Introduction to Aromatic Compounds

Q.

What are masking and demasking agents in analytical chemistry?

Q. Dow's process is used for the preparation of which of the following?

1. Alkane
2. Alkylhalide
3. Phenol
4. Alcohol

Q.

How is Benzene diazonium chloride converted to Benzene?

1. 

2. 

3. 

4. Both (b) & (c)

Q. What is principle of chromatography?

Q. Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromine which by wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is

1. $C{H}_2=C{H}_2$
2. $C{H}_4$
3. $C{H}_3-C{H}_3$
4. $CH\equiv CH$

Q. The substance which can be used as adsorbent in column chromatography is:

1. $N{a}_{2}S{O}_4$
2. $N{a}_{2}O$
3. NaCl
4. $A{l}_2{O}_3$

Q. A violet colour with sodium nitroprusside in the test of sulphur in an organic compound is due to the formation of:

1. $N{a}_4\left[Fe\right(CN{)}_{6}NO]$
2. $N{a}_4\left[Fe\right(CN{)}_{5}NOS]$
3. $N{a}_3\left[Fe\right(CN{)}_{5}NS]$
4. $F{e}_4\left[Fe\right(CN{)}_6{]}_3$

Q.

How do you count pi electrons in aromatic compounds?

Q. An aromatic compounds among other things should have a $(4n+2)$ $\pi -$ electron cloud containing $(4n+2)$electrons, where $n$ can't be :

1. $\frac{1}{2}$
2. $3$
3. $2$
4. $1$

Q. The correct statement(s) concerning conformers of 1, 2-dichloroethane is/are

1. Its gauche form has higher potential energy than eclipsed conformer
2. Anti form is more stable than gauche form
3. Dipole moment of anti-form is non-zero
4. Dipole moment of gauche form is non-zero

Q.

Differentiate between the principle of estimation of nitrogen in an organic compound by
(i) Dumas method and (ii) Kjeldahl’s method.

Q. 59 Explain the mechanism of azo coupling reaction between aniline and benzene diazonium salt and the major product.

Q. In column chromatography, the moving phase is?

1. the substances which are to be separated
2. Eluent
3. Adsorbent
4. Mixture of eluent and substances to be separated

Q.

Give an example of a radical which is trivalent?

Q. During halogen test, sodium fusion extract is boiled with concentrated $HN{O}_3$ to

Q.

An organic compound $“\mathrm{A}”$ on treatment with $\mathrm{benzene}\mathrm{sulphonyl}\mathrm{chloride}$gives compound $\mathrm{B}.\mathrm{B}$ is soluble in $\mathrm{dil}.\mathrm{NaOH}$ solution. Compound $\mathrm{A}$ is:

1. ${\mathrm{C}}_6{\mathrm{H}}_5-\mathrm{N}-{\left({\mathrm{CH}}_3\right)}_2$

2. ${\mathrm{C}}_6{\mathrm{H}}_5-{\mathrm{NHCH}}_2{\mathrm{CH}}_3$

3. 

4. ${\mathrm{C}}_6{\mathrm{H}}_5-{\mathrm{CH}}_2{\mathrm{NHCH}}_3$

Q. An alkyl halide by the formation of its Grignard reagent and heating with water gives propane. What is the original alkyl halide?

1. Methyl iodide
2. Ethyl iodide
3. Ethyl bromide
4. Propyl bromide

Q. In lead acetate test of sulphur detection, Lassaigne extract is acidified with ______ and then lead acetate solution is added.

1. Oxalic acid
2. Hydrochloric acid
3. Sulphuric acid
4. Acetic acid

Q. Identify the correct statement which is related to aromatic hydrocarbon

1. It has only sigma bonds
2. It has only pi bonds
3. It has sigma and two pi bonds
4. It has sigma and delocalized pi bond

Q. n-Heptane when passing over $(A{l}_2{O}_3+C{r}_2{O}_3)$ catalyst at $773\text{K}$ gives:

1. Benzene
2. Toluene
3. Benzaldehyde
4. 1-Heptene

Q. Which is the correct sequence of reactions for preparation of m-bromoaniline from benzene?

1. $B{r}_2,FeB{r}_3\to Fe,HCl\to HN{O}_3,H_{2}S{O}_4$
2. $B{r}_2,FeB{r}_3\to HN{O}_3,H_{2}S{O}_4\to Fe,HCl$
3. $HN{O}_3,H_{2}S{O}_4\to B{r}_2,FeB{r}_3\to Fe,HCl$
4. $HN{O}_3,H_{2}S{O}_4\to Fe,HCl\to B{r}_2,FeB{r}_3$

Q. Choose the correct statement(s):

1. Anti-aromatic compounds are more stable than aromatic compounds.
2. Anti-aromatic compounds have more electrons in bonding molecular orbitals.
3. Aromatic compounds have more electrons in bonding molecular orbitals.
4. Non-aromatic compounds are more stable than anti-aromatic compounds.

Q. The fusion of an organic compound with solid sodium metal is undertaken for testing nitrogen, sulphur and halogens. This test is called:

1. Dumas method
2. Carius method
3. Lassaigne's test
4. Kjeldahl's method

Q. Lassaigne's test for the detection of nitrogen will fail in the case of:

1. $N{H}_{2}CON{H}_2$
2. $C_6{H}_{5}NHN{H}_2.2HCl$
3. $N{H}_{2}CON{H}_{2}HCl$
4. $N{H}_{2}N{H}_2$

Q.

Carbon, the Group (14) element in the Periodic Table, is known to form compounds with many elements. Write an example of a compound formed with

(a) chlorine (Group 17 of Periodic Table)

(b) oxygen (Group 16 of Periodic Table)

Q. Prussian blue colour is obtained by mixing together an aqueous solution of $F{e}^{3+}$ salt with:

1. Ferrocyanide
2. Hydrogen cyanide
3. Ferricyanide
4. Sodium cyanide

Q. Which of the following show strongest -I effect
a)^{+N(CH_{​​​​​3})₃
b) +NH_{​​​​​3}
c) +S(CH_{​​​​​3})₃
d) F}

Q. Mechanism for preparation of alkene from vicinal dihalide

Q. In Kjeldahl method , nitrogen in the compound on heating with concentrated sulphuric acid and copper sulphate gets converted to ____

1. $(N{H}_4{)}_{2}S{O}_4$
2. $N{O}_2$
3. $N{H}_3$
4. None of the above

Q.

What are alkyl, aryl, aliphatic and aromatic groups?