In its reaction with silver nitrate,acetylene shows:

Propyne on cyclic polymerisation gives

Propyne reacts with excess $HBr$ to form the compound $Z$. The structure of $Z$ is:

The product $(C)$ of the above reaction is:
Maleic anhydride $\xrightarrow{H_3O^+}$ $(A)$ $\xrightarrow{NaOH}$ $(B)$ $\xrightarrow{\text{Kolbe electrolysis}}$ $(C)$

Choose the correct set of reagents for the following conversion:
$trans-(Ph-CH=CH-CH_3) \rightarrow cis-(Ph-CH=CH-CH_3)$

Write the following reactions:
$(1)$ Ethyne $+$ $(Cl_2 \text{ or } Br_2)$
$(2)$ Hydration reaction of but$-1-$yne.