The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapor in the vapor phase. A suitable method for the extraction of these oils from the flowers is

1.  Distillation

2.  Crystallisation

3.  Distillation under pressure

4.  Steam distillation

During the hearing of a court case, the judge suspected that some changes in the documents had been carried out. He asked the forensic department to check the ink used at two different places. The technique that can give the best results is-

1. Column chromatography

2. Solvent extraction

3. Distillation

4. Thin layer chromatography

The principle involved in paper chromatography is

1. Adsorption

2. Partition

3. Solubility 

4. Volatility

The correct order of decreasing stability of the following cations is -

$$\begin{gathered} \underset{\left(\mathrm{I}\right)}{{\mathrm{CH}}_3-\stackrel{\oplus }{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_{3 }} \\ \underset{\left(\mathrm{II}\right)}{{\mathrm{CH}}_3-\stackrel{\oplus }{\mathrm{C}}\mathrm{H}-{\mathrm{OCH}}_3} \\ \underset{\left(\mathrm{III}\right)}{{\mathrm{CH}}_3-\stackrel{\oplus }{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_2-{\mathrm{OCH}}_3} \end{gathered}$$

1. II>I>III

2. I>II>III

3. II<I<III

4. I<II<III

 The correct IUPAC name for  is _____.

1. 2-Ethyl-3-methylpentane

2. 3,4-Dimethylhexane

3. 2-sec-Butylbutane

4. 2,3-Dimethylbutane

Which of the following carbon marked with asterisk is expected to have greatest positive charge?

1. $*{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Cl}$

2. $*{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{Mg}}^{+}{\mathrm{Cl}}^{-}$

3. $*{\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{Br}$

4. $*{\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

The most stable carboxylate ion among the following is-

1. ${\mathrm{CH}}_3-\stackrel{\mathrm{O}}{\stackrel{\left|\right|}{\mathrm{C}}}-{\mathrm{O}}^{-}$

2. $\mathrm{Cl}-{\mathrm{CH}}_2-\stackrel{\mathrm{O}}{\stackrel{\left|\right|}{\mathrm{C}}}-{\mathrm{O}}^{-}$

3. $\mathrm{F}-{\mathrm{CH}}_2-\stackrel{\mathrm{O}}{\stackrel{\left|\right|}{\mathrm{C}}}-{\mathrm{O}}^{-}$

4. ${\left(\mathrm{F}\right)}_2-\mathrm{CH}-\stackrel{\mathrm{O}}{\stackrel{\left|\right|}{\mathrm{C}}}-{\mathrm{O}}^{-}$

Electrophilic addition reactions proceed in two steps. The first step involves the addition of an electrophile. The major intermediate formed in the first step is -

${\mathrm{H}}_3\mathrm{C}-\mathrm{HC}={\mathrm{CH}}_2+{\mathrm{H}}^{+}\to$?

1. $2°$ carbanion

2. $1°$ carbocation

3. $2°$ carbocation

4. $1°$ carbanion

Covalent bonds can undergo fission in two different ways. The correct representation involving heterolytic fission of ${\mathrm{CH}}_3-\mathrm{Br}$ is

1. 

2. 

3.  

4.

The addition of HCl to an alkene proceeds in two steps. The first step is the attack of H⁺ ion on the double bond portion. The same can be shown as -

1.    

2.  

3.   

4.  All of these are possible