Monthly Archives: November 2020
Posted: November 09, 2020
If you are interested in carrying out reliable pH measurements, then you are probably well-versed in the differences between acids and bases. However, the fundamentals are important to emergent areas of pH metrology and the importance of pH buffer solutions so we will recap the basics briefly.
Accurate pH Measurements with Buffer Solutions
Formally, the pH value of a substance denotes the negative logarithm of hydrogen ion activity. This is sometimes referred to as the potential, or power, of hydrogen in an aqueous solution. The pH of a solution is expressed on a scale of 0–14 and it is a temperature-dependent property. Pure water, for instance, is largely neutral with a pH of 7.47 at 0°C and 6.14 at 100°C.
Measuring the pH value of a solution is typically done using a potentiometer which – theoretically – produces a 0 millivolt (mV) differential between a sensing and reference electrode at pH 7. Any change in acidity or alkalinity changes the ele