What is the role of metal or reagents written on arrows in the given chemical reactions? \[\begin{array}{cc}\ce{CH3}\phantom{.....}\ce{CH3}\phantom{.........}\ce{CH3}\phantom{..}\ce{CH3}\phantom{..........}\\\phantom{...}\backslash\phantom{......}/\phantom{................}|\phantom{.....}|\phantom{............}\\\ce{C} = \ce{C} + \ce{H2} \overset{\ce{Ni}}{\rightarrow} \ce{CH3 - C - C - CH3}\\\phantom{.}/\phantom{........}\backslash\phantom{..............}|\phantom{....}|\phantom{.........}\\\ce{CH3}\phantom{....}\ce{CH3}\phantom{............}\ce{H}\phantom{...}\ce{H}\phantom{........}\end{array}\] \[\ce{CH3COOH + CH3CH2OH \overset{\ce{Conc. H2SO4}}{\rightarrow}CH3COOC2H5 + H2O}\] \[\ce{CH3CH2OH}\ce{->[Alk.KMnO4][Heat]CH3COOH}\]

This reaction represents hydrogenation of unsaturated hydrocarbons. Nickel acts as a catalyst in this reaction. This is esterification reaction. Concentrated sulphuric acid acts as a catalyst as well as dehydrating agent in this reaction. In this reaction, alkaline potassium permanganate is adding oxygen to alcohol. Hence, it acts as an oxidising agent.

What is the role of metal or reagents written on arrows in the given chemical reactions? CHX3.....CHX3.........CHX3..CHX3.............∖....../................|.....|........... - Science

Question

What is the role of metal or reagents written on arrows in the given chemical reactions?

$\begin{array}{cc} CH_{3} CH_{3} CH_{3} CH_{3} \\ ∖ / | | \\ C = C + H_{2} \overset{Ni}{\to} CH_{3} - C - C - CH_{3} \\ / ∖ | | \\ CH_{3} CH_{3} H H \end{array}$
$CH_{3} COOH + CH_{3} CH_{2} OH \overset{Conc \cdot H_{2} SO_{4}}{\to} CH_{3} COOC_{2} H_{5} + H_{2} O$
$CH_{3} CH_{2} OH \to_{Heat}^{Alk \cdot KMnO_{4}} CH_{3} COOH$

Answer in Brief

Solution

This reaction represents hydrogenation of unsaturated hydrocarbons. Nickel acts as a catalyst in this reaction.
This is esterification reaction. Concentrated sulphuric acid acts as a catalyst as well as dehydrating agent in this reaction.
In this reaction, alkaline potassium permanganate is adding oxygen to alcohol. Hence, it acts as an oxidising agent.