Question

In which of the following acid / base titrations, can
we NOT determine the
equivalence point in an accurate
manner?
strong acid / strong
base
strong acid / weak
base
weak acid / strong
base​

Answer 1

Answer:

At the equivalence point, all of the weak acid is neutralized and converted to its conjugate base (the number of moles of H+ = added number of moles of OH–). However, the pH at the equivalence point does not equal 7. This is due to the production of conjugate base during the titration.

Answer 2

The Weak Acid-Strong Base Titrations acid/base titrations, we cannot determine the equivalence point in an accurate manner.

• The pH variation throughout titration is represented by a titration curve, which indicates the strength of the associated acid and base.
• The pH variation even during titration of a strong base with such a weak acid can be seen on the titration curve, which indicates that the pH changes slowly and progressively at first.
• As the titration reaches the equivalence point, this suggests the establishment of a buffer system.
• Such a curve is characteristic of the titration of NaOH and HCl just at the equivalence point and even beyond. When NaOH levels are too high, the pH changes in the same way it does in almost any collective action by NaOH.
• At the initiation of the titration, the ph level is similar to that of a weak acid in a liquid. All weak acid is neutralized and transformed to their corresponding base just at the equivalence point (molar mass of H+ = additional molar mass of OH–).
• The pH at the equivalency point, however, does not equal 7. This is owing to the titration generation of the conjugate base. The result is a fairly basic solution.
• The equivalence point, as well as, the endpoint are not the same thing: the equivalence point is shown by the reaction's stoichiometry, but the endpoint is simply the colour change from the indicator.