A liquid has a pH less than 7 which represent an acidic solution:
(i) State the nature of solution, if its pH increases from 7 to 14.
(ii) Mention the ion whose concentration increases with the increase in pH value.
(iii) Suggest a method that is generally used for measuring the pH value.

Explanation

(i) There is increase in the strength of alkali, so the nature of solution will be basic.
(ii) Hydroxide ion or Hydroxyl ion or `OH^-` ion
(iii) A paper impregnated with the universal indicator is generally used to measure the pH of a solution.