Hydrocarbons PYQs Set 2 (PDF)

Set 2 of 15 · Questions 31-60 of 435

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NEET Chemistry · Hydrocarbons · Set 2 (Q31-60)

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31.
Presence of a nitro group in a benzene ring
1. (1) $activates the ring towards electrophilic substitution$
2. (2) $renders the ring basic$
3. (3) $deactivates the ring towards nucleophilic substitution.$
4. (4) $deactivates the ring towards electrophilic substitution.$
32.
Which one of the following methods is neither meant for the synthesis nor for separation of amines ?
1. (1) $Hinsberg method$
2. (2) $Hofmann method$
3. (3) $Wurtz reaction$
4. (4) $None of these$
33.
Among the following four compounds the acidity order is :
(i) Phenol
(ii) Methyl phenol
(iii) Meta-nitrophenol
(iv) Para-nitrophenol
1. (1) $(iv) > (iii) > (i) > (ii)$
2. (2) $(iii) > (iv) > (i) > (ii)$
3. (3) $(i) > (iv) > (iii) > (ii)$
4. (4) $(ii) > (i) > (iii) > (iv)$
34.
Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne?
1. (1) $NaNH2$
2. (2) $HCI$
3. (3) $O2$
4. (4) $Br2$
35.
Which of the following alkane cannot be made in good yield by Wurtz reaction?
1. (1) $2,3-Dimethylbutane$
2. (2) $n -Heptane$
3. (3) $n -Butane$
4. (4) $n -Hexane$
36.
Select the true statement about benzene amongst the following
1. (1) $because of unsaturation benzene easily undergoes addition$
2. (2) $there are two types of C - C bonds in benzene molecule$
3. (3) $there is cyclic delocalisation of π ‐electrons in benzene$
4. (4) $monosubstitution of benzene gives three isomeric products.$
37.
Which of the following molecule is not aromatic?
1. (1)
2. (2)
3. (3)
4. (4)
38.
Arrange benzene, $n$ -hexane and ethyne in decreasing order of their acidic behaviour.
1. (1) $Benzene > n -hexane > ethyne$
2. (2) $n -Hexane > benzene > ethyne$
3. (3) $Ethyne > n -hexane > benzene$
4. (4) $Ethyne > benzene > n -hexane$
39.
The suitable reagents for the conversion of methane into methyl iodide are
1. (1) $I_{2}, HNO_{2}$
2. (2) $I_{2}, H_{2} O_{2}$
3. (3) $I_{2}, H_{2} O$
4. (4) $I_{2}, HNO_{3}$
40.
n-Propyl chloride reacts with sodium metal in dry ether to give
1. (1) $CH_{3} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{3}$
2. (2) $CH_{3} - CH_{2} - CH_{3}$
3. (3) $CH_{3} - CH_{2} - CH_{2} - CH_{3}$
4. (4) $CH_{3} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{3}$
41.
Weight (g) of two moles of the organic compound, which is obtained by heating sodium
ethanoate with sodium hydroxide in presence of calcium oxide is:
1. (1) $18$
2. (2) $16$
3. (3) $32$
4. (4) $30$
42.
Identify the correct statements with respect to cis/trans-2butene from the following
I. cis-2- Butene is more polar than trans - 2 Butene
II. melting point of cis- 2- Butene is greater than that of trans- 2- Butene
III. boiling point of cis- 2- Butene is greater than that of trans- 2-Butene
Correct answer is
1. (1) $I, II only$
2. (2) $II, III only$
3. (3) $I, III only$
4. (4) $I, II, III$
43.
Wurtz reaction of bromoethane gives $n$ -butane. Sodium salt of $X$ on heating with sodalime also results in $n$ -butane. Compound $X$ is
1. (1) $CH_{3} CH_{2} CH_{2} COOH$
2. (2) $CH_{3} (CH_{2})_{3} COOH$
3. (3) $CH_{3} (CH_{2})_{4} COOH$
4. (4) $CH_{3} CH_{2} COOH$
44.
Which of the following compounds will be most easily attacked by an electrophile?
1. (1)
2. (2)
3. (3)
4. (4)
45.
Which one of the following reactions gives the product with less number of carbon atoms than the starting material?
1. (1) $R - X \to Na / ether$
2. (2) $R C O_{2} N a N a O H, C a O Δ$
3. (3) $RCO_{2} K \to electrolysis$
4. (4) $R - X + H_{2} \to Zn, HCl$
46.
The arenium ion which is not involved in the bromination of Aniline is
1. (1)
2. (2)
3. (3)
4. (4)
47.
The cylindrical shape of an alkyne is due to
