Answer:
I want to say (A) but i also want to say (C) but i can be wrong. most likely (C)
Explanation:
hope this helps lol and have a great day
<u>Answer:</u>
<em>A. 10.25</em>
<em></em>
<u>Explanation:</u>
Pkb =4.77
So pka = 14 - pka = 9.23


Initial 0.50M 0 0
Change -x +x +x
Equilibrium 0.50M-x +x +x


(-x is neglected) so we get

![pH=-log[H^3 O^+]\\\\pH=-log[1.72\times10^{-5}]\\\\pH=4.76](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E3%20O%5E%2B%5D%5C%5C%5C%5CpH%3D-log%5B1.72%5Ctimes10%5E%7B-5%7D%5D%5C%5C%5C%5CpH%3D4.76)
pOH = 14 - pH
= 14 - 4.76
pOH = 9.24 is the answer
Option A - 10.25 is the answer which is close to 9.24
Equation is as follow,
Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
Oxidation:
3 CO → 3 CO₂
Oxidation state of C in CO is +2, and that in CO₂ is +4. So, carbon has lost 2 electrons per mole and 6 electrons per 3 moles hence,
3 CO → 3 CO₂ + 6 e⁻
Reduction:
Fe₂O₃ → 2 Fe
Oxidation state of Fe in Fe₂O₃ is +3 per atom, and that in Fe is 0. So, Iron has gained 3 electrons per atom and 6 electrons per 2 atoms hence,
Fe₂O₃ + 6e⁻ → 2 Fe
Result:
Iron in Fe₂O₃ has been reduced in this reaction and has played a role of oxidizing agent by oxidizing carbon from +2 state to +4 state.