Ответ:
а)CH3-CH3->CH2=CH2+H2(условие Cr2O3, t)
CH2=CH2+H2O->CH3-CH2OH
5C2H5OH+4KMnO4+6H2SO4->5CH3COOH+11H2O+2K2SO4+4MnSO4
б)CaC2+2H2O->C2H2+Ca(OH)2
C2H2+H2->C2H4
CH2=CH2+H2O->CH3-CH2OH
5C2H5OH+4KMnO4+6H2SO4->5CH3COOH+11H2O+2K2SO4+4MnSO4
CH3COOH+C2H5OH->CH3-COO-C2H5+H2O