In the field of chemical equilibrium, the acidic dissociation constants Ka1 and Ka2 are the key.

Malonic acid dissociates for the first time, and the process can be expressed as: $H_2A\ rightleftharpoons H ^ ++ HA ^ - $. Ka1 in this step indicates the tendency of malonic acid to release protons in the first step. The larger the Ka1 value, the easier the dissociation in the first step, and the stronger the ability of malonic acid to give protons in the first step.

And the second step dissociation, the reaction formula is: $HA ^ -\ rightleftharpoons H ^ ++ A ^ {2 - }$ ， its corresponding Ka2. Generally speaking, because the $HA ^ - $generated after the first step dissociation has been negatively charged, the binding force on the proton is enhanced, so Ka2 < Ka1.

Looking at many chemical reactions, Ka1 and Ka2 of malonic acid affect many balances. Neutralization in acid and base determines the degree of reaction and the product. In the construction of buffer solutions, the system formed by malonic acid and its salts can precisely regulate the pH of the solution by Ka1 and Ka2. From this perspective, it is clear that the research and application of Ka1 and Ka2 in malonic acid in various fields of chemistry are of great significance, which can help us understand the reaction mechanism and control the reaction process.