0.5 M\[{{H}_{2}}S{{O}_{4}}\]. The residual acid required 60 mL of 0.5 M
solution of\[NaOH\] for neutralisation. Find the percentage composition of
nitrogen in the compound.
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-
0.3780 g of an organic chloro compound gave 0.5740 g of
silver chloride in Carius estimation. Calculate the percentage of chlorine
present in the compound.
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-
In the estimation of sulphur by Carius method, 0.468 g of an
organic sulphur compound afforded 0.668 g of barium sulphate. Find out the
percentage of sulphur in the given compound.
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-
In the
organic compound
\[{{H}_{2}}C=CHC{{H}_{2}}C{{H}_{2}}C=CH\],
the pair of hybridised orbitals involved in the formation of\[{{C}_{2}}-{{C}_{3}}\]
bond is:
(a) \[sp-s{{p}^{2}}\] (b)
\[sp-s{{p}^{3}}\]
(c)\[s{{p}^{2}}-s{{p}^{3}}\] (d)\[~s{{p}^{3}}-s{{p}^{3}}\]
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In the Lassaigne's
test for nitrogen in an organic compound, the prussian blue colour is obtained
due to the formation of:
(a) \[N{{a}_{4}}[Fe{{(CN)}_{6}}]\] (b)
\[F{{e}_{4}}{{[Fe{{(CN)}_{6}}]}_{3}}\]
(c) \[F{{e}_{2}}[Fe{{(CN)}_{6}}]\] (d)
\[F{{e}_{3}}{{[Fe{{(CN)}_{6}}]}_{6}}\]
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Which of the
following carbocation is most stable?
(a) \[{{(C{{H}_{3}})}_{3}}\overset{+}{\mathop{CC{{H}_{2}}}}\,\] (b)
\[{{(C{{H}_{3}})}_{3}}{{C}^{+}}\] (c) \[C{{H}_{3}}C{{H}_{2}}\overset{+}{\mathop{C{{H}_{2}}}}\,\] (d)
\[C{{H}_{3}}\overset{+}{\mathop{C}}\,HC{{H}_{2}}C{{H}_{3}}\]
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The best and latest technique
for isolation, purification and separation of organic compound is:
(a) crystallization (b) distillation (c)
sublimation (d)chromatography
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The reaction:
\[C{{H}_{3}}C{{H}_{2}}I+KOH(aq.)\to
C{{H}_{3}}C{{H}_{2}}OH+KI\]is classified as:
(a) electrophilic
substitution (b) nucleophilic
substitution
(c) elimination (d)
addition
View Answer play_arrow
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question_answer66)
Which of the following is the correct
IUPAC name?
(a) 3-Ethyl-4, 4-dimethylheptane (b)
4, 4-Dimethyl-3-ethylheptane
(c) 5-Ethyl-4, 4-dimethylheptane (d)
4, 4-Bis (methyl)-3-ethylheptane
View Answer play_arrow
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question_answer67)
The IUPAC name for \[C{{H}_{3}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{
}}}\,}{\mathop{C}}\,-C{{H}_{2}}-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-OH\]is :
(a) 1-hydroxypentane-1, 4-dione (b)
1, 4-dioxopentanol
(c) 1-carboxybutan-3-one (d)
4-oxopentanoic acid
View Answer play_arrow
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question_answer68)
The IUPAC name for :
(a) 1-chloro-2-nitro-4-methylbenzene (b)
1-chloro-4-methyl-2-nitrobenzene
(c) 2-chloro-1-nitro-5-methylbenzene (d)
m-nitro-p-chlorotoluene
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question_answer69)
Electro negativity of carbon
atoms depends upon their state of hybridisation. In which of the following
compounds, the cabron marked with asterisk is most electronegative?
