What happens when
$\left(\mathrm{i}\right)$ Ethyl chloride is treated with $\mathrm{NaI}$ in the presence of acetone.
$\left(\mathrm{ii}\right)$ Chlorobenzene is treated with $\mathrm{Na}$ metal in the presence of dry ether.
$\left(\mathrm{iii}\right)$ Methyl chloride is treated with ${\mathrm{KNO}}_2$? Write chemical equations in support of your answer.

How would you convert the following compound into benzene?

Ethyne.

How would you convert the following compound into benzene?

Ethene.

Write the number of $\mathrm{\sigma }$ and $\mathrm{\pi }$ bonds in the following molecules?

$\left(\mathrm{a}\right)$ 

$\left(\mathrm{b}\right)$ 

$\left(\mathrm{c}\right)$ 

Find the number of $1°, 2°$ and $3°$ hydrogen atoms in the following compounds.

$\left(\mathrm{a}\right)$ 

$\left(\mathrm{b}\right) {\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

$\left(\mathrm{c}\right)$ ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2-{\mathrm{CH}}_3$

Find the hybridization state of each carbon atoms in following compound?

${\mathrm{CH}}_2=\mathrm{C}=\mathrm{CH}-{\mathrm{CH}}_2-\mathrm{C}\equiv \mathrm{C}-{\mathrm{CH}}_2-{\mathrm{NH}}_2$

Expand each the following condensed formulae into their complete structural and bond line formula:

$\left(1\right)$ ${\mathrm{HOCH}}_2{\mathrm{CH}}_2{\mathrm{NH}}_2$

$\left(2\right)$ ${\mathrm{CH}}_3{\left({\mathrm{CH}}_2\right)}_3\mathrm{OH}$

$\left(3\right)$ ${\mathrm{CH}}_3{\mathrm{CH}}_2{\mathrm{COCH}}_2{\mathrm{CH}}_3$

$\left(4\right)$ ${\mathrm{CH}}_3\mathrm{CH}=\mathrm{CH}{\left({\mathrm{CH}}_2\right)}_3{\mathrm{CH}}_3$

Find $\mathrm{DU}$ of following compound:

$\left(\mathrm{a}\right)$ ${\mathrm{C}}_5{\mathrm{H}}_{10}$

$\left(\mathrm{b}\right)$