The pH of a neutral solution is _____.
Answer & explanation
Correct answer: option 1
The correct answer is option (1) 7.
The pH scale is a measure of the acidity or basicity (alkalinity) of a solution. It ranges from 0 to 14, where:
pH values less than 7 indicate acidity.
pH values equal to 7 indicate neutrality.
pH values greater than 7 indicate alkalinity (basicity).
The pH of a neutral solution, such as pure water, is exactly 7. In a neutral solution, the concentration of hydrogen ions (\(H^+\)) is equal to the concentration of hydroxide ions (\(OH^-\)), resulting in a balanced condition. The equation for the ionization of water, which illustrates the balance between \(H^+\) and \(OH^-\), is:
\[ H_2O \rightleftharpoons H^+ + OH^- \]
For a neutral solution:
\[ [H^+] = [OH^-] \]
In mathematical terms, this equilibrium corresponds to a pH value of 7. The midpoint of the pH scale (7) represents the neutral point.
Therefore, when you encounter a question stating that a solution is neutral, you can confidently identify it as having a pH of 7.