electrolysis of aqueous solutions

the products of electrolysis depends on how reactive the elements involved are

at the - electrode if metal ions/H+ ions are present the metal ions will stay in solution if the metal is more reactive than hydrogen

hydrogen will be produced unless the metal is less reactive than it

at the + electrode if OH-/halide ions(Cl-,Br-,I-) are present then molecules of chlorine,bromine,iodine will be formed. 

if no halide is present then the OH- ions are discharged and…