Selection of indicators in acid-base titration and PH curve
Selection of indicators in acid-base titration
The amount of an acid (or a base), which is exactly equivalent chemically to the amount of some standard base (or an acid), is determined by an acid-base titration. The point of equivalence is called end point. The solution of a strong acid and strong base will be neutral at the end point and have a pH of 7 as they are strong electrolytes. However, if either the acid or the base is a weak electrolyte, the solution at the equivalence point will be either slightly alkaline (pH>7) or slightly acidic (pH<7).>+ ion concentration (i.e. pH), which depends upon the nature of the acid and the base and the concentration in the solution.
A large number of acid-base indicators are available which possess different colours according to H+ion concentration of the solution. These indicators do not change from predominantly 'acid' colour to predominantly 'base' suddenly and abruptly, but within a small interval of pH (generally about 2 pH units). This is called colour-change interval of the indicator. The position of the colour-change interval in the pH scale varies widely with different indicators. Therefore, for acid base titrations, an indicator is chosen which shows a distinct colour change at a pH close to that of equivalent point.
please double check your indicator colors
ReplyDeletePlease check your indicator colors
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