LIST-I(Conversion)	LIST-2(process involved)
A) Benzene $\to$Cyclohexane	1) Hydration
B) Ethylene $\to$Formaldehyde	2) Controlled hydrogenation
C) Acetylene $\to$Ethylene	3) Hydrogenation
D) Benzene $\to$Toluene	4) Ozonolysis
	5) Alkylation

(A) -------3

Benzene to cyclo hexane is a reaction of Benzene with Hydrogen in presence of Ni catalyst so it is hydrogination process.

(B) -------4

 Ethylene to Formaldehyde is a reaction of Ethylene treated with Ozone to give Ethylene ozonoid & on hydrolysis of water in presence of Water to give  Formaldehyde so it is Ozonolysis

(c)------2

 Acetylene to Ethylene is a reaction of ethyne in the presence of Lindlar catalyst gives Ethylene  so it is  Controlled hydrogenation

(D) -------5

 Benzene to Toluene is a reaction of benzene with methyl chloride in the presence of aluminium chloride (Lewis acid) to give toluene.so it is Friedal craft's Alkylation.