-
How many \[\sigma \]and
\[\pi \] bonds are present in each of the following molecules?
(a)\[HC\equiv
CCH=CHC{{H}_{3}}\]
(b)\[{{H}_{2}}C=C=CHC{{H}_{3}}\]
View Answer play_arrow
-
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) \[C{{H}_{3}}CH=CHCN\]
View Answer play_arrow
-
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)\[H-C\equiv
N\]
View Answer play_arrow
-
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) \[C{{H}_{3}}CH=CH{{(C{{H}_{2}})}_{3}}C{{H}_{3}}\]
View Answer play_arrow
-
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) \[N\equiv C-\overset{\overset{\text{OH}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C\equiv N\]
View Answer play_arrow
-
Expand each of the
following bond-line formulae to show all the atoms including carbon and
hydrogen.
(a)
(b)
(c)
(d)
View Answer play_arrow
-
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)
View Answer play_arrow
-
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)\[\overset{6}{\mathop{HC}}\,\equiv
\overset{5}{\mathop{C}}\,-\overset{4}{\mathop{CH}}\,=\overset{3}{\mathop{CH}}\,-\overset{2}{\mathop{CH}}\,=\overset{1}{\mathop{C{{H}_{2}}}}\,\]
View Answer play_arrow
-
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
View Answer play_arrow
-
Write the structural
formula of :
(a) o-Ethylanisole
(b) p-Nitroaniline
(c) 2,
3-Dibromo-1-phenylpentane
(d) 4-Ethyl-1-fluoro-2-nitrobenzene
View Answer play_arrow
-
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)\[C{{H}_{3}}-Cu\]
View Answer play_arrow
-
Giving justification,
categories the following molecules/ions as nucleophile or electrophile:
\[H{{S}^{-}},B{{F}_{3}},{{C}_{2}}{{H}_{5}}{{O}^{-}},{{(C{{H}_{3}})}_{3}}N_{\centerdot
}^{\centerdot };C{{l}^{+}},\]
\[C{{H}_{3}}-C=O,{{H}_{2}}N_{\centerdot }^{{{\centerdot
}^{-}}},\overset{+}{\mathop{N{{O}_{2}}}}\,\]
View Answer play_arrow
-
Identify electrophilic centre in the following:
View Answer play_arrow
-
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) \[{{H}_{3}}C-OH,{{H}_{3}}C-SH\]
View Answer play_arrow
-
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?
View Answer play_arrow
-
Write resonance structures of \[C{{H}_{3}}CO{{O}^{-}}\]and
show the movement of electrons by curved arrows.
View Answer play_arrow
-
Write the resonance structures of\[{{H}_{2}}C=CH-CHO.\]Indicate
relative stability of the contributing structures.
View Answer play_arrow
-
Explain why the following two structures, I and II cannot be
the major contributors to the real structure of\[C{{H}_{3}}COOC{{H}_{3}}\].
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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).
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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?
View Answer play_arrow
-
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) \[{{C}_{6}}{{H}_{6}}\]
View Answer play_arrow
-
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)\[HCONHC{{H}_{3}}\]
View Answer play_arrow
-
Write bond line formulae for:
(i) Isopropylalcohol
(ii) 2,3-Dimethylbutanal
(iii) Heptan-4-one.
View Answer play_arrow
-
Give the IUPAC names
of the following compounds:
(i)
(ii)
(iii)
(iv)
(v)
(vi) \[C{{l}_{2}}CHC{{H}_{2}}OH\]
View Answer play_arrow
-
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.
View Answer play_arrow
-
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)
\[H-CH=C{{H}_{2}}\]
View Answer play_arrow
-
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.
View Answer play_arrow
-
Identify the
functional groups in the following compounds:
(i)
(ii)
(iii)
View Answer play_arrow
-
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?
View Answer play_arrow
-
Explain why alkyl groups act as electron donors when attached
to a \[\pi \]-system.
View Answer play_arrow
-
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)\[C{{H}_{3}}CH=C{{H}^{+}}C{{H}_{2}}\]
View Answer play_arrow
-
What are electrophiles and nucleophiles? Explain with examples.
