Question

he number of hydrogen ions would equal the number of hydroxide ions in a solution with a pH of _____.

Answer 1

The number of hydrogen ions would equal the number of hydroxide ions in a solution with a pH of 7.

Explanation :

The substance’s acidic or basic nature is determined by its pH value which is the indication of the number of free hydrogen ion ($H^{+}$). The pH value and the alkalinity can be measured by pH scale which varies from 0 to 14. Neutral water has the pH value of 7 with equal number of hydrogen ions ($H^{+}$) and Hydroxide ions ($O H^{-}$).

A substance with a pH value above than 7 is counted amongst the base whereas those with a pH value are counted amongst the acids. When a solution gets ten times more acidic, the pH value falls by the count of one.  

There are various methods to determine the pH value of any substance and the most effective and quick one is the pH indicator paper. When the indicator paper is dipped in the water solution of the substance, it colour changes according to the different pH value. Another effective method to determine the pH value is the use of pH electrodes.