$ \text {Arrange the following alkenes in decreasing order of stability. } $
Choose the correct answer from the options given below:
III $>$ I $>$ II $>$ IV
III $>$ II $>$ I $>$ IV
I $>$ III $>$ II $>$ IV
$\mathrm{I}>\mathrm{III}>\mathrm{IV}>\mathrm{II}$
But-2-yne and hydrogen (one mole each) are separately treated with (i) $\mathrm{Pd} / \mathrm{C}$ and (ii) $\mathrm{Na} /$ liq. $\mathrm{NH}_3$ to give the products X and Y respectively.
Identify the incorrect statements.
A. X and Y are stereoisomers.
B. Dipole moment of $X$ is zero.
C. Boiling point of X is higher than Y .
D. X and Y react with $\mathrm{O}_3 / \mathrm{Zn}+\mathrm{H}_2 \mathrm{O}$ to give different products.
Choose the correct answer from the options given below :
B and D Only
A and C Only
A and B Only
B and C Only
$ \text { The final product }[\mathrm{B}] \text { is : } $
Consider the following reaction :
The product Y formed is :
2-methylhex-3-yne
5-methylhex-2-yne
Isopropylbut-1-yne
2-methylhex-2-yne
The dibromo compound $[\mathrm{P}]$ (molecular formula: $\mathrm{C}_9 \mathrm{H}_{10} \mathrm{Br}_2$ ) when heated with excess sodamide followed by treatment with dilute HCl gives [Q]. On warming [Q] with mercuric sulphate and dilute sulphuric acid yield $[R]$ which gives positive Iodoform test but negative Tollen's test. The compound $[\mathrm{P}]$ is :
Given below are two statements :
Statement I : Benzene is nitrated to give nitrobenzene, which on further treatment $
\text { with } \mathrm{CH}_3 \mathrm{COCl} / \mathrm{AlCl}_3 \text { will give }
$ 
Statement II : $-\mathrm{NO}_2$ group is a $m$-directing, and deactivating group.
In the light of the above statements, choose the most appropriate answer from the options given below
Statement I is incorrect but Statement II is correct
Both Statement I and Statement II are correct
Both Statement I and Statement II are incorrect
Statement I is correct but Statement II is incorrect
80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to 273 K occupy 224 mL . When the system is treated with KOH solution, the volume decreases to 64 mL . The formula of the hydrocarbon is :
$\mathrm{C}_2 \mathrm{H}_2$
$\mathrm{C}_2 \mathrm{H}_4$
$\mathrm{C}_4 \mathrm{H}_{10}$
$\mathrm{C}_2 \mathrm{H}_6$
Consider the following reaction of benzene.
In compound $(Q)$, the percentage of oxygen is $\_\_\_\_$ %. (Nearest integer)
Explanation:
Molecular mass of compound $Q$ is $157$.
In $Q$, oxygen contributes mass $16$ (for one oxygen atom).
So, percentage of oxygen in $Q$ is $\% \text{ of oxygen in product ' } Q \text{ ' is }=\frac{16}{157} \times 100=10.19 \%$
Nearest integer $=10$%.
The cycloalkene $(\mathrm{X})$ on bromination consumes one mole of bromine per mole of $(\mathrm{X})$ and gives the product $(\mathrm{Y})$ in which $\mathrm{C}: \mathrm{Br}$ ratio is 3:1. The percentage of bromine in the product $(\mathrm{Y})$ is $\_\_\_\_$ %. (Nearest integer)
(Given : molar mass in $\mathrm{g} \mathrm{mol}^{-1} \mathrm{H}: 1, \mathrm{C}: 12, \mathrm{O}: 16, \mathrm{Br}: 80$ )
Explanation:
Bromination of a cycloalkene (one double bond) consumes 1 mole of $Br_2$ per mole of alkene, which means 2 bromine atoms add across the double bond.
So, product $(Y)$ is a dibromo compound.
Given in $(Y)$, the ratio $\mathrm{C}:\mathrm{Br} = 3:1$.
Let number of carbon atoms $= n$.
Number of bromine atoms $= 2$.
So,
$ \frac{n}{2} = \frac{3}{1} \;\Rightarrow\; n = 6 $
Hence $(Y)$ has formula:
$ \mathrm{C_6H_{10}Br_2} $
(since cyclohexene is $\mathrm{C_6H_{10}}$ and it adds $Br_2$)
Now molar mass of $(Y)$:
Carbon: $6 \times 12 = 72$
Hydrogen: $10 \times 1 = 10$
Bromine: $2 \times 80 = 160$
Total molar mass:
$ 72 + 10 + 160 = 242\ \mathrm{g\,mol^{-1}} $
Percentage of bromine:
$ \%Br = \frac{160}{242}\times 100 \approx 66.12\% $
Nearest integer $= \boxed{66\%}$.
