If you titrate nitric acid with sodium hydroxide, you will add a drop or two of phenolphthalein to the sample of acid before you begin adding the sodium hydroxide. Why is the indicator added?

1 Answer
Nov 16, 2015

Answer:

The Acid-Base indicator from its name it means that it will indicate that the equivalence point (or end point) of the titration is reached.

Explanation:

The Acid-Base indicator from its name it means that it will indicate that the equivalence point (or end point) of the titration is reached.

At the equivalence point, #n_(H^+)=n_(OH^-)#.

The phenolphthalein is an acid-base indicator that is colourless in acidic medium and #color(pink)("pink")# in basic solution.

Watch this video that explains in details the acid - base titration.
Lab Demonstration | Acid - Base Titration.