Question

A weak base is titrated with a hydrochloric acid solution. What is the pH at the equivalence point?A) equal to pKaB) equal to 7C) equal to pKbD) greater than 7E) less than 7

Answer 1

Answer:

E) less than 7

Explanation:

pH is defined as the negative logarithm of the concentration of hydrogen ions.

Thus,  

pH = - log [H⁺]

pH scale generally runs from 1 to 14 where pH = 7 represents neutral medium, pH < 7 represents acidic medium and pH > 7 represents basic medium.

Strong acids dissociate completely and when they react with base they form a salt of weak base and strong acid.

For example, $BOH$ is a weak base and $HCl$ is the hydrochloric acid.

So,

$BOH+HCl\rightarrow BCl+H_2O$

Thus, the salt is of weak base and strong acid which corresponds to pH less than 7.