a/1) CaCO3 --to--> CaO + CO2
2) CaO + 3C --to cao--> CaC2 + CO
3) CaC2 + 2H2O = Ca(OH)2 + C2H2
4) C2H2 + H2 --- pd, to----> C2H4
5) nCH2=CH2 --xt,to---> (-CH2-CH2-)n
6) C2H5OH ---H2SO4 đặc, 170oC ---> C2H4 + H2O
7) C2H4 + H2O ----H2SO4 loãng, to---> C2H5OH
8) C2H2 + HCl ----HgCl2, p, to ---> C2H3Cl
9) nCH2=CH(Cl) ---xt,to---> (-CH2-CH(Cl)-)n () là mạch nhánh nhé!

b/1.Al4C3 + 12HCl = 4AlCl3 + 3CH4
2/2CH4 ---1500oC, làm lạnh nhanh ---> C2H2 + 3H2
3/ C2H2 + H2 --- pd, to----> C2H4
4/ C2H4 + H2 --ni,to--->C2H6
5/ C2H6 + Cl2 ---1:1,as---> C2H5Cl + HCl
6/ C2H2 + 2H2 --ni.to---> C2H6
7/ C2H4 + Br2 = C2H4Br2
8/ C2H2 + Br2 (1:1) = C2H2Br2
9/ C2H2Br2 + Br2 = C2H2Br4
10/ C2H4 + HCl = C2H5Cl