A) The following graph shows the pH curve for the titration of 25 mL of a 0.1 M

Question

A) The following graph shows the pH curve for the titration of 25 mL of a 0.1 M monoprotic acid solution with a 0.1 M solution of a monoprotic base.

(1) The pH curve represents the titration of a _______weakstrong acid with a _______weakstrong base.

(2) Choose a suitable indicator for the endpoint of the titration from the following pulldown list.
_________Bromocresol greenMethyl redBromothymol blueCresol redThymol bluePhenolphthalein

B) The following graph shows the pH curve for the titration of 25 mL of a 0.1 M monoprotic acid solution with a 0.1 M solution of a monoprotic base.

Please explain and make sure its correct :) Thank you

Explanation / Answer

FIRST PART

(1) The pH curve represents the titration of a _______weakstrong acid with a _______weakstrong base.

Note that there is a buffer formation area between V = 0 and V = equivalence, so this must be a WEAK acid.

Also, note that pH won't go up to 10-12 area, which is typical for strong acid, so this must have been titrated with a WEAK base

(2) Choose a suitable indicator for the endpoint of the titration from the following pulldown list.

The best indicator must change near the pH of euqivalence, so pH = 7

from the list:

Bromomethyl blue or even cresol red could helpt

SECOND PART

(1) The pH curve represents the titration of a _______weakstrong acid with a _______weakstrong base.

clearly, this is a strong acid, since pH is low, no buffer formation, so strong acid initially

then it is titrated with a base, the base must be strong, since the hange in pH is drastical, so strong base

(2) Choose a suitable indicator for the endpoint of the titration from the following pulldown list.

No that the pH is about 7 in equivalence point

so

choose

Bromomethyl blue or even cresol red, or even phenolphtalein will do

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.