The reactions which cannot be applied to prepare an alkene by elimination, are
Choose the correct answer from the options given below:
Given below are two statements:
Statement I : Ozonolysis followed by treatment with $\mathrm{Zn}, \mathrm{H}_2 \mathrm{O}$ of cis-2-butene gives ethanal.
Statement II : The product obtained by ozonolysis followed by treatment with $\mathrm{Zn}, \mathrm{H}_2 \mathrm{O}$ of 3, 6-dimethyloct-4-ene has no chiral carbon atom.
In the light of the above statements, choose the correct answer from the options given below
Predict the major product of the following reaction sequence:-
$ \text { Which compound would give 3-methyl-6-oxoheptanal upon ozonolysis? } $
Given below are two statements :
Statement (I) : Neopentane forms only one monosubstituted derivative.
Statement (II) : Melting point of neopentane is higher than n-pentane.
In the light of the above statements, choose the most appropriate answer from the options given below :
Match List - I with List - II.
| List - I (Reaction) |
List - II (Name of reaction) |
||
|---|---|---|---|
| (A) |  |
(I) | Lucas reaction |
| (B) | $ \mathrm{ArN}_2^{+} \mathrm{X}^{-} \xrightarrow[\mathrm{HCl}]{\mathrm{Cu}} \mathrm{ArCl}+\mathrm{N}_2 \uparrow+\mathrm{CuX} $ |
(II) | Finkelstein reaction |
| (C) | $ \mathrm{C}_2 \mathrm{H}_5 \mathrm{Br}+\mathrm{NaI} \xrightarrow[\text { Acetone }]{\text { Dry }} \mathrm{C}_2 \mathrm{H}_5 \mathrm{I}+\mathrm{NaBr} $ |
(III) | Fittig reaction |
| (D) | $ \mathrm{CH}_3 \mathrm{C}(\mathrm{OH})\left(\mathrm{CH}_3\right) \mathrm{CH}_3 \xrightarrow[\mathrm{ZnCl}_2]{\mathrm{HCl}} \mathrm{CH}_3 \mathrm{C}(\mathrm{Cl})\left(\mathrm{CH}_3\right) \mathrm{CH}_3 $ |
(IV) | Gatterman reaction |
$ \text { Choose the correct answer from the options given below : } $
Total number of sigma (σ) _______ and pi(π) ______ bonds respectively present in hex-1-en-4-yne are:
14 and 3
11 and 3
13 and 3
3 and 13
The product B formed in the following reaction sequence is:
Identify product [A], [B] and [C] in the following reaction sequence.
$\mathrm{CH}_3-\mathrm{C} \equiv \mathrm{CH} \xrightarrow[\mathrm{H}_2]{\mathrm{Pd} / \mathrm{C}}[\mathrm{A}] \xrightarrow[\text { (ii) } \mathrm{Zn}, \mathrm{H}_2 \mathrm{O}]{\text { (i) } \mathrm{O}_3}[\mathrm{~B}]+[\mathrm{C}]$
[A]: CH3—CH=CH2, [B]: CH3CHO, [C]: CH3CH2OH
[A]: CH3—CH=CH2, [B]: CH3CHO, [C]: HCHO
[A]: CH3CH2CH3, [B]: CH3CHO, [C]: HCHO
The product $(\mathrm{A})$ formed in the following reaction sequence is
Match List - I with List - II
| List - I (Isomers of $\mathrm{C}_{10} \mathrm{H}_{14}$ ) |
List - II (Ozonolysis product) |
||
|---|---|---|---|
| (A) |  |
(I) |  |
| (B) |  |
(II) |  |
| (C) |  |
(III) |  |
| (D) |  |
(IV) |  |
Choose the correct answer from the options given below :
Match the List - I with List - II
| List - I Name reaction |
List - II Product obtainable |
||
|---|---|---|---|
| (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:
When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is :
The alkane from below having two secondary hydrogens is :
Given below are two statements :
Statement I : One mole of propyne reacts with excess of sodium to liberate half a mole of $\mathrm{H}_2$ gas.
Statement II : Four g of propyne reacts with $\mathrm{NaNH}_2$ to liberate $\mathrm{NH}_3$ gas which occupies 224 mL at STP.
In the light of the above statements, choose the most appropriate answer from the options given below :
Isomeric hydrocarbons → negative Baeyer’s test
(Molecular formula C9H12)
The total number of isomers from above with four different non-aliphatic substitution sites is -
Explanation:
Molecular formula of isomeric hydrocarbon $\to C_9H_{12}$ - Negative Baeyer's test
Baeyers test is given by compounds that contain readily active carbon-carbon double bond.
