Write redox couples involved in the reactions (i) to (iv) given in question 34.
Redox couple is a reducing element along with its oxidizing form. So for the given example,
(i) Cu2+ /Cu and Zn2+/Zn
(ii) Mg+/Mg and Fe2+/Fe
(iii) Br-/Br and Cl-/Cl
(iv) Fe2+ /Fe and Cd2+/Cd