"On the Strength and Weakness of Phosphoric Acids"

The world has its own way of discussing the strength and weakness of acids. Or observe its degree of ionization, or observe the intensity of its reaction with other substances. Phosphoric acid, its strength is also discussed by everyone.

Phosphoric acid can be ionized in water. However, its ionization constant is quite different from that of strong acids. Strong acids are almost completely ionized in water, while phosphoric acid ionization constant is limited, only partial ionization. From this perspective, phosphoric acid is different from strong acids, and it is difficult to call strong acids.

Furthermore, observe its reaction with bases. In case of alkali neutralization, its performance is not as rapid as strong acids. When a strong acid meets a base, it responds in an instant, and the heat output is very dramatic. Compared with phosphoric acid, the reaction is slow, and the heat output is also small. This is another proof that it is not a strong acid.

Or some people say that phosphoric acid is also active in some situations. However, this activity is not on the same level as strong acids. Its activity is mostly due to changes in the reaction system, or the catalysis of other things, and it is strong unless it is its nature.

To sum up, phosphoric acid is not a strong acid. Although it has its use in the field of chemistry, the strength of nature should be determined by reality and cannot be judged arbitrarily.