Chemistry questions!! I need help? 3. Consider the HCIO/CIO conjugate acid/base

Question

Chemistry questions!! I need help?

3. Consider the HCIO/CIO conjugate acid/base pair. Consult your text or other source for appropriate acid dissociation constants. The hypochlorite ion is the active ingredient in bleach, NaCIO(aq). (a) Explain why this acid/base pair would be a candidate for a buffer with pH 7.3 (approximate physiological value). (b) Based on your advice in 3(a), a researcher used this very buffer in a growth medium (including appropriate food and temperature control) for bacteria that proliferate at physiological pH. Despite this carefully prepared medium, however, bacterial growth was dismal. Explain

Explanation / Answer

(a) Ka of this conjugate acid/base pair is 3* 10^-8

pKa =-logKa = 7.52

The equilibrium HOCl <==> OCl- + H+ occurs around pH 7.52. So, this pair will be able to act as a buffer at pH = 7.3

(b) A buffer can resist the change in pH if small amount of H+ or OH- is added to the system, However, if there is a large amount of H+ or OH- is added, pH will not be maintained. This could be the main reason behind poor bacterial growth.

---------------------------

4. (a) H2PO4^-/HPO4^2- pair which has a pKa value 7.21

conjugate acid of this pair = H2PO4^-

(b) pH = 7.25 means there is equal amount of H2PO4^2- and HPO4- present

[conjugate acid] = 0.2/2 = 0.1 M

[base] = 0.1

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---

---

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