(a) \[C{{H}_{3}}-C{{H}_{2}}-{{\,}^{*}}C{{H}_{2}}-C{{H}_{3}}\] (b)
\[C{{H}_{3}}-{{\,}^{*}}CH=CH-C{{H}_{3}}\]
(c) \[C{{H}_{3}}-C{{H}_{2}}-C\equiv
{{\,}^{*}}CH\] (d) \[C{{H}_{3}}-C{{H}_{2}}-CH={{\,}^{*}}C{{H}_{2}}\]
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question_answer70)
In which of the following,
functional groups isomerism is not possible?
(a) Alcohols (b)
Aldehydes (c) Alkyl halides (d) Cyanides
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question_answer71)
The fragrance of flowers is due
to the presence of some steam volatile organic compounds called essential oils.
These are generally insoluble in water at room temperature but are miscible
with water vapour in vapour phase. A suitable method for the extraction of
these oils from the flowers is :
(a) distillation (b)
crystallisation
(c) distillation under reduced
pressure (d) steam distillation
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question_answer72)
During hearing of a court case,
the judge suspected that some changes in the documents had been carried out. He
asked the forensic department to check the ink used at two different places.
According to you which technique can give the best results?
(a) Column chromatography (b)
Solvent extraction
(c) Distillation (d)
Thin layer chromatography
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question_answer73)
The principle involved in paper
chromatography is :
(a) adsorption (b)
partition (c) solubility (d)
volatility
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question_answer74)
What is the correct order of
decreasing stability of the following cations?
\[C{{H}_{3}}-\underset{(I)}{\mathop{\overset{\oplus
}{\mathop{CH}}\,}}\,-C{{H}_{3}}\] \[C{{H}_{3}}-\underset{\text{(II)}}{\mathop{\overset{\oplus
}{\mathop{CH}}\,}}\,-OC{{H}_{3}}\] \[C{{H}_{3}}-\overset{\oplus
}{\mathop{CH}}\,-\underset{(III)}{\mathop{C{{H}_{2}}}}\,-OC{{H}_{3}}\]
(a) II > I >
III (b) II > III > I (c)
III > I > II (d) I > II > III
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question_answer75)
Correct IUPAC name for
\[{{H}_{3}}C-\underset{\underset{{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\mathop{CH}}\,-\underset{\underset{{{\text{C}}_{\text{2}}}{{\text{H}}_{\text{5}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{3}}\]is:
(a) 2-ethyl-3-methylpentane (b)
3, 4-dimethylhexane
(c) 2-sec-butylbutane (d)
2, 3-dimethylbutane
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question_answer76)
In which of the following
compounds the carbon marked with asterisk is expected to have greatest positive
charge?
(a) \[{{\,}^{*}}C{{H}_{3}}-C{{H}_{2}}-Cl\] (b)
\[{{\,}^{*}}C{{H}_{3}}-C{{H}_{2}}-M{{g}^{+}}C{{l}^{-}}\]
(c) \[{{\,}^{*}}C{{H}_{3}}-C{{H}_{2}}-Br\] (d)
\[{{\,}^{*}}C{{H}_{3}}-C{{H}_{2}}-C{{H}_{3}}\]
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question_answer77)
Ionic species are stabilised by
the dispersal of charge. Which of the following carboxylate ions is the most
stable?
(a) \[C{{H}_{3}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-{{O}^{-}}\] (b) \[Cl-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-{{O}^{-}}\] (c)
\[F-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{ }\!\!|\!\!\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-{{O}^{-}}\] (d) 
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question_answer78)
Electrophilic addition reactions
proceed in two steps. The first step involves the addition of an electrophile.
Name the type of intermediate formed in the first step of the following addition
reaction :
\[{{H}_{3}}C-HC=C{{H}_{2}}+{{H}^{+}}\to
?\]
(a) \[2{}^\circ \text{
}Carbanion~~~~~~~~~\] (b)\[~1{}^\circ \text{ }Carbocation\] (c)\[~2{}^\circ
\text{ }Carbocation\] (d) \[1{}^\circ \text{ }Carbanion\]
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question_answer79)
Covalent bond can undergo
fission in two different ways. The correct representation involving a
heterolytic fission of \[C{{H}_{3}}Br\]is:
(a) 
(b)
(c) 
(d)
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question_answer80)
The addition of \[HCl\] to an
alkene proceeds in two steps. The first step is the attack of \[{{H}^{+}}\]ion
to 
portion which
can be shown as:
(a) 
(b)
(c) 
(d)
all of these are possible
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question_answer81)
Which of the following compounds
contain all the carbon atoms in the same hybridisation state?
