Question

which term describes a substance that increases the concentration of hydroxide ions in solution?
○ lewis definition of an acid
○ arrhenius definition of a base
○ bronsted-lowry definition of a base
○ bronsted-lowry definition of an acid

Explanation:

• The Lewis definition of an acid is an electron - pair acceptor, so it's not related to increasing hydroxide ions.
• The Arrhenius definition of a base states that a base is a substance that dissociates in water to produce hydroxide ions ($\ce{OH^-}$), thus increasing the concentration of hydroxide ions in solution.
• The Bronsted - Lowry definition of a base is a proton ($\ce{H^+}$) acceptor, and it doesn't specifically focus on producing hydroxide ions.
• The Bronsted - Lowry definition of an acid is a proton donor, which is the opposite of what we need here.

Answer:

B. Arrhenius definition of a base