Catalytic Hydrogenation of Aromatics

Q. What is the decreasing order of enthalpy of hydrogenation of the following compounds?

1. III < IV < I < II
2. IV < III < II < I
3. I < III < II < IV
4. II < I < IV < III

Q.
The above reaction is an example of

1. Catalytic hydrogenation
2. Birch reduction
3. Dehydrogenation
4. Dehydrohalogenation

Q. The order of the heat of hydrogenation in following compound is:

1. I < II < IV < III
2. III < IV < II < I
3. III< IV < I < II
4. II < IV < I < III

Q. n-propyl benzene +(KMnO4/ KOH)---->P +(H3O+)----> Q

Q. Catalytic hydrogenation of benzene gives :

1. Xylene
2. Cyclohexane
3. Benzoic acid
4. Toulene

Q. Assertion :Alkyl benzene is not prepared by Friedel-Craft's alkylation of benzene. Reason: Alkyl halides are less reactive than acyl halides.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Write the reactions of $D$−glucose which can’t be explained by its open-chain structure. How can the cyclic structure of glucose explain these reactions?

Q. Give reasons for the following:
$ICl$ is more reactive than $I_2$.

Q.

A hydrocarbon of formula $C_6{H}_{10}$ absorbs only one molecule of H2upon catalytic hydrogenation. Upon ozonolysis, the hydrocarbon yields

The hydrocarbon is

1. Cyclohexane

2. Benzene

3. Cyclohexene

4. Cyclobutane

Q. Which of the following orders is correct for heat of hydrogenation of these compounds?

1. $I>II>III$
2. $III>II>I$
3. $II>III>I$
4. $III>I>II$

Q. Explain the mechanism of $S_{N}1$ reaction taking 2-bromo-2methyl propane (t-buty bromide)

Q. Write the reactions of $D$−glucose which can’t be explained by its open-chain structure. How can the cyclic structure of glucose explain these reactions?

Q. Assertion :$KI{O}_3$ reacts with $KI$ to liberate iodine which is titrated with standard hypo solution. The reactions are:
(i) $I{O}_3^{-}\to I_2$ (Valency factor = 5/3)
(ii) $I_2+S_2{O}_3^2\to S_4{O}_6^{2-}+I^{-}$ (Valence factor $=$2)
Milliequivalent of hypo$=$ meq. of $I_2=$meq. of $I{O}_3^{-}$.
Reason: Valency factor of $I_2$ in both the equation are different, therefore we cannot compare milliequivalents in sequence.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is incorrect but Reason is correct
4. Both Assertion and Reason are correct

Q. Addition of small amount of ($C_2{H}_5{)}_4$Pb to a mixture of methane and chlorine, starts the reaction at ${140}^{\circ }$instead of the usual minimum ${250}^{\circ }$C.
If true enter 1, if false enter 0.

Q. For the given pair of reactions, predict the faster one and mechanism ($S_{N}1$ or $S_{N}2$) under which reaction will occur at faster rate.

1. $\left(i\right)<\left(ii\right)$
2. $\left(i\right)=\left(ii\right)$
3. None of these
4. $\left(i\right)>\left(ii\right)$

Q. Consider the following reactions:


Which of the following is/are true regarding the products formed?

1. 
2. 
3. 
4. 

Q. In the given reactions, the rate of reaction of $\left(I\right)$ is faster than that of $\left(II\right)$. By which mechanism do both reactions proceed?

1. E1
2. E2
3. E1cB
4. $\alpha$-Elimination

Q.

A hydrocarbon of formula $C_6{H}_{10}$ absorbs only one molecule of H2upon catalytic hydrogenation. Upon ozonolysis, the hydrocarbon yields

The hydrocarbon is

1. Cyclohexane

2. Benzene

3. Cyclobutane

4. Cyclohexene

Q. (-)-1-chloro-1-phenylethane in toluene racemises slowly in the presence of small amount of $Sb{Cl}_5$, due to the formation of:

1. carbocation
2. cabanion
3. carbene
4. free-radical

Q. What are the products $\left(x\right)$ and $\left(y\right)$ formed in the above reaction?

Q. Assertion :Friedel-Crafts reaction of benzene with n-propyl chloride on heating produce isopropyl benzene. Reason: Benzene undergoes electrophilic susbstitution easily.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q. Catalytic hydrogenation of either cis or trans 3, 4-dimethyl-3- heptene results in racemic mixture of product.If true enter 1 else 0.

Q. Which of the following is(are) example(s) of Sandmeyer reaction?

1. $C_6{H}_5{N}_2^{+}C{l}^{-}\to C_6{H}_{5}Cl$
2. $C_6{H}_5{N}_2^{+}C{l}^{-}\to C_6{H}_{5}OH$
3. $C_6{H}_5{N}_2^{+}C{l}^{-}\to C_6{H}_{5}CN$
4. $C_6{H}_5{N}_2^{+}{I}^{-}\to C_6{H}_{5}I$

Q. A biologically active compound bombykol $\left(C_{16}{H}_{30}O\right)$ is obtained from a natural source. The structure of the compound is determined by the following reactions:
(a) On hydrogenation, bombykol gives a compound $\left(A\right)$, $C_{16}{H}_{34}O$, which reacts with acetic anhydride to give an ester.
(b) Bombykol also reacts with acetic anhydride to give another ester, which on oxidation ozonolysis $\left(O_3/H_2{O}_2\right)$ gives a mixture of butanoic acid, oxalic acid, and 10-hydroxy decanoic acid.
Determine the number of double bonds in bombykol. Write the structures of compound $\left(A\right)$ and bombykol. How many geometrical isomers are possible of bombykol?

Q. In the given $S_{N}2$ reaction, _______will get substituted.

1. $I{\left(C{H}_2\right)}_3{O}^{-}$
2. bromide
3. $BrC{H}_2{O}^{-}$
4. iodide

Q.

Given:

The enthalpy of hydrogenation of these compounds will be in the order as:

1. II > III > I

2. II > I > III

3. I > II > III

4. III > II > I

Q. Answer the following:
How does $SiC{l}_4$ differ from $CC{l}_4$?

Q. Name a group of organic compounds that can be hydrogenated. With the help of a suitable example explain the process of hydrogenation along with the conditions that are required for it. Name any natural organic compound that is hydrogenated.

Q. 2 bromobutane+ alc KOH minor and major product

Q. Which of the following orders is correct for heat of hydrogenation of these compounds?

1. $III>II>I$
2. $II>III>I$
3. $III>I>II$
4. $I>II>III$