Label each of the following substances as an acid, base, salt, or none of the above. Indicate whether the substance exists in aqueous solution entirely in molecular form, entirely as ions, or as a mixture of molecules and ions. (d) Ba1OH22.

Key Concepts

Acids and Bases

Acids are substances that donate protons (H+) in a solution, while bases accept protons. The Brønsted-Lowry theory defines acids and bases based on proton transfer, whereas the Lewis theory expands this definition to include electron pair acceptors and donors. Understanding these definitions is crucial for classifying substances correctly.

Ionic and Molecular Compounds

Ionic compounds consist of charged ions held together by electrostatic forces, while molecular compounds are formed by covalent bonds between atoms. In aqueous solutions, ionic compounds dissociate into their constituent ions, whereas molecular compounds typically remain intact. This distinction is essential for determining the form in which a substance exists in solution.

Solubility and Aqueous Solutions

Solubility refers to the ability of a substance to dissolve in a solvent, such as water. When a substance dissolves, it can exist as ions, molecules, or a combination of both, depending on its chemical nature. Recognizing how different substances behave in aqueous solutions helps in identifying their classification as acids, bases, or salts.