Question

A buffer solution is made by dissolving ${\mathrm{H}}_3{\mathrm{PO}}_4\text{and}{\mathrm{NaH}}_2{\mathrm{PO}}_4$in water(10.8)

A. Write an equation that shows how this buffer neutralizes added acid.

B. Write an equation that shows how this buffer neutralizes added base.

Short answer

(A).${\mathrm{H}}_3{\mathrm{PO}}_4$is an acid

(B).${\mathrm{NaH}}_2{\mathrm{PO}}_4$is an base

Step-by-step solution

Step:1 Equation of buffer neutralizes acid

$\text{acid:}{\mathrm{H}}_2{\mathrm{PO}}_4^{-}\left(aq\right)+{\mathrm{H}}_3{\mathrm{O}}^{+}\left(aq\right)\to {\mathrm{H}}_3{\mathrm{PO}}_4\left(aq\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Step:2 Equation of buffer neutralizes base

$\text{base:}{\mathrm{H}}_3{\mathrm{PO}}_4\left(aq\right)+{\mathrm{OH}}^{-}\left(aq\right)\to {\mathrm{H}}_2{\mathrm{PO}}_4^{-}\left(aq\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$