$= \frac{{14 + 7 - 3}}{2} - \frac{{21 - 3}}{2} = \frac{{18}}{2} = 9$
${\text{h}} = \sqrt {\frac{{{{\text{K}}_{\text{h}}}}}{{\text{C}}}} = \sqrt {\frac{{{K_w}}}{{{K_a} \times C}}} = \sqrt {\frac{{{{10}^{ - 14}}}}{{{{10}^{ - 7}} \times {{10}^{ - 3}}}}} = \sqrt {{{10}^{ - 14}} \times {{10}^{10}}} = \sqrt {{{10}^{ - 4}}} = {10^{ - 2}}$
$[O{H^ - }] = \sqrt {\frac{{{K_w} \times C}}{{{K_a}}}} = \sqrt {\frac{{{{10}^{ - 14}} \times {{10}^{ - 3}}}}{{{{10}^{ - 7}}}}} = \sqrt {{{10}^{ - 17}} \times {{10}^{ - 7}}} = \sqrt {{{10}^{ - 10}}} = {10^{ - 5}}$
$AgCl\downarrow +2N{{H}_{3}}\rightleftharpoons {{\left[ Ag{{\left( N{{H}_{3}} \right)}_{2}} \right]}^{+}}+C{{l}^{-}}$
નીચેના પૈકી શુ ઉમેરવાથી $AgCl$ ની સફેદ અવક્ષેપ મળશે ?