Question

Calculate the pH of a solution formed by mixing 550.0 mL of 0.30 M HClO with 275.0 mL of 0.20 M CsClO. The Ka for HClO is 2.9 × 10-8.

Answer 1

pH = 7.08

Step-by-step explanation:

We can solve this problem using Henderson-Hasselbach's equation:

• pH = pKa + log
  `([ClO^-])/([HClO])`

With the given concentrations and volumes, we can calculate the new values for [ClO⁻] and [HClO] when the solutions are mixed:

• Total volume = 550.0 mL + 275.0 mL = 825.0 mL

• [HClO] = 550 mL * 0.30 M / 825 mL = 0.20 M

• [ClO⁻] = 275 mL * 0.20 M / 825 mL = 0.07 M

Now we calculate pKa:

• pKa = -log(Ka) = 7.54

Finally we calculate the pH:

• pH = 7.54 + log
  `(0.07)/(0.2)` = 7.08