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Question

Question: Internal indicator is an indicator which is dissolved in the solution where the main reaction is tak...

Internal indicator is an indicator which is dissolved in the solution where the main reaction is taking place.
A. True
B. False

Explanation

Solution

Hint: Internal indicators are those in which one of the reactants behaves as an indicator. Some indicators are also added from outside to check the end point.

Complete step by step answer:__

Indicator is a substance which changes the color during chemical reaction specially during titration. The main purpose of the indicator is to derive the exact end point for the volumetric as well as complexometric titration.
We classify indicators into three categories and these are :self indicator, internal Indicator and external Indicator.

  1. Self indicator: In general these are not an indicator but these are one of the reacting species of titration, which after completion of reaction changes the color of the solution itself.
  2. Internal Indicator: These indicators take part in the reaction and after completion of the titration it changes the color of the solution indicating the sharp end point.
  3. External Indicator: These indicators never take part in the original chemical reaction ,but after completion of reaction these also change the color indicating the endpoint.
    So from the above statement, we can conclude that internal indicators are those which are dissolved in the solution where the main reaction is taking place.
    Therefore, option A is correct.

Additional Information: In general chemical indicators are colorless but when they are dissolved in a reaction they change the color of the solution indicating the end point .External indicators are not recommended to use because it leads to loss of some volume of reaction mixture.
Note: As the indicators are classified into three categories, students sometimes have chances to forget which indicator is what type of work. So, remember that external indicators never take part in chemical reactions(as the name also suggests, it is external).
Self indicators are not any indicator rather than they are just reacting species which behaves as indicator and changes the solution color and indicates the end point, only indicator which takes part in chemical reaction is internal indicator.