45.2: Introduction
( \newcommand{\kernel}{\mathrm{null}\,}\)
Acids contribute hydrogen ions (H+) into a solution during a chemical reaction, making them proton donors. Bases contribute hydroxide ions (OH−) into a solution during a chemical reaction or bond with a proton making them proton accepters. Phenol solution turns yellow in acidic solutions and remains red in basic solutions. There are many indicators that a chemical reaction has occurred, including color change.