Объяснение:
1) CH2=CH2+H2-> CH3-CH3 (t,kat)
2) CH3-CH3+Cl2->CH3-CH2-Cl+HCl(hv)
3) C2H5Cl+NaOH->C2H5OH+NaCl
4) C2H5OH+3O2-> 2CO2+3H2O
