Now, acids belong to a distinct class of covalent compounds because of their characteristics in aqueous solutions. Some characteristics of acids include dissolution, taste, reactivity, and how they react with litmus paper.
For dissolution, acids ionize when placed in water. An example is hydrochloric acid, which ionizes in water breaking up into its H+ ion, which is aqueous, plus the chloride ion, which is also aqueous. For sulfuric acid, containing two H+ ions in this compound, it breaks up into 2 H+, aqueous, plus SO42-, aqueous.
For taste, the presence of + ions gives acids a sour taste, as can be observed in natural citrus fruits like lemons and oranges, which have a sour taste because of the natural acids found within them.
Concerning reactivity, acids react with metals to form H2 gas. A good example is hydrochloric acid reacting with magnesium solid. In this reaction, magnesium and chlorine react together to form MgCl2, and the hydrogen becomes H2 gas.
Finally, for litmus paper, a type of paper that changes colors in response to an acid or a base, an acid will change blue litmus paper to red. By taking blue litmus paper and dipping it into an acidic solution, it shows that it's acidic as the litmus paper changes to red. These are some of the common characteristics found with different types of acids.