Aromatization

Q. The product obtained when n-heptane is heated to a temperature of about 773 K under high pressure in the presence of $C{r}_2{O}_3/A{l}_2{O}_3$ catalyst is:

1. 1, 2-dimethylbenzene
2. Ethylbenzene
3. Benzene
4. Toluene

Q. n-heptane when heated to a temperature of about 773 K under high pressure in the presence of $C{r}_2{O}_3/A{l}_2{O}_3$ catalyst gives -

1. Ethylbenzene
2. 1, 2-dimethylbenzene
3. Benzene
4. Methylbenzene(Toluene)

Q.

n- Octane in the presence of Cr₂O₃/Al₂O₃ at 873K changes to

1. 1, 2-Dimethylcyclohexane

2. 1, 2 - Dimethylcyclohex-1-ene

3. 1, 2- Dimethylcyclohexa-1, 3-diene

4. O-xylene

Q. On reaction with benzene, which halide is least reactive for Friedel crafts reaction?

1. Isopropyl chloride
2. Vinyl chloride
3. Methyl chloride
4. Allyl chloride

Q.
Number of oxygen atom present in the aromatic product P is:

Q. Which of these species is anti-aromatic?

1. I only
2. II only
3. III only
4. both II and III

Q. Which of the following heterocyclic compounds would have aromatic character?

1. 
2. 
3. 
4. 

Q. Name the hydrocarbon which when heated to a temperature of about 773 K under high pressure in the presence of $C{r}_2{O}_3/A{l}_2{O}_3$ catalyst gives benzene.

1. n-pentane
2. n-pentane
3. n-hexane
4. n-octane

Q. Which of the following is the smallest aromatic species?

1. Cyclopropene
2. Cyclopropenyl cation
3. Cyclopropenyl anion
4. Cyclobutadiene

Q.
How many of these are anti-aromatic in nature?

Q.

Ethene can be prepared by the reaction of ethanol with

1. Hot conc. ${\mathrm{H}}_2{\mathrm{SO}}_4$

2. Alkaline ${\mathrm{KMnO}}_4$

3. Sodium metal

4. ${\mathrm{NaHCO}}_3$

Q. 40. Which would not react with benzene sulphonyl chloride in aqueous NaOH? Aniline, N, N-dimethylaniline, p-toluidine, N-ethyl aniline

Q. Tropylium carbanion and cyclo penta dienyl carbanion is non aromatic or antiaromatic ?

Q. Which of the following is the smallest aromatic species?

1. Cyclopropene
2. Cyclopropenyl cation
3. Cyclopropenyl anion
4. Cyclobutadiene

Q. Ten millilitres of a gaseous hydrocarbon was exploded with oxygen. After the explosion, there was a contraction of 20 ml in volume. On shaking the residual gaseous mixture with KOH, there was a further concentration of 20 ml in volume. Molecular formula is $C_x{H}_y$. All the volumes were recorded at the same temperature and pressure. Here $\text{x+y}$ is:

Q. Assertion :The $p{K}_a$ value of (I) is lower than the $p{K}_a$ value of (II). Reason: Non-aromatic compounds are more stable than anti-aromatic compounds.

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. Assertion is incorrect but Reason is correct

Q. n-heptane when heated to a temperature of about 773 K under high pressure in the presence of $C{r}_2{O}_3/A{l}_2{O}_3$ catalyst gives -

1. Ethylbenzene
2. 1, 2-dimethylbenzene
3. Benzene
4. Methylbenzene(Toluene)

Q. why aromatic aldehydes do not show nucliophilic addition reaction ?

Q. Write the structure of the following alkane.
$3-Ethyl-2-methylpent-2-ene$

Q.

Ethanol reacts with sodium and forms two products. These products are

1. Sodium hydroxide and hydrogen gas

2. Sodium ethanoate and ethanoic acid

3. Sodium ethanoate and hydrogen gas

4. Sodium hydroxide and ethanoic acid

Q. Grignard reagent behaves as _______.

1. Strong acid
2. Strong base
3. Neutral
4. None of thses

Q. In aromatization of n-hexane, the catalyst used is:

1. $C{r}_2{O}_3$
2. All
3. $M{o}_2{O}_3$
4. $V_2{O}_5$

Q. Benzyne is:

1. aromatic
2. non-aromatic
3. antiaromatic
4. all of the above

Q. n-heptane when heated to a temperature of about 773 K under high pressure in the presence of $C{r}_2{O}_3/A{l}_2{O}_3$ catalyst gives -

1. Ethylbenzene
2. 1, 2-dimethylbenzene
3. Benzene
4. Methylbenzene(Toluene)

Q. Which aromatic compound is obtained when n-octane undergoes catalytic hydroforming?

1. ethylbenzene
2. m-xylene
3. o-xylene
4. p-xylene

Q. Aromatisation of n-heptane by passing over $(A{l}_2{O}_3+C{r}_2{O}_3)$ catalyst at $773K$ gives :

1. Benzene
2. Toluene
3. Mixture of both
4. Heptylene

Q.

n- Octane in the presence of Cr₂O₃/Al₂O₃ at 873K changes to

1. O-xylene

2. 1, 2 - Dimethylcyclohex-1-ene

3. 1, 2- Dimethylcyclohexa-1, 3-diene

4. 1, 2-Dimethylcyclohexane

Q. Catalytic dehydrogenation of n-haptane in presence of $C{r}_2{O}_3/A{l}_2{O}_3$ at $750K$ gives :

1. iso-heptane
2. $1$-heptene
3. toluene
4. $2,3$-dimethylpent-$1$-ene

Q. Fill in the blanks in the following:
The conversion of n-hexane into benzene in presence of a catalyst $C{r}_2{O}_3$ at ${600}^{\circ }C$ is termed .....

Q.
Number of oxygen atom present in the aromatic product P is: