Question

How would you determine the pH of$ 0.125 \ M$ solution of nitric acid?

Answer 1

Hint: pH denotes the power of hydrogen or we can say that it represents potential of hydrogen ions. It is generally a scale which is used to represent that aqueous solution given is acidic in nature, basic in nature or in neutral form.

Complete answer:
pH scale is said to be logarithmic because it inversely indicates the concentration of hydrogen ions in the solution. Formula used to calculate pH approximately equal to the negative of the base 10 logarithmic of the molar concentration which can be represented as follows:
$pH=-{{\log }_{10}}[{{H}^{+}}]$
Nitric acid is a highly corrosive mineral acid which is colorless if pure but sometimes acquires yellow color due to decomposition into oxides of nitrogen and water. Nitric acid is represented by the chemical formula of$HN{{O}_{3}}$. It is a strong acid due to it. We can assume that it dissociates properly in an aqueous solution so this is known to be mono tropic. Term mono tropic refers to those compounds which provide one mole of hydrogen ions per mole of acid so we can say that the concentration of hydrogen ions in solution is equal to the concentration of the acid which is given as 0.125 M.
Now pH can be easily find out by using its equation:
$pH=-{{\log }_{10}}[{{H}^{+}}]$ i.e. $pH=-{{\log }_{10}}[0.125]$
$= 0.903$
Hence, the pH of 0.125 M solution of nitric acid is 0.903.

Note: pH scale ranges from 0-14 where the solution which has the value greater than 7 is basic in nature and those solutions who have value less than 7 are acidic in nature and those who have exact 7 value are said to be neutral in nature.