Question

The steepest point on the curve where the equivalents of acid present equal the equivalents of base added (or vice-versa) is called the

a. Equivalence point
b. Buffer region
c. Inflection point
d. End point

Answer 1

The equivalence point is the stage in a titration where the amounts of acid and base are equal, and it is represented on a titration curve by the inflection point. The pH at this point can vary depending on the nature of the titrants involved: pH 7 for strong acid-strong base titration, above 7 for weak acid-strong base, and below 7 for strong acid-weak base titrations.

Step-by-step explanation:

The equivalence point in a titration is the moment when the moles of acid and base in the solution are stoichiometrically equal. It's often represented on a titration curve as the steepest point or inflection point, where the pH changes most rapidly. In a strong acid-strong base titration, the pH at the equivalence point is 7. However, in a weak acid-strong base titration, the pH will be greater than 7 at the equivalence point, while in a strong acid-weak base titration, it will be less than 7.

The point where the indicator changes color is referred to as the end-point, which ideally should coincide with the equivalence point. It is important to recognize that in titration of a weak acid or a weak base, the midpoint - where half of the acid or base has been neutralized - forms a buffer region, but it is not the equivalence point.