Question

Dissolving $NaCN$ in de-ionized water will result in a solution having

• A. pH < 7
• B. pH = 7
• C. pOH = 7
• D. pH > 7

Answer 1

Answer: (D)

pH > 7

Answer 2

$\because$ On dissolving NaCN in de-ionised water, following reaction takes place.
$CN ^{-}+ H _{2} O \rightleftharpoons HCN + OH ^{-}$
$\because CN ^{-}$ions come from the salt of strong base and weak acid.
$\therefore$ The solution becomes basic and $pH >7$.