View Answer play_arrow
-
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) \[{{C}_{6}}{{H}_{6}}+\mathbf{C}{{\mathbf{H}}_{\mathbf{3}}}\overset{\mathbf{+}}{\mathop{\mathbf{CO}}}\,\xrightarrow{{}}{{C}_{6}}{{H}_{5}}COC{{H}_{3}}\]
View Answer play_arrow
-
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)\[{{(C{{H}_{3}})}_{3}}C-C{{H}_{2}}OH+HBr\to
(C{{H}_{3}})CBrC{{H}_{2}}C{{H}_{3}}\]
View Answer play_arrow
-
What is the
relationship between the members of the following pairs of structures? Are they
structural orgeometrical isomers or resonance contributors?
(i)
(ii)
(iii)
View Answer play_arrow
-
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)
View Answer play_arrow
-
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)
\[C{{H}_{3}}C{{H}_{2}}COOH>{{(C{{H}_{3}})}_{2}}CHCOOH\]\[>{{(C{{H}_{3}})}_{3}}CCOOH\]
View Answer play_arrow
-
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)
\[C{{H}_{3}}C{{H}_{2}}COOH>{{(C{{H}_{3}})}_{2}}CHCOOH\]\[>{{(C{{H}_{3}})}_{3}}CCOOH\]
View Answer play_arrow
-
Give a brief
description of the principles of the following techniques taking an example in
each case:
(a) crystallisation
(b)
distillation
(c) chromatography
View Answer play_arrow
-
Describe the method, which can be used to separate two compounds
with different solubilities in a solvent S.
View Answer play_arrow
-
What is the difference between distillation, distillation under
reduced pressure and steam distillation?
View Answer play_arrow
-
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.
View Answer play_arrow
-
Discuss the principle of estimation of halogens, sulphur and
phosphorus present in the organic compound.
View Answer play_arrow
-
Explain the principle of paper chromatography.
View Answer play_arrow
-
Why is nitric acid added to sodium extract before adding
silver nitrate for testing halogens?
View Answer play_arrow
-
Explain the reason for the fusion of organic compound with
metallic sodium for testing nitrogen, sulphur and halogens.
View Answer play_arrow
-
Name a suitable technique of separation of components from a
mixture of calcium sulphate and camphor.
View Answer play_arrow
-
Explain why an organic liquid vaporises at a temperature
below its boiling point in its steam distillation?
View Answer play_arrow
-
Will \[CC{{l}_{4}}\] give white ppt. of \[AgCl\] on heating
with silver nitrate? Give reason for your answer.
View Answer play_arrow
-
Why a solution of potassium hydroxide used to absorb carbon
dioxide evolved during the estimation of carbon present in an organic compound?
View Answer play_arrow
-
Why is it necessary to use acetic acid and not sulphuric acid
for acidification of sodium extract for testing sulphur by lead acetate test?
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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)\[~s{{p}^{3}}-s{{p}^{3}}\]
View Answer play_arrow
-
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)
\[F{{e}_{3}}{{[Fe{{(CN)}_{6}}]}_{6}}\]
View Answer play_arrow
-
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)
\[C{{H}_{3}}\overset{+}{\mathop{C}}\,HC{{H}_{2}}C{{H}_{3}}\]
View Answer play_arrow
-
The best and latest technique
for isolation, purification and separation of organic compound is:
(a) crystallization (b) distillation (c)
sublimation (d)chromatography
View Answer play_arrow
-
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
-
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
-
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
-
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
View Answer play_arrow
-
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) \[C{{H}_{3}}-C{{H}_{2}}-CH={{\,}^{*}}C{{H}_{2}}\]
View Answer play_arrow
-
question_answer70)
In which of the following,
functional groups isomerism is not possible?
(a) Alcohols (b)
Aldehydes (c) Alkyl halides (d) Cyanides
View Answer play_arrow
-
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
View Answer play_arrow
-
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
View Answer play_arrow
-
question_answer73)
The principle involved in paper
chromatography is :
(a) adsorption (b)
partition (c) solubility (d)
volatility
View Answer play_arrow
-
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
View Answer play_arrow
-
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
View Answer play_arrow
-
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)
\[{{\,}^{*}}C{{H}_{3}}-C{{H}_{2}}-C{{H}_{3}}\]
View Answer play_arrow
-
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)
View Answer play_arrow
-
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) \[1{}^\circ \text{ }Carbanion\]
View Answer play_arrow
-
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)
View Answer play_arrow
-
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
View Answer play_arrow
-
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)
\[C{{H}_{2}}=C=C{{H}_{2}}\]
View Answer play_arrow
-
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)
View Answer play_arrow
-
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:
\[\text{I}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-H\]
\[\text{II}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-\overset{\overset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-C{{H}_{3}}\]
\[\text{III}\text{.}\]\[C{{H}_{3}}-C{{H}_{2}}-\underset{\underset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-C{{H}_{2}}-C{{H}_{3}}\]
\[\text{IV}\text{.}\]\[C{{H}_{3}}-\underset{\underset{\text{C}{{\text{H}}_{\text{3}}}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{CH}}\,-C{{H}_{2}}-\underset{\underset{\text{O}}{\mathop{\text{
}\!\!|\!\!\text{ }\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,-H\]
View Answer play_arrow
-
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
View Answer play_arrow
-
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
View Answer play_arrow
-
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
View Answer play_arrow
-
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
View Answer play_arrow
-
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?
