What does a base produce according to the Arrhenius definition?

According to the Arrhenius definition, a base is a substance that, when dissolved in water, produces hydroxide ions (OH-). This definition highlights the relationship between bases and the generation of hydroxide ions in an aqueous solution.

When a base, such as sodium hydroxide (NaOH), is dissolved in water, it dissociates to release hydroxide ions, which contributes to the solution's basic properties. The presence of these OH- ions increases the pH of the solution, making it alkaline.

This understanding of bases as hydroxide ion producers is fundamental to various chemical processes, including neutralization reactions, where an acid and a base react to form water and salt. Other options, such as hydrogen ions or oxygen molecules, do not align with the Arrhenius definition of bases, as they specifically relate to acids and other chemical reactions. Additionally, the formation of salt and water occurs in neutralization reactions, which involve both acids and bases, rather than being a defining feature of bases alone.