What is formed when acetylene reacts with alkaline $KMnO_4$?

The reagent used to convert an alkyne to an alkene is:

The reaction of $1,2-$dibromoethane with alcoholic $KOH$ yields product $X$. What is the hybridization of the carbon atoms in $X$?

Which is the most suitable reagent among the following to distinguish compound $(3)$ from the rest of the compounds?
$1. CH_3-C \equiv C-CH_3$
$2. CH_3-CH_2-CH_2-CH_3$
$3. CH_3-CH_2-C \equiv CH$
$4. CH_3-CH=CH_2$

Identify $Z$ in the following sequence:
$C_3H_7OH$ $\xrightarrow{H_2SO_4} X$ $\xrightarrow{Br_2} Y$ $\xrightarrow{KOH} Z$

When acetylene is passed through a solution of dilute sulfuric acid containing mercuric sulfate,the number of $\pi$ bonds in the final product obtained is.........