Chapter 22, Problem 19R

To determine

To compare: The given pair of acid and salt.

Explanation of Solution

Introduction:

The reaction of acid and base results in the formation of a salt and water. This is known as neutralization reaction. The general reaction is represented as follows:

  $\text{HA}+\text{BOH}\to \text{AB}+{\text{H}}_{\text{2}}\text{O}$

Here, HA is acid, BOH is base, AB is salt and ${\text{H}}_{\text{2}}\text{O}$ is water.

The above reaction is a neutralization reaction because resultant solution is neutral in nature.

The comparison is done as follows:

Acid	Salt
The species which gives hydrogen ion/s in the aqueous solution.	The species which dissociates into the respective ions in the aqueous solution. In a neutral salt, the concentration of hydrogen and hydroxide ions remains the same.
They are sour in taste.	They are not sour but salty in taste.
Acids turn blue litmus paper red and there is no change in the red litmus paper.	Salt being neutral in nature does not change color of red and blue litmus paper.
The pH value for an acidic solution is less than 7.	The pH value for a salt solution is 7 because it is neutral in nature.
Examples of acids known from everyday life are acetic acid (vinegar), HCl (also known as stomach acid) etc.	Example of salt used in everyday life is sodium chloride (NaCl).

Conclusion:

Thus, acids have pH value less than 7 and they have a greater number of hydrogen ions than a salt solution. A salt is formed after reaction of an acid and a base. Thus, a salt solution can be acidic or basic depending on the type of acids and bases reacting in the reaction. The salt formed after the reaction of a strong acid and weak base is acidic in nature and the salt formed from weak acid and strong base is basic in nature, they are termed as acidic and basic salts, respectively.