Question

A strong acid is titrated with a weak base. At equivalence point, pH will be
A. ˂7
B. ˃7
C. =0
D. Cannot predict.

Answer 1

Hint: A strong acid is any acid that dissociates completely in solution into ions and gives large numbers of $$H^{+}$$ ions.
A weak base is any base that dissociates incompletely in solution into ions and gives less number of $$O{H}^{-}$$ ions.

Complete step by step answer:
It is given that a strong acid is titrated with a weak base.
Generally the $$pH$$ of an acid is always less than 7.
For strong acids the $$pH$$ will be less than 3-4.
Generally the $$pH$$ of a base is always greater than 7.
For weak bases the $$pH$$ will be 8-9.
In the question it was mentioned that strong acid is going to titrate with weak base, meaning adding weak base to strong acid.
By adding a weak base to strong acid, the $$pH$$ solution of the solution is not going to change in a drastic manner.
Because of the high strength the strong acid can retain it $$pH$$.
Therefore the $$pH$$ of the solution will be less than 7 only.
So, the correct option is A.

Note: Don’t be confused with acid and base. Both are not the same.
An acid is a chemical which releases $$H^{+}$$ ions, when dissolved in water. $$pH$$ of an acid is always less than 7.
A base is a chemical which releases $$O{H}^{-}$$ ions, when dissolved in water. $$pH$$ of a base is always greater than 7.