ABSTRACT
An acid can be defined as a proton donor that increases the concentration of hydrogen ions in a solution. A base can be defined as a proton acceptor, electron pair, or hydroxide ion donor that decreases the concentration of hydrogen ions in a solution. pH is the measurement of the concentration of hydrogen ions (H+) present in a dilute solution. It is the measure of the level of acidity or basicity of a solution. The pH measurement system consists of a pH-measuring electrode, reference electrode and high input meter. The pH-measuring electrode is a glass electrode, which utilizes a thin glass membrane responsive to change in H+ activity. A standard is used to calibrate analytic instruments. Before taking a pH measurement, it is essential to calibrate the pH using standard solutions of known pH. This standardization is necessary to maintain a reference state of pH.
