In kolbeys electrolysis sodium salt of carboxilic acid is electrolysed to give ethane at anode and hydrogen at cathode.CH3COONA+HOH. + =CH3-CH3+2CO2+2NaOH +H2 CH3COONa+HOH. here both CH3 combine to give ethane,both coo combine to give 2CO2 ,2 sidium from carboxilic acid and 2 OH from water combine to form 2NaOH and two h combine to give H2 .