Chapter 15, Problem 15.10A

Interpretation Introduction

Interpretation:

Determine the concentrations of hydroxide and hydronium ions given the K_wof the water at 50 °C. The concentrations can be determined using the equilibrium expression for water.

Concept introduction:

• The equilibrium constant of an acid is referred to as the K_aand uses the formula:
  K_a= $\left[H^{+}\right]\left[A^{-}\right]/\left[HA\right]$
• The equilibrium constant expression for water gives us the value of K_wwhich has the following formula: $K_w=\left[O{H}^{-}\right]\left[H_3{O}^{+}\right]$
• We can use the equilibrium expression to determine the concentration of H₃O+ ions which we use to calculate the pH of a solution using: $pH=-log\left[H_3{O}^{+}\right]$
• We can also use the OH- concentration to find $pOH=-log\left[O{H}^{-}\right]$
• The relationship of pOH and pH is: $pH+pOH=14$

To classify:

The concentration of OH- and H₃O⁺.