Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
According to Arrhenius definition, an acid is any substance that increases the concentration of hydrogen ions (H+) when dissolved in water, and a base is any substance that increases the concentration of hydroxide ions (OH-) when dissolved in water.
Related terms
Arrhenius Acid: A substance that increases the concentration of hydrogen ions when dissolved in water.
Arrhenius Base: A substance that increases the concentration of hydroxide ions when dissolved in water.
Ionization: The process by which an atom or molecule acquires a negative or positive charge by gaining or losing electrons to form ions.