In acid reactions, what do the positive hydrogen ions react with?

In acid reactions, positive hydrogen ions (H+) primarily react with other substances, leading to a variety of chemical reactions. Acids are defined by their ability to donate protons, which in this context means they provide hydrogen ions to the solutions they are in. When these hydrogen ions encounter other substances, they can react with bases, metals, carbonates, or other compounds, facilitating different types of chemical reactions.

For instance, when an acid reacts with a base, the hydrogen ions from the acid interact with hydroxide ions (OH-) from the base, neutralizing each other and forming water. Similarly, hydrogen ions can react with metal ions or carbonate ions, producing hydrogen gas or other compounds as products.

While hydroxide ions are indeed substances that hydrogen ions can react with, the term "other substances" encompasses a broader range of possible reactions. Therefore, indicating that hydrogen ions react with other substances captures the essential nature of acid reactions more comprehensively.