(a)\[~H-C=C-C=C-H\] (b)
\[C{{H}_{3}}-C\equiv C-C{{H}_{3}}\]
(c)\[C{{H}_{2}}=C=C{{H}_{2}}\] (d)
\[C{{H}_{2}}=C=C{{H}_{2}}\]
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question_answer82)
In which of the following
representations given below spatial arrangement of group/atom different from
that given in structure 'A'?
(a) 
(b)
(c) 
(d) 
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question_answer83)
Electrophiles are electron seeking
species. Which of the following groups contain only electrophiles?
(a) \[B{{F}_{3}},N{{H}_{3}},{{H}_{2}}O\] (b)\[AlC{{l}_{3}},S{{O}_{2}},NO_{2}^{+}\]
(c) \[NO_{2}^{+},CH_{3}^{+},C{{H}_{3}}-\overset{+}{\mathop{C}}\,=O\] (d)
\[{{C}_{2}}H_{5}^{-},{{\overset{\centerdot
}{\mathop{C}}\,}_{2}}{{H}_{5}},{{C}_{2}}H_{5}^{+}\]
Note: Consider the following
four compounds for answering questions 19 and 20:
\[\text{I}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-H\]
\[\text{II}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-C{{H}_{3}}\]
\[\text{III}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-\underset{\underset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-C{{H}_{2}}-C{{H}_{3}}\]
\[\text{IV}\text{.}\]\[C{{H}_{3}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{2}}-\underset{\underset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-H\]
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question_answer84)
Which of the following pairs are
position isomers?
(a) I and II (b)
II and III (c) II and IV (d)
III and IV
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question_answer85)
Which of the following pairs are
not functional group isomers?
(a) II and III (b)
II and IV (c) I and IV (d) I
and II
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question_answer86)
Nucleophile is a species that
should have :
(a) a pair of electrons to
donate (b) positive charge
(c) negative charge (d)
electron deficient species
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question_answer87)
Hyper conjugation involves delocalization
of :
(a) electrons of carbon-hydrogen
o bond of an alkyl group directly attached to an atom of unsaturated system
(b) electrons of carbon-hydrogen
o bond of alkyl group directly attached to the positively charged carbon atom
(c) \[\pi \]-electrons of
carbon-carbon bond
(d) lone pair of electrons
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question_answer88)
Note : Consider structures I
to VII and answer the questions 23-26.
\[I.\]\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-OH\]
\[\text{II}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-\underset{\underset{\text{OH}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{3}}\]
\[\text{III}\text{.}\]\[C{{H}_{3}}-\underset{\underset{\text{OH}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\overset{\overset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{C}}}\,-C{{H}_{3}}\]
\[\text{IV}\text{.}\]\[C{{H}_{3}}-\underset{\begin{smallmatrix}
| \\
C{{H}_{3}}
\end{smallmatrix}}{\mathop{C}}\,H-C{{H}_{2}}-OH\]
\[\text{V}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-O-C{{H}_{2}}-C{{H}_{3}}\]
\[\text{VI}\text{.}\]\[C{{H}_{3}}-O-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{3}}\]
\[\text{VII}\text{.}\]\[C{{H}_{3}}-O-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{3}}\]
Which of the above compounds form pairs
of metamers?
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question_answer89)
Identify the pairs of compounds
which are functional group isomers.
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question_answer90)
Identify the pairs of compounds
that represent position isomerism.
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question_answer91)
Identify the pairs of compounds
that represent chain isomerism.
