Chapter 8, Problem 193MP

Consider a solution prepared by mixing the following:

$\text{50}\text{.0 mL of 0}{\text{.100 M Na}}_{\text{3}}{\text{PO}}_{\text{4}}$

$\text{100}\text{.0 mL of 0}\text{.0500 M KOH}$

$\text{200}\text{.0 mL of 0}\text{.0750 M HCl}$

$\text{50}\text{.0 mL of 0}\text{.150 M NaCN}$

Determine the volume of $\text{0}{\text{.100 M HNO}}_{\text{3}}$ that must be added to this mixture to achieve a final $\text{pH}$ value of $\text{7}\text{.21}$ .