$CH_3COO^{-}Na^+ + H_2O  \rightleftharpoons  CH_3COOH + Na^{+}OH^{-1}$ 

$1$                      $0$                                  $0$

$\frac{{1 - x}}{v}$            $\frac{x}{v}$              $\frac{x}{v}$

$[O{H^ - }] = C.x = {10^{ - 3}}$

$[{H^ + }] = \frac{{{K_w}}}{{[O{H^ - }]}} = \frac{{{{10}^{ - 14}}}}{{{{10}^{ - 3}}}} = {10^{ - 11}}$

$pH = 11$