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question_answer92)
For testing halogens in an
organic compound with \[AgN{{O}_{3}}\]solution, sodium extract (Lassaigne's
test) is acidified with dilute\[HN{{O}_{3}}\]. What will happen if a student
acidifies the extract with dilute \[{{H}_{2}}S{{O}_{4}}\] in place of dilute\[HN{{O}_{3}}\]?
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question_answer93)
What is the hybridisation of
each carbon in \[{{H}_{2}}C=C=C{{H}_{2}}?\]
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question_answer94)
Explain, how is the electro negativity
of carbon atoms related to their state of hybridisation in an organic compound?
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question_answer95)
Show the polarisation of
carbon-magnesium bond in the following structure :
\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-Mg-X.\]
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question_answer96)
Compounds with same molecular
formula but differing in their structures are said to be structural isomers.
What type of structural isomerism is shown by :
\[C{{H}_{3}}-S-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{3}}\]
and 
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question_answer97)
Which of the following selected
chains is correct to name the given compound according to IUPAC system?
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question_answer98)
In DNA and RNA, nitrogen atom is
present in the ring system. Can Kjeldahl method be used for the estimation of nitrogen
present in these? Give reasons.
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question_answer99)
If a liquid compound decomposes
at its boiling point, which method(s) can you choose for its purification. It
is known that the compound is stable at low pressure, steam volatile and
insoluble in water.
Note: Answer the questions 35
to 38 on the basis of information given below:
"Stability of
carbocations depends upon the electron releasing inductive effect of groups
adjacent to positively charged carbon atom involvement of neighbouring groups
in hyper conjugation and resonance."
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question_answer100)
Draw the possible resonance
structures for \[C{{H}_{3}}-\underset{\centerdot \centerdot
}{\overset{\centerdot \centerdot }{\mathop{O}}}\,-\overset{+}{\mathop{C{{H}_{2}}}}\,\]
and predict which of the structures is more stable. Give reason for your
answer.
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question_answer101)
Which of the following ions is more
stable? Use resonance to explain your answer.
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question_answer102)
The structure of triphenylmethyl cation
is given below. This is very stable and some of its salts can be stored for
months. Explain the cause of high stability of this cation.
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question_answer103)
Write structures of various carbocations
that can be obtained from 2-methylbutane. Arrange these carbocations in order
of increasing stability.
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question_answer104)
Three students, Manish, Ramesh
and Rajni were determining the extra elements present in an organic compound
given by their teacher. They prepared the Lassaigne's extract (L.E.)
independently by the fusion of the compound with sodium metal. Then they added
solidFeS04 and dilute sulphuric acid to a part of Lassaigne's extract. Manish
and Rajni obtained prussian blue colour but Ramesh got red colour. Ramesh
repeated the test with the same Lassaigne's extract, but again got red colour only.
They were surprised and went to their teacher and told him about their
observation. Teacher asked them to think over the reason for this. Can you help
them by giving the reason for this observation? Also, write the chemical equations
to explain the formation of compounds of different colours.
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question_answer105)
Name the compounds whose line
formulae are given below:
(i) 
(ii)
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question_answer106)
Write structural formulae for
compounds named as :
(a) 1-Bromoheptane
(b) 5-Bromoheptanoic acid
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question_answer107)
Draw the resonance structures of
the following compounds:
(i) \[C{{H}_{2}}=CH-\underset{\centerdot
\centerdot }{\overset{\centerdot \centerdot }{\mathop{Cl_{\centerdot
}^{\centerdot }}}}\,\]
(ii) \[C{{H}_{2}}=CH-CH=C{{H}_{2}}\]
(iii) \[C{{H}_{2}}=CH-\underset{\underset{\text{H}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,=O\]
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question_answer108)
Identify the most stable species
in the following sets of ions giving reasons :
(i) \[\overset{+}{\mathop{C{{H}_{3}}}}\,,\overset{+}{\mathop{C{{H}_{2}}Br}}\,,\overset{+}{\mathop{CHB{{r}_{2}}}}\,,\overset{+}{\mathop{CB{{r}_{3}}}}\,\]
(ii) \[\overset{O-}{\mathop{C{{H}_{3}}}}\,,\overset{O-}{\mathop{C{{H}_{2}}Cl}}\,,\overset{O-}{\mathop{CHC{{l}_{2}}}}\,,\overset{O-}{\mathop{CC{{l}_{3}}}}\,\]
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question_answer109)
Give three points of differences
between inductive effect and resonance effect.
