On the PH value of strong acid and strong alkali neutralization

In item C, the acetic acid solution with pH=4 is mixed with the sodium hydroxide solution with pH= 10. Because acetic acid is a weak acid, its ionization degree is small, and pH=4 means that its ionized hydrogen ion concentration is/kloc-0 /×10-4 mol L-1.A large amount of acetic acid exists in molecular form (implying a large amount). When mixed with sodium hydroxide solution with pH= 10, the original ionized part can be. In fact, in the process of reaction, acetic acid will continue to ionize hydrogen ions due to the consumption of the original ionized hydrogen ions, making the final solution acidic.

Similarly, in item D, the concentration of hydroxyl ions after ionization by ammonia water with pH= 10 is1×10-4 mol L-1,and a large amount of ammonia monohydrate exists in molecular form (implying a large number of hydroxyl ions). During the reaction, acetic acid will continuously ionize hydroxyl ions, making the final solution alkaline.

Your so-called "strong acid is acidic when it meets weak base." Strong base is alkaline when it meets weak acid. "Generally speaking, it essentially refers to the reaction of strong acid and weak base to generate strong acid and weak base salt, which is acidic after hydrolysis.

When solving a problem, we should consider not only its origin, but also its quantity. Treat them differently. You can reconsider the problem and think it over. Drop a drop of very dilute nitric acid into very concentrated ammonia water. What is the essence of the solution?