Which characteristic defines a strong base?

A strong base is defined by its ability to completely dissociate in solution to produce hydroxide ions (OH-). When a strong base, such as sodium hydroxide (NaOH), is dissolved in water, it breaks apart entirely into Na+ and OH- ions. This high concentration of hydroxide ions leads to a significant increase in the pH of the solution, making it very basic (alkaline).

The characteristic of complete dissociation distinguishes strong bases from weak bases, which only partially dissociate in solution, resulting in a lower concentration of hydroxide ions. The ability to produce hydroxide ions is crucial because it is these ions that are responsible for the basic properties of the solution, such as neutralizing acids and contributing to the overall high pH.

The other options refer to characteristics that do not accurately define a strong base. For example, a neutral pH value indicates a balance between hydrogen ions and hydroxide ions, which is not a characteristic of strong bases as they create a basic (higher than 7) environment. Similarly, while hydrogen ions are produced in solutions of acids, strong bases produce hydroxide ions instead, making the focus on hydroxide ions essential for defining them.