1. (1) $two sigma C - C and one π C - C bonds$
2. (2) $one sigma C - C and two π C - C bonds (a) (b)$
3. (3) $three sigma C - C bonds$
4. (4) $three π C - C bonds.$
48.
Which is the correct symbol relating the two Kekule structures of benzene?
1. (1)
2. (2) $\to$
3. (3) $\equiv$
4. (4)
49.
Replacement of $Cl$ of chlorobenzene to give phenol requires drastic conditions, but $Cl$ of 2,4 -dinitrochlorobenzene is readily replaced. This is because
1. (1) $- NO_{2} group makes the ring electron rich at ortho and para positions$
2. (2) $- NO_{2} group withdraws electrons from meta position$
3. (3) $- NO_{2} donates electrons at meta position$
4. (4) $- NO_{2} withdraws electrons from ortho and para positions.$
50.
Which of the following compounds will not undergo Friedal-Craft’s reaction easily :
1. (1) $Xylene$
2. (2) $Nitrobenzene$
3. (3) $Toluene$
4. (4) $Cumene$
51.
The order of decreasing reactivity towards an electrophilic reagent, for the following compounds, is
(i) Benzene (ii) Toluene
(iii) Chlorobenzene (iv) Phenol
1. (1) $(i) > (ii) > (iii) > (iv)$
2. (2) $(ii) > (iv) > (i) > (iii)$
3. (3) $(iv) > (iii) > (ii) > (i)$
4. (4) $(iv) > (ii) > (i) > (iii)$
52.
Assertion : In strongly acidic solutions, aniline becomes more reactive towards electrophilic reagents.
Reason : The amino group being completely protonated in strongly acidic solution, the lone pair of electrons on the nitrogen is no longer available for resonance.
1. (1) $Both Assertion and Reason are true and Reason is the correct explanation of Assertion.$
2. (2) $Both Assertion and Reason are true but Reason is not correct explanation of Assertion.$
3. (3) $Assertion is true but Reason is false.$
4. (4) $Assertion is false but Reason is true.$
53.
Which of the following is Lindlar catalyst?
1. (1) $Zinc chloride and HCl$
2. (2) $Cold dilute solution of KMnO_{4}$
3. (3) $Sodium and Liquid NH_{3}$
4. (4) $Partially deactivated palladised charcoal$
54.
Which one of the following is the most energetic conformation of cyclohexane?
1. (1) $Boat$
2. (2) $Twisted boat$
3. (3) $Chair$
4. (4) $Half-chair$
55.
Which is the most suitable reagent among the following to distinguish compound (3) from rest of the compounds?
(1) $C H_{3} - C \equiv C - C H_{3}$
(2) $C H_{3} - C H_{2} - C H_{2} - C H_{3}$
(3) $C H_{3} - C H_{2} C \equiv C H$
(4) $C H_{3} - C H = C H_{2}$
1. (1) $Bromine in carbon tetrachloride$
2. (2) $Bromine in acetic acid$
3. (3) $A ik . K M n O_{4}$
4. (4) $Ammoniacal silver nitrate$
56.
Arrange the following in the correct order of their acidic strength
$H_{2} C = CH_{2}$ $CH \equiv CH$ $CH_{3} - C \equiv CH$ $CH_{3} - CH_{3}$
I II III IV
1. (1) $I < II < III < IV$
2. (2) $IV < I < III < II$
3. (3) $IV < III < II < I$
4. (4) $II < III < IV < I$
57.
Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons
by
1. (1) $oxidation$
2. (2) $cracking$
3. (3) $distillation under reduced pressure$
4. (4) $hydrolysis.$
58.
Consider the nitration of benzene using mixed conc. $H_{2} S O_{4}$ and $H N O_{3}$ . If a
large amount of $K H S O_{4}$ is added to the mixture, the rate of nitration will be
1. (1) $unchanged$
2. (2) $doubled$
3. (3) $faster$
4. (4) $slower.$
59.
$Match the LIST-I with LIST-II Name reaction Product obtainable$
$LIST-I$ $LIST- II$
$A. Swarts reaction$ $I. Ethyl benzene$
$B. Sandmeyer's reaction$ $II.$
$Ethyl iodide C. Wurtz Fittig reaction III. Cyanobenzene D. Finkelstein reaction IV. Ethyl fluoride Choose the correct answer from the options given below:$
1. (1) $A-II, B-I, C-III, D-IV$
2. (2) $A-II, B-III, C-I, D-IV$
3. (3) $A-IV, B-I, C-III, D-II$
4. (4) $A-IV, B-III, C-I, D-II$
60.
Which reagent converts propene to l‐propanol?
1. (1) $H_{2} O, H_{2} S O_{4}$
2. (2) $B_{2} H_{6}, H_{2} O_{2}, O H^{-}$
3. (3) $H g (O A c)_{2}, N a B H_{4} / H_{2} O$
4. (4) $A q . K O H$