Q1: What is a pH electrode?
A1: The pH electrode is also called the pH probe pH sensor. The pH electrode is the part of the pH meter that is in contact with the substance to be measured and is used to measure the electrode potential.
Q2: Why do pH electrodes need to be soaked?
A2: The pH electrode must be soaked before use, because the pH bulb is a special glass membrane with a thin hydrated gel layer on the surface of the glass
membrane, which can only interact with the H+ ions in the solution under fully wet conditions. the response to. At the same time, after soaking the glass
electrode, the asymmetric potential can be greatly reduced and tend to be stable.
Q3: What is a reference electrode?
A3: An electrode with a known and constant electrode potential that does not respond to the activity of hydrogen ions in solution is called the reference electrode. Reference electrodes include mercurous sulfate electrodes, calomel electrodes, and silver/silver chloride electrodes. The most commonly used are calomel electrodes and silver/silver chloride electrodes. The role of the reference electrode in the measurement cell is to provide and maintain a fixed reference potential, so the requirements for the reference electrode are that the potential is stable and reproducible, the temperature coefficient is small, and the polarization potential is small when current flows.
Tips: What is a two-junction reference electrode?
The double junction reference electrode consists of two junction boundaries and two reference solution chambers. The outer chamber is generally filled with potassium nitrate solution, while the inner chamber is filled with potassium chloride solution. It has two distinct advantages. One is to reduce pollution. The tested solution can only contaminate the solution in the outer chamber and has limited influence on the kcl solution in the inner chamber. Second, it reduces the clogging of the liquid junction and chemical reactions between ions.