Explanation:
Balanced chemical reaction equation will be as follows.

In human body, the neutral iron changes into
(aq) cation. There will be an oxidation-half reaction and a reduction-half reaction. Equations for this reaction are as follows.
Oxidation: 2Fe^{2+}(aq) \rightleftharpoons 2Fe^{3+}(aq) + 2e^{-}[/tex] .... (1)
Reduction:
...... (2)
On adding both equation (1) and (2), the overall reaction equation will be as follows.

Therefore, neutral iron is a part of Heme - b group of Hemoglobin and in an aqueous solution it dissolutes as a part of Heme group. Hence, then it becomes an
cation.
Answer:
9.28
Explanation:
pOH refers to a measure of hydroxide ions concentration. pOH tells about the alkalinity of a solution. If pOH is less than 7 then aqueous solutions are alkaline, acidic if pOH is greater than 7 and neutral if pOH is equal to 7.
Concentration of the hydroxide ions = 1.9 x 10-5 M
pH = 
pOH = 14 - pH
=14 - 4.72 = 9.28