Question

How is $pH$ related to solution acidity?

Answer 1

‌$pH$ is a negative logarithm of concentration of hydrogen ion. It is used to determine and calculate the strength of acid and base. Acid is a substance that has the ability to donate protons. Examples of acid are hydrochloric acid, sulphuric acid, nitric acid.

Complete step by step answer:
A scale is used to determine the nature of the substance. This is known as $pH$ scale. It ranges from $0$ to $14$ . The increase and decrease in the value tell us about the acidity and basicity of a solution
$pH$ paper is also used to determine the nature of substance. The substance changes its color and indicates nature. If a paper changes its color from red to blue, then the solution is basic and if a paper changes its color from blue to red, then the solution is acidic.
If the $pH$ of a solution in $pH$ scale lies below $7$ , then the solution is said to be acidic and if the $pH$ of a solution in $pH$ scale lies above $7$ then the solution is said to be basic. If $pH$ lies exactly at $7$ then it is considered as neutral.
If the concentration of hydrogen ions is high, then the $pH$ is very low because the overall concentration of hydrogen ions is inversely proportional to $pH$ . this is because the $pH$ of the solution is equal to the negative logarithm of the concentration of hydrogen ions. Acids are the substances that provide hydrogen ions.

Note: The $pH$ of the solution depends on the temperature. If we change the temperature, the $pH$ also changes.The $pH$ paper is not accurate. For example, if the $pH$ is less than zero, that means it will not show accurate value.