Chapter 6, Problem 6A.3BST

(a)

Interpretation Introduction

Interpretation:

The concentration of ${\text{H}}_{\text{3}}{\text{O}}^{+}$ has to be estimated.

Concept Introduction:

To find the hydronium ions concentration use autoprotolysis constant.  Autoprotolysis is a reaction in which proton is transfer from one molecule to another molecule of same kind.  Autoprotolysis constant can be expressed by the equation shown below;

    $K_W=[{\text{H}}_{\text{3}}{\text{O}}^{+}][{\text{OH}}^{-}]$

For pure water the value of autoprotolysis constant is equal to $1.0\times {10}^{-14}$ at $\text{25°C}$.  Unit of autoprotolysis constant is ${\text{mol}}^{\text{2}}\cdot {\text{L}}^{-2}$.  This is because, the unit for concentration of hydroxide ion and hydronium ion is $\text{mol}\cdot {\text{L}}^{-1}$.

(b)

Interpretation Introduction

Interpretation:

The concentration of ${\text{OH}}^{-}$ has to be estimated.

Concept Introduction:

Refer to part (a).