20.14.
CH2=CH2 +HCl=> CH3-CH2Cl+KOH(spirt)=> CH2=CH2 + KCl +H2O
CH2=CH2+ Br2=>CH2Br-CH2Br
20.15.
CH3-CHOH-CH3(H2SO4)=>CH3-CH=CH2 + H2O
CH3-CH=CH2+HCl=>CH3-CHCl-CH3
CH3-CHCl-CH3 + NaOH(spirt)=>CH3-CH=CH2+NaCl+H2O
CH3-CH=CH2+HBr=>CH3-CHBr-CH3
CH3-CHBr-CH3+2Na=>CH3-CH(CH3)-CH(CH3)-CH3 + 2NaBr