So, in a negative Baeyer's test, there is no readily active c = c.
Compounds that give negative Baeyer's test are alkanes and aromatic compounds.
C$_9$H$_{12}$ compound is not an alkane
(Alkane general formula C$_n$H$_{2n+2}$)
Hydrocarbons with the formula C$_9$H$_{12}$ are considered as aromatic and isomers of substituted benzene rings.
The possible isomers of C$_9$H$_{12}$ are
From these, total number of the isomers with four different non-aliphatic substitution sites are 2
 |
 |
 |
| Four positions (1,2,3,4) are different. So, it contain four different non-aliphatic substitution sites. | Four position (1,2,3,4) are different. So, it contain four different non-aliphatic substitution sites. | Four position (1,2,3,4) are not different. So, it contain four different non-aliphatic substitution sites. |
The sum of sigma (σ) and pi (π) bonds in Hex-1,3-dien-5-yne is ________.
Explanation:
The compound given is hex-1,3-dien-5-yne structure is
A doble bond has one $\pi$ bond and one sigma bond.
A triple bond has one sigma bond and two $\pi$ bonds.
For the one triple bond, number of $\pi$ bonds = 2
For one double bond, number of $\pi$ bond = 1
For two double bonds, number of $\pi$ bonds = 2
So, total number of $\pi$ bonds = 2 + 2 = 4
For sigma bonds, count all carbon - carbon bonds and carbon - hydrogen bonds except the $\pi$ bonds in double bonds and triple bond.
The total number of sigma bonds = 11
So, total number of bonds:
$\sigma=11$
$\pi=4$
Sum of $\sigma$ and $\pi$ bonds
$=11+4=15$
The compound with molecular formula $\mathrm{C}_6 \mathrm{H}_6$, which gives only one monobromo derivative and takes up four moles of hydrogen per mole for complete hydrogenation has _________ $\pi$ electrons.
Explanation:
The incorrect statement regarding ethyne is
Identify the product A and product B in the following set of reactions.
Given below are two statements :
Statement (I) : $\mathrm{S}_{\mathrm{N}} 2$ reactions are 'stereospecific', indicating that they result in the formation of only one stereo-isomer as the product.
Statement (II) : $\mathrm{S}_{\mathrm{N}} 1$ reactions generally result in formation of product as racemic mixtures.
In the light of the above statements, choose the correct answer from the options given below :
In the given compound, the number of 2$^\circ$ carbon atom/s is ________.
Consider the above chemical reaction. Product "A" is :
Given below are two statements :
Statement I : Nitration of benzene involves the following step -
Statement II : Use of Lewis base promotes the electrophilic substitution of benzene.
In the light of the above statements, choose the most appropriate answer from the options given below :
In the above chemical reaction sequence "$\mathrm{A}$" and "$\mathrm{B}$" respectively are
Acid D formed in above reaction is :
Major product of the following reaction is -
Products A and B formed in the following set of reactions are
Compound A formed in the following reaction reacts with B gives the product C. Find out A and B.
In the given reactions, identify the reagent A and reagent B.
Identify product A and product B :
The final product A formed in the following multistep reaction sequence is
The final product A, formed in the following reaction sequence is:
Major product B of the following reaction has ________ $\pi$-bond.
Explanation:
Number of $\pi$ bonds in B = 5
The major product of the following reaction is P.
$\mathrm{CH}_3 \mathrm{C}\equiv\mathrm{C}-\mathrm{CH}_3$ $\xrightarrow[\substack{\text { (ii) dil. } \mathrm{KMnO}_4 \\ 273 \mathrm{~K}}]{\text { (i) } \mathrm{Na} \text { /liq. } \mathrm{NH}_3}$ 'P'
Number of oxygen atoms present in product '$\mathrm{P}$' is _______. (nearest integer)
Explanation:
Product is
Number of oxygen atoms = 2
The major products from the following reaction sequence are product A and product B.
The total sum of $\pi$ electrons in product A and product B are __________ (nearest integer)
Explanation:
Number of $\pi$ electron in A = 2
Number of $\pi$ electron in B = 6
Total Number of $\pi$ electron in (A) and (B) = 8
Consider the given reaction. The total number of oxygen atom/s present per molecule of the product $(\mathrm{P})$ is _________.
Explanation:
Hence, total number of oxygen atom present per molecule 
is 1.
In the above reaction, left hand side and right hand side rings are named as '$\mathrm{A}$' and 'B' respectively. They undergo ring expansion. The correct statement for this process is:
The major product formed in the following reaction is
Choose the correct answer from the options given below :
