The product $(P)$ in the reaction is:

$1, 2-$dibromocyclooctane $\xrightarrow[\substack{\text{(ii) } NaNH_2 \\ \text{(iii) } Hg^{2+} / H^{+} \\ \text{(iv) } Zn-Hg / H^{+}}]{\text{(i) } KOH \text{ (alc.) }} \underset{\text{(Major product)}}{P}$. $P$ is

The number of isomeric tetraenes ($NOT$ containing $sp$-hybridized carbon atoms) that can be formed from the following reaction sequence is.....

Product $(C)$ is

Give distinguishing tests for the following:
$(a)$ Ethane and ethyne (Alkane and Alkyne $RC \equiv CH$)
$(b)$ Ethene and Ethyne (Alkene and Alkyne $RC \equiv CH$)
$(c)$ Dimethyl ethyne and ethyne
$(d)$ Ethane and Ethene (Alkane and alkene)

How many $\sigma$ and $\pi$ bonds are present in the following?
$(a)$ $But-1-ene-3-yne$
$(b)$ $Buta-1,3-diene$
$(c)$ $CH_2=CH-C\equiv N$
$(d)$ $Propa-1,2-diene$
$(e)$ $1-butyne$ and $2-butane$