Chemistry: The Central Science (13th Edition)

The most appropriate drawing of that curve is in second drawing. $- (ii)$
- The original solution is made of a strong base. Therefore, its pH should be high (greater than 7). - Since we are adding a strong acid: The hydronium ion concentration should raise, decreasing the pH. The only drawing where the pH is decreasing with the addition of the compound is the number $(ii)$