Question

What is the \[pH\] value of \[KCl\]?

Answer 1

Hint: \[pH\] describes the concentration of hydrogen ion \[\left( {{H^ + }} \right)\] in the solution. \[pH\] can have values ranging between 0 and 14. On the basis of \[pH\]value, the compounds are categorised as acids, bases and neutral. For a neutral solution, the value of \[pH\]is equal to 7.

Complete answer:
We know \[KCl\] alkali metal halide has a salt-like taste. On dissolution in water, it will give potassium\[{\kern 1pt} ({K^ + }){\kern 1pt} \] and chloride ion\[{\kern 1pt} {\kern 1pt} (C{l^ - })\] into the solution. This is illustrated in the following diagram:
\[KCl{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} \to {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {K^ + }{\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} + {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} {\kern 1pt} C{l^ - }\]
From the above diagram, we can say that \[KCl\] neither increases nor decreases the concentration of hydrogen ions \[\left( {{H^ + }} \right)\] in the solution. Therefore, the resulting solution is neutral. For neutral compounds, the value of \[pH\]is equal to 7.
Therefore, the \[pH\] value of \[KCl\] solution is 7.

Additional Information:
The solution having low \[pH\] value (0-7) is acidic in nature while the solution having high \[pH\] value (7-14) is basic in nature. \[pH\] paper and \[pH\] meter are usually used to determine the nature of the solution. \[pH\] paper is available in the form of strips and used to determine whether the solution is acidic (blue litmus red), basic (red litmus blue), and neutral (change doesn’t occur). On the other hand, \[pH\] meter describes the exact value of the \[pH\]. \[KCl\]is an ionic compound because potassium can easily donate one electron and chloride can easily accept one electron.

Note:
It is important to note that dissolution of \[KCl\] in water doesn’t change the concentration of hydrogen ion \[\left( {{H^ + }} \right)\]. It means that \[KCl\] is a neutral compound (salt). For neutral compounds, \[pH\] of the solution is equal to 7.