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question_answer110)
Which of the following compounds
will not exist as resonance hybrid? Give reason for your answer :
(i) \[C{{H}_{3}}OH\] (ii)
\[R-CON{{H}_{2}}\] (iii) \[C{{H}_{3}}CH=CHC{{H}_{2}}N{{H}_{2}}\]
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question_answer111)
Why does \[S{{O}_{3}}\] act as
an electrophile?
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question_answer112)
Resonance structures of propenal
are given below. Which of these resonating structures is more stable? Give
reason for your answer.
\[C{{H}_{2}}=\underset{I}{\mathop{CH}}\,-CH=O\overset{{}}{\longleftrightarrow}\overset{O-}{\mathop{C{{H}_{2}}}}\,-\underset{II}{\mathop{CH}}\,=CH-\overset{O-}{\mathop{O}}\,\]
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question_answer113)
By mistake, an alcohol (boiling
point\[97{}^\circ C\]) was mixed with a hydrocarbon (boiling point\[68{}^\circ
C\]). Suggest a suitable method to separate the two compounds. Explain the
reason for your choice.
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question_answer114)
Which of the two structures (A)
and (B) given below is more stabilised by resonance? Explain.
\[\underset{(A)}{\mathop{C{{H}_{3}}COOH}}\,\] and \[\underset{(B)}{\mathop{C{{H}_{3}}CO\overset{O-}{\mathop{O}}\,}}\,\]
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question_answer115)
In the following questions
more than one correlation is possible between options of column I and column
II. Make as many correlations as you can.
Match the type of mixture of
compounds in Column I with the technique of separation/purification given in
Column II.
|
Column I
|
Column II
|
|
(i) Two solids which have different
solubilities in a solvent and which do not undergo reaction when dissolved in
it.
|
(a) Steam distillation
|
|
(ii) Liquid that decomposes at its
boiling point
|
(b) Fractional distillation
|
|
(iii) Steam volatile liquid
|
(c) Simple distillation
|
|
(iv) Two liquids which have boiling
points close to each other
|
(d) Distillation under Reduced
pressure
|
|
(v) Two liquids with large difference
in boiling points.
|
(e) Crystallisation
|
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question_answer116)
Match the terms mentioned in Column I
with the terms in Column II.
|
Column I
|
Column II
|
|
(i)
Carbocation
|
(a)
Cyclohexane and 1-hexene
|
|
(ii)
Nucleophile
|
(b)
Conjugation of electrons of C?H \[\sigma \] bond with empty p-orbital present
at adjacent positively charged carbon.
|
|
(iii)
Hyper conjugation
|
(c)
\[s{{p}^{2}}\]-hybridised carbon with empty p-orbital
|
|
(iv)
Isomers
|
(d)
Ethyne
|
|
(v)
\[sp\]-hybridisation
|
(e)
Species that can receive a pair of electrons
|
|
(vi)
Electrophile
|
(f)
Species that can supply a pair of electrons
|
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question_answer117)
Match Column I with Column II.
|
Column I
|
Column II
|
|
(i) Duma's method
|
(a)
|
|
(ii) Kjeldahl?s method
|
(b) Silica gel
|
|
(iii) Carius method
|
(c) Nitrogen gas
|
|
(iv) Chromatography
|
(d) Free radicals
|
|
(v) Homolysis
|
(e) Ammonium sulphate
|
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question_answer118)
Match the intermediates given in Column
I with their probable structure in Column II.
|
Column I
|
Column II.
|
|
(i) Free radical
|
(a) Trigonal planar
|
|
(ii) Carbocation
|
(b) Pyramidal
|
|
(iii) Carbanion
|
(c) Linear
|
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question_answer119)
Match the ions given in Column I
with their nature given in Column II.
