Bases produce hydroxide ions (OH–) in aqueous solution. When a base dissolves in water, it increases the concentration of these hydroxide ions in the solution, which is responsible for the basic or alkaline properties of the solution.
When we refer to a base, we often think about substances like sodium hydroxide (NaOH) or potassium hydroxide (KOH). When these bases are added to water, they dissociate into their constituent ions. For example, sodium hydroxide dissociates into sodium ions (Na+) and hydroxide ions (OH–). The presence of the hydroxide ions is what makes the solution basic.
The increase in hydroxide ion concentration is what leads to a rise in pH value. A pH above 7 indicates a basic solution. Therefore, whenever a base is introduced into water, it’s the hydroxide ions that play a crucial role in defining the solution’s characteristics.