Question

How strong are acid and base solutions?

Answer 1

Hint: The acidity or basicity of a solution depends upon its pH value. Higher the value more basic is the solution, lower the pH value more acidic is the solution. If the pH value is seven, then the solution is considered neutral.

Complete answer:
pH denoting potential of \[{\text{hydrogen}}\] is a scale used to specify the acidity or basicity of an aqueous solution. Acidic solutions, which contain higher concentration of \[{H^ + }\] are measured to have lower pH values than basic or alkaline solutions. A strong acid or base completely ionises in the solution.
The pH scale is logarithmic and inversely indicates the concentration of \[{\text{hydrogen}}\] ions in the solution. This is because the formula used to calculate pH approximates the negative of the base \[10\] logarithm of the activity of the molar concentration of \[{\text{hydrogen}}\] ions in the solution. In other words pH is the negative of the base \[10\] logarithm of the activity of the \[{H^ + }\] ion. It is represented by \[ - {\log _{10}}c\] where c is the \[{\text{hydrogen}}\] concentration in moles per litre.
pH scale ranges from zero to fourteen, with seven being neutral. pH of less than seven indicates acidity, whereas pH of greater than seven indicates alkaline or basic.
Acid donates a proton or accepts a pair of valence electrons to form a bond whereas base accepts protons or donate a pair of electrons to form a bond.

Note:
Litmus paper is used to test whether a substance is acid or base, but it doesn’t say anything about the strength of the acidity or basicity, whereas pH shows the comparative strength of the acid and basic solutions.