How will you convert :
(a) Ethane to butane (b) Ethyne to methane
(c) Ethene to ethyne (d) Methane to ethane
(e) Propene to 2, 3-dimethylbutane (f) Ethane to ethyne
(g) Ethyne to but-2-yne

Explanation

(a) `underset("Ethane")(CH_(3)CH_(3)) underset("Sunlight")overset(Cl_(2))to underset("Ethyl chloride")(CH_(3)CH_(2)Cl) underset("Wurtz reaction")overset("2Na, ether")to underset("Butane")(CH_(3)CH_(2)CH_(2)CH_(3))`
(b) Ethyne to methane
`HC -=CH underset(HgSO_(4))overset(H^(+), H_(2)O)to CH_(3)CHO underset(K_(2),Cr_(2)O_(7),H^(+))overset([O])to CH_(3)COOH overset("NaOH")to CH_(3)COONa overset("NaOH,CaO")to underset("Methane")CH_(4)`
(c) Ethene to ethyne
`underset("Ethene")(H_(2)C =CH_(2)) underset(C CI_(4))overset(Br_(2))to underset(Br)underset(|)CH_(2)-underset(Br)underset(|)CH_(2) overset("2alc. KOH")to underset("Ethyne")(CH- =CH)`
(d) Methane to ethane
`underset("Methane")(CH_(4)) underset("Sunlight")overset(Cl_(2))to CH_(3)Cl underset("Wurtz reaction")overset("Na, ether")to underset("Ethane")CH_(3)CH_(3)`
(e) Propene to 2, 3-dimethylbutane
`CH_(3)CH= CH_(2) overset(HBr)to CH_(3)underset(Br)underset(|)CHCH_(3) underset("Wurtz reaction")overset("Na, ether")to underset("2, 3-Dimethylbutane")(CH_(3) underset(CH_(3))underset(|)CH- underset(CH_(3))underset(|)CH-CH_(3))`
(f) Ethane to ethyne
`underset("Ethane")(CH_(3)CH_(3)) underset("Sunlight")overset(Cl_(2))to CH_(3)CH_(2)Cl overset("alc. KOH")to CH_(2)= CH_(2) overset(Br_(2))to underset(Br) underset(|)CH_3-underset({:(" "darr 2KOH("alc.")),(" "HC-=CH),(" Ethyne"):})(underset(Br)underset(|)CH_2)`
(g) Ethyne to but-2-yne
`underset("Ethyne")(HC -= CH) overset(2NaNH_(2)) to underset("Disodium acetylide")(NaC -=CNa) overset(2CH_(3) Br) to underset("But-2-yne")(CH_(3)C -=C CH_(3))`