Question

How can an indicator be used to show when all the sodium hydroxide has reacted with sulfuric acid?

A) The indicator will change color when all the sodium hydroxide has reacted.
B) The indicator will emit a sound signal when all the sodium hydroxide has reacted.
C) The indicator will produce a distinct odor when all the sodium hydroxide has reacted.
D) The indicator will become lighter in weight when all the sodium hydroxide has reacted.

Answer 1

The correct answer is A) The indicator will change color when all the sodium hydroxide has reacted, as seen in acid-base titrations using phenolphthalein, which turns pink at the equivalence point.

Step-by-step explanation:

An indicator can be used to show when the reaction between sodium hydroxide and sulfuric acid is complete by exhibiting a change in color. This is typically observed during an acid-base titration, where the equivalence point is indicated by the color change of an indicator. A commonly used indicator for a titration involving a strong acid and a strong base is phenolphthalein, which changes from colorless to pink as the solution shifts from acidic to basic. Therefore, the correct answer is A) The indicator will change color when all the sodium hydroxide has reacted.