Multiple Choice
In the Brønsted–Lowry definition, what is an acid?
34
views
17. Acid and Base Equilibrium
Acids Introduction
Multiple Choice
In an aqueous solution, what makes a substance acidic according to the Arrhenius definition?
A
It increases the concentration of ions in water.
B
It increases the concentration of ions in water.
C
It increases the concentration of (or ) ions in water.
D
It decreases the concentration of ions in water.
Verified step by step guidance1
Recall the Arrhenius definition of acids and bases: An Arrhenius acid is a substance that increases the concentration of hydrogen ions (H\(\textsuperscript{+}\)) in aqueous solution, while an Arrhenius base increases the concentration of hydroxide ions (OH\(\textsuperscript{−}\)).
Understand that in water, free hydrogen ions (H\(\textsuperscript{+}\)) do not exist alone; they associate with water molecules to form hydronium ions (H\(\textsubscript{3}\)O\(\textsuperscript{+}\)). Both H\(\textsuperscript{+}\) and H\(\textsubscript{3}\)O\(\textsuperscript{+}\) represent the acidic species in solution.
Identify that an increase in the concentration of H\(\textsuperscript{+}\) or H\(\textsubscript{3}\)O\(\textsuperscript{+}\) ions means the solution becomes more acidic according to Arrhenius theory.
Recognize that increasing concentrations of other ions, such as hydroxide ions (OH\(\textsuperscript{−}\)) or superoxide ions (O\(\textsubscript{2}\)\(\textsuperscript{−}\)), do not define acidity under the Arrhenius definition.
Therefore, the correct statement is that an Arrhenius acid increases the concentration of H\(\textsuperscript{+}\) (or H\(\textsubscript{3}\)O\(\textsuperscript{+}\)) ions in water, making the solution acidic.
Related Videos
Related Practice
