Why are acetylenic hydrogens acidic?

1. The sigma electron density of the C-H bond in acetylene is closer to carbon, which has 50% s-character.

2. Acetylene has only one hydrogen on each carbon.

3. Acetylene contains the least number of hydrogens among the possible hydrocarbons having two carbons.

4. Acetylene belongs to the class of alkynes with the molecular formula ${\mathrm{C}}_{\mathrm{n}}{\mathrm{H}}_{2\mathrm{n}-\mathrm{2 }}$

A compound is treated with ${\mathrm{NaNH}}_2$ to give sodium salt. Identify the compound.

1. ${\mathrm{C}}_2{\mathrm{H}}_2$ 

2. ${\mathrm{C}}_6{\mathrm{H}}_6$

3. ${\mathrm{C}}_2{\mathrm{H}}_6$ 

4. ${\mathrm{C}}_2{\mathrm{H}}_4$

Which alkene on ozonolysis gives ${}_{}$
 \(CH_3CH_2CHO\) and  \(CH_3CCH_3\\ ~~~~~~~~||\\ ~~~~~~~~O\) 

1.

2. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}={\mathrm{CHCH}}_2{\mathrm{CH}}_3$

3. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{CH}={\mathrm{CHCH}}_3$

4. 

Hydroxylation of propyne in the presence of ${\mathrm{HgSO}}_4/{\mathrm{H}}_2{\mathrm{SO}}_4$ is initiated by the attack of:

1. carbene 

2. free radical

3. electrophile

4. nucleophile

Which products are obtained from the ozonolysis of buta-1,3-diene?

1. Formaldehyde and glyoxal  
2. Acetaldehyde and glyoxal  
3. Carbon dioxide and glyoxal  
4. Formaldehyde, glyoxal, and acetaldehyde

Which is the most suitable reagent among the following to distinguish compound (III) from rest of the compounds?

I. ${\mathrm{CH}}_3-\mathrm{C}\equiv \mathrm{C}-{\mathrm{CH}}_3$

II. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

III. ${\mathrm{CH}}_3-{\mathrm{CH}}_2-\mathrm{C}\equiv \mathrm{CH}$

IV. ${\mathrm{CH}}_3-\mathrm{CH}={\mathrm{CH}}_2$

The reaction, 

${\mathrm{C}}_6{\mathrm{H}}_6$ + ${\mathrm{CH}}_3\mathrm{Cl}\underset{{\mathrm{AlCl}}_3}{\overset{\mathrm{Anhydrous}}{\to }}$${\mathrm{C}}_6{\mathrm{H}}_5{\mathrm{CH}}_3$ + HCl

is an example of:

1. Friedel-Crafts reaction

2. Kolbe's synthesis

3. Wurtz's reaction

4. Grignard synthesis

2-Methylpropene and But-1-ene can be distinguished by:

1. Baeyer's reagent

2. Ammoniacal ${\mathrm{AgNO}}_3$

3. ${\mathrm{Br}}_2$ solution 

4. ${\mathrm{O}}_3$, $\mathrm{Zn}/{\mathrm{H}}_2\mathrm{O}$

Nitration of benzene is:

1. nucleophilic substitution

2. electrophilic substitution

3. electrophilic addition

4. nucleophilic addition

Which of the following compounds has the lowest boiling point?

1. ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_2{\mathrm{CH}}_3$

2. ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_2{\mathrm{CH}}_3$

3. ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{CH}-\mathrm{CH}={\mathrm{CH}}_2$

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