View Answer play_arrow
-
question_answer89)
Identify the pairs of compounds
which are functional group isomers.
View Answer play_arrow
-
question_answer90)
Identify the pairs of compounds
that represent position isomerism.
View Answer play_arrow
-
question_answer91)
Identify the pairs of compounds
that represent chain isomerism.
View Answer play_arrow
-
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\[HN{{O}_{3}}\]?
View Answer play_arrow
-
question_answer93)
What is the hybridisation of
each carbon in \[{{H}_{2}}C=C=C{{H}_{2}}?\]
View Answer play_arrow
-
question_answer94)
Explain, how is the electro negativity
of carbon atoms related to their state of hybridisation in an organic compound?
View Answer play_arrow
-
question_answer95)
Show the polarisation of
carbon-magnesium bond in the following structure :
\[C{{H}_{3}}-C{{H}_{2}}-C{{H}_{2}}-C{{H}_{2}}-Mg-X.\]
View Answer play_arrow
-
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
View Answer play_arrow
-
question_answer97)
Which of the following selected
chains is correct to name the given compound according to IUPAC system?
View Answer play_arrow
-
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.
View Answer play_arrow
-
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."
View Answer play_arrow
-
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.
View Answer play_arrow
-
question_answer101)
Which of the following ions is more
stable? Use resonance to explain your answer.
View Answer play_arrow
-
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.
View Answer play_arrow
-
question_answer103)
Write structures of various carbocations
that can be obtained from 2-methylbutane. Arrange these carbocations in order
of increasing stability.
View Answer play_arrow
-
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.
View Answer play_arrow
-
question_answer105)
Name the compounds whose line
formulae are given below:
(i) (ii)
View Answer play_arrow
-
question_answer106)
Write structural formulae for
compounds named as :
(a) 1-Bromoheptane
(b) 5-Bromoheptanoic acid
View Answer play_arrow
-
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) \[C{{H}_{2}}=CH-\underset{\underset{\text{H}}{\mathop{\text{
}\!\!|\!\!\text{ }}}\,}{\mathop{C}}\,=O\]
View Answer play_arrow
-
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) \[\overset{O-}{\mathop{C{{H}_{3}}}}\,,\overset{O-}{\mathop{C{{H}_{2}}Cl}}\,,\overset{O-}{\mathop{CHC{{l}_{2}}}}\,,\overset{O-}{\mathop{CC{{l}_{3}}}}\,\]
View Answer play_arrow
-
question_answer109)
Give three points of differences
between inductive effect and resonance effect.
View Answer play_arrow
-
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) \[C{{H}_{3}}CH=CHC{{H}_{2}}N{{H}_{2}}\]
View Answer play_arrow
-
question_answer111)
Why does \[S{{O}_{3}}\] act as
an electrophile?
View Answer play_arrow
-
question_answer112)
Resonance structures of propenal
are given below. Which of these resonating structures is more stable? Give
reason for your answer.
\[C{{H}_{2}}=\underset{I}{\mathop{CH}}\,-CH=O\overset{{}}{\longleftrightarrow}\overset{O-}{\mathop{C{{H}_{2}}}}\,-\underset{II}{\mathop{CH}}\,=CH-\overset{O-}{\mathop{O}}\,\]
View Answer play_arrow
-
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.
View Answer play_arrow
-
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 \[\underset{(B)}{\mathop{C{{H}_{3}}CO\overset{O-}{\mathop{O}}\,}}\,\]
View Answer play_arrow
-
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
|
View Answer play_arrow
-
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
|
View Answer play_arrow
-
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
|
View Answer play_arrow
-
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
|
View Answer play_arrow
-
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
|
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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?
View Answer play_arrow
-
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?
View Answer play_arrow
-
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.
View Answer play_arrow
-
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.
View Answer play_arrow
-
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?
View Answer play_arrow
-
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?
View Answer play_arrow