C2h4-c2h5cl-c2h5oh-c2h5-o-c2h5-co2-caco3
CH2=CH2+HCl = CH3CH2Cl CH3CH2Cl+NaOH = CH3CH2OH+NaCl 2CH3CH2OH = CH3CH2OCH2CH3+H2O CH3CH2OCH2CH3+6O2 = 4CO2+5H2O CO2+CaO=CaCO3