Question

what does equivalence point refer to during a titration? the chemical for which the volume is known, but the concentration is not. the point during a titration where the indicator changes color. the point where moles of acid equals moles of base. the chemical for which both the concentration and volume are known.

Explanation:

In a titration, the equivalence point is defined by the stoichiometric balance of reactants. For acid - base titrations, this means the moles of acid equal the moles of base (based on the reaction's stoichiometry).

• The first option describes a solution of unknown concentration (not the equivalence point).
• The second option is the definition of the end - point (where the indicator changes color, which may be close to but not exactly the equivalence point).
• The fourth option describes a standard solution (not the equivalence point).

Answer:

The point where moles of acid equals moles of base.