Q. 99 - An Introduction to General, Organic, and Biological Chemistry

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.

Step-by-Step Solution

Answer

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

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

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

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