Question

a titration curve of an unknown acid whose equivalence point is at pH 7 segguest that?

a) this is a weak acid because the equivalence point of all strong acids is below 7

b) this is a strong acid because the  equivalence point of all strong acids is pH 7

c) this is a weak acid because the  equivalence point of all weak acids is pH 7

d) this is actually pure water

please explain as much as you can. i think it is D, but im not sure

Answer 1

In a titration, the equivalence point indicates whether the acid or base is strong or weak.

If the equivalence point is exactly pH7 then the acid or base is strong.

If the equivalence point is greater or smaller than pH7 then the acid or base is weak.

Explanation: remember the conjugate rule:

The conjugates of strong acids or bases are neutral, that is pH 7 because strong acid or bases will dissociate completely. But the conjugates of weak acid or bases are slightly acidic or basic, that is slightly greater or smaller than pH7 because weak acid or bases does not dissociate completely.

Therefore, correct answer for this question is (B)