Write half-reactions for the oxidation and reduction process for each of the following.
a. fe2+ + mno4 - fe3+ + mn2+
b. sn2+ + io3 - sn4+ + i-
c. s2- + no3 - s + no
d. nh3 + no2 n2 + h2o

a) ⇒

    + 2 + 3⇒

b) ⇒

   ⇒

   ⇒

c)⇒

  ⇒

d) ⇒

   ⇒

Explanation:

a) ⇒

    + 2 + 3⇒ half reaction suggest that you need water to reaction occurs.

b) ⇒

   ⇒

   ⇒ half reaction suggest that you need acid to reaction acurrs.

c)⇒

  ⇒

d) ⇒

   ⇒ note that you can obtain the total reaction by miltiplying first half reaction by 4 and second half reaction by 3.