Chapter 16, Problem 24A

Interpretation Introduction

Interpretation:

The P^H of the given pair of solutions have to be calculated. The pair of solution having more acidic nature have to be indicated.

Concept Introduction:

The acidity or alkalinity of a solution is expressed by determining P^H of the solution. P^H of a solution is defined as negative logarithm of the concentration of H+ ion in the solution. P^H is expressed as-

  ${\mathrm{P}}^H=-log[H^{+}]$

Answer to Problem 24A

1. Here, P^H of this pair of solution are 2.92 and 3.35.So this pair of solution represents more acidic solution.

Explanation of Solution

To determine which pair of solution is more acidic, pH of each solution needs to be determined.

1. Data given: [H⁺] = 1.2 × 10-3 M or [H⁺] = 4.5 × 10-4 M

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[1.2\times 10^{-3}]\\ =2.92\end{array}$

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[4.5\times 10^{-4}]\\ =3.35\end{array}$

Here, P^H of this pair of solution are 2.92 and 3.35.So this pair of solution is more acidic.

2. Data given: [H⁺] = 2.6 × 10-6 M or [H⁺] = 4.3 × 10-8 M

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[2.6\times 10^{-6}]\\ =5.58\end{array}$

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[4.3\times 10^{-8}]\\ =7.37\end{array}$

Here, P^H of this pair of solution are 5.58 and 7.37.So in this pair of solution one is acidic and other is basic.

3. Data given: [H⁺] = 0.000010 M or [H⁺] = 0.0000010 M

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[0.000010]\\ =5.0\end{array}$

  $\begin{array}{l}{P}^H=-log[H^{+}]\\ =-log[0.0000010]\\ =6\end{array}$

Here, P^H of this pair of solution are 5.0 and 6.0.So this pair of solution is acidic.