|
Column I
|
Column II
|
|
(i) \[C{{H}_{3}}-\underset{\centerdot
\centerdot }{\overset{\centerdot \centerdot }{\mathop{O}}}\,-\overset{\oplus
}{\mathop{CH}}\,-C{{H}_{3}}\]
|
(a) Stable due to resonance
|
|
(ii) \[{{F}_{3}}-{{C}^{\oplus }}\]
|
(b) Destabilised due to inductive
effect
|
|
(iii) \[C{{H}_{3}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{
}}}\,}{\overset{\overset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{{{C}^{O-}}}}}\,\]
|
(c) Stabilised by hyper conjugation
|
|
(iv) \[C{{H}_{3}}-\overset{\oplus
}{\mathop{C}}\,H-C{{H}_{3}}\]
|
(d) A secondary carbocation
|
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question_answer120)
In the following questions a
statement of Assertion (A) followed by a statement of Reason (R) is given.
Choose the correct option out of the choices given below:
(a) If both A and R
are correct and R is the correct explanation of the A.
(b) If both A and R
are correct but R is not the correct explanation of the A.
(c) If both A and R are not
correct.
(d) If A is incorrect but R is
correct.
(A) Simple distillation
can help in separating a mixture of propan-1-ol (boiling point\[97{{\,}^{{}^\circ
}}C\]) and propanone (boiling point\[56{}^\circ C\]).
(R) Liquids with a
difference of more than \[20{}^\circ C\]in their boiling points can be
separated by simple distillation.
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question_answer121)
(A) Energy of resonance
hybrid is equal to the average of energies of all canonical forms.
(R) Resonance hybrid
cannot be presented by a single structure.
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question_answer122)
(A) Pent-1-ene and
pent-2-ene are position isomers.
(R) Position isomers
differ in the position of functional group or a substituent.
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question_answer123)
(A) All the carbon atoms
in \[{{H}_{2}}C=C=C{{H}_{2}}\] are\[s{{p}^{2}}\] -hybridised.
(R) In this molecule all
the carbon atoms are attached to each other by double bonds.
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question_answer124)
(A) Sulphur present in an
organic compound can be estimated quantitatively by Duma's method.
(R) Sulphur is separated
easily from other atoms in the molecule and gets precipitated as light yellow
solid.
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question_answer125)
(A) Components of a
mixture of red and blue inks can be separated by distributing the components
between stationary and mobile phases in paper chromatography.
(R) The, coloured
components of inks migrate at differentrates because paper selectively retains
different components according to the difference in their partition between the
two phases.
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question_answer126)
What is meant by hybridisation?
Compound \[C{{H}_{2}}=C=C{{H}_{2}}\] contains \[sp\]or \[s{{p}^{2}}\]hybridised
carbon atoms. Will it be a planar molecule?
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question_answer127)
Benzoic acid is a organic
compound. Its crude sample can be purified by crystallisation from hot water.
What characteristic differences in the properties of benzoic acid and the
impurity make this process of purification suitable?
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question_answer128)
Two liquids (A) and (B) can be
separated by the method of fractional distillation. The boiling point of liquid
(A) is less than boiling point of liquid (5). Which of the liquids do you
expect to come out first in the distillate? Explain.
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question_answer129)
You have a mixture of three
liquids A, B and C. There is a large difference in the boiling points of A and
rest of the two liquids, i.e., B and C. Boiling point of liquids B and Care
quite close. Liquid A boils at a higher temperature than B and C and boiling
point of B is lower than C. How will you separate the components of the
mixture? Draw a diagram showing set up of the apparatus for the process.
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question_answer130)
Draw a diagram of bubble plate
type fractionating column. When do we require such type of a column for
separating two liquids? Explain the principle involved in the separation of
components of a mixture of liquids by using fractionating column. What
industrial applications does this process have?
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question_answer131)
A liquid with high boiling point
decomposes on simple distillation but it can be steam distilled for its
purification. Explain how is it possible?
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