Question

Statement: The selected indicator for acid-base titration is one which has $p{K}_{ln}=pH$ (at point) $\pm 1$.

If the given statement is true enter 1, else enter 0.

Answer 1

An acid & base indicator is a substance which changes its colour within limits with variation in pH of the solution to which it is added. Indicators, in general, are either organic weak acids or weak bases with the characteristics of having different colours in the ionized and unionized form

e.g. phenolphthalein is a weak acid (ionized form is the pink and unionized form is colourless).

In general pH range of indicator lies between $p{K}_{ln}=pH$ (at point) $\pm 1$

Hence, the given statement is $true$ and the correct entry is $1$