Урівняти c2h6 + br = c2h5br + hbr c4h19 + cl = c4h10cl2 + hcl

первая 
1) CaC2 + 2H2O = Ca(OH)2 + C2H2 
2) C2H2 + H2O = CH3CHO 
CH3CHO + H2 = CH3CH2OH 
3)CH3CH2OH + CuO = CH3CHO + Cu + H2O 
СH3CHO + Ag2O = CH3COOH + 2Ag 
вторая 
1) С + 2H2 = CH4 
2)CH4 + CL2 = CH3CL + HCL 
3) 2CH3CL + 2Na = C2H6 + 2NaCL 
C2H6 = C2H4 + H2 
третья 
1) С2H4 + HBr = C2H5Br 
2) C2H5Br + NaOH = C2H5OH + NaBr 
3) C2H5OH + CH3COOH = CH3COOC2H5 
четвертая 
1) CH3COOH + H2 = CH3CHO + H2O 
2) СH3CHO + Ag2O = CH3COOH + 2Ag 
3) CH3COOH + NaOH = CH3COONa + H2O 
пятая 
1) C2H2 + H2O = CH3CHO 
2) CH3CHO + Ag2O = CH3COOH + 2Ag 
3) CH3COOH + C3H7OH = CH3COOC3H7 + H2O
вроде так