Chapter 22, Problem 15STP

To determine

To compare: The terms strength and concentration which are applied to acids and bases in the solution.

Explanation of Solution

Introduction:

Acids and bases are substances which give ions in the aqueous solution. Acid gives hydrogen ions in the solution, whereas base gives hydroxide ions in the solution.

The strength of any solution is defined as the measure of degree of ionization. It will depend on the number of dissociated ions. If the number of cations and anions produced in the solution is more, the strength of the solution will be more. For example, HCl and NaOH are strong acid and strong base respectively so, number of dissociated ions will be high in their solutions. Similarly, acetic acid and ammonia are weak acid and base, respectively. They do not completely dissociate into their respective ions. The number of dissociated ions will be less in case of weak acid or base.

The concentration of any solution is the measure of amount of ions of acid dissolved in a solvent. This can be measured in terms of moles, percentage, and ppm. The concentration is ratio of content of solute to the content of solvent of the solution. If in a solution, number of acidic ions or basic ions are less with respect to the solvent (generally water), it will be considered as a dilute solution and if ions are more, it will be a concentrated solution.

Conclusion:

Thus, strength of an acid and base define strong and weak acid or base, but concentration define concentrated and dilute acid or base.