Write a correctly balanced net ionic equation for the reaction that occurs when

Question

Write a correctly balanced net ionic equation for the reaction that occurs when KOI is dissolved in water and calculate the numerical value of the equilibrium constant for the reaction. Calculate the pH of a solution made by combining 60.00 mL of 0.25 M HOI and 31.25 mL of 0.48 M KOH. How many millimoles of solid KOH must be added to 100 mL of 0.25 M HOI to obtain a buffer solution that has a pH of 7.80? Assume that no change in volume occur. When bromine dissolves in water, the reaction is the following: Calculate the pH of such a solution if the concentration of HOBr in the solution is 0.082 M.

Explanation / Answer

I will hel you for now with b) and c).

b) The reaction:
KOI(aq) + H2O(l) ---------> HOI(aq) + KOH(aq)
K+(aq) + OI-(aq) + H2O(l) ---------> H+(aq) + OI-(aq) + K+(aq) + OH-(aq)
Net ionic equation: H2O(l) ---------> H+(aq) + OH-(aq)

The Kw = 1x10-14

c) The Ka for HOI is 3.2x10-11, and in this neutralization reaction, the moles of base are in excess so:

moles OH = 0.48 * 0.03125 = 0.015
Concentration = 0.015 / 0.09125 = 0.0014 M

r: OI- + H2O -------> HOI + OH-
i: 0.0014 0 0
e: 0.0014-x x x

Kb = 1x10-14 / 3.2x10-11 = 3.13x10-4
3.13x10-4 = x2 / 0.0014-x
3.13x10-4 * 0.0014 = x2
x = [OH-] = [HOI] = 6.62x10-4 M
pOH = -log(6.62x10-4) = 3.18
pH = 14-3.18
pH = 10.82

Now for d and e, post them in a different post. Hope this helps

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.