Which indicator of those you used would you expect to be useful in determining t

Question

Which indicator of those you used would you expect to be useful in determining the pH of a 4.0 times 10^-4 M HCl solution? Why? From your pH measurements, calculate a K_a for each acetic acid solution using equation (4) and the method outlined in the introduction. Show your work. How well do your values compare with the accepted value of K_a for acetic acid? For each salt. solution whose pH is no. within 1 unit. of 7, write the net ionic equation for the reaction responsible for the acidity or basicity of the solution.

Explanation / Answer

2. the best indicator for the pH of 4 x 10^-4 M HCl would be bromocresol purple which is yellow at the pH of HCl = 3.4.

3. Ka for acetic acid = [H3O+][A-]/[HA]

knowing pH,

pH = -log[H3O+]

[H3O+] = [A-]

and, [HA] concentration we can determine Ka for each solution

4. for basic salts as,

Na2CO3, net ionic equation would be,

CO3^2- + H2O <==> HCO3- + OH-

NaHCO3, net ionic equation would be,

HCO3- + H2O <==> H2CO3 + OH-

similarly other salts which gives OH- ion in solution are basic and the ones that gives H3O+ in solution are acidic in nature,

acidic salts like, NH4+

NH4+ + H2O <=> NH3 + H3O+

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

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