Search results
Results From The WOW.Com Content Network
A glass electrode is a type of ion-selective electrode made of a doped glass membrane that is sensitive to a specific ion. The most common application of ion-selective glass electrodes is for the measurement of pH. The pH electrode is an example of a glass electrode that is sensitive to hydrogen ions.
To measure the pH of a solution, the electrodes are used as probes, which are dipped into the test solutions and held there sufficiently long for the hydrogen ions in the test solution to equilibrate with the ions on the surface of the bulb on the glass electrode. This equilibration provides a stable pH measurement.
A platinum wire electrode is immersed in a saturated aqueous solution of quinhydrone, in which there is the following equilibrium C 6 H 6 O 2 ⇌ C 6 H 4 O 2 + 2H + +2e −. The potential difference between the platinum electrode and a reference electrode is dependent on the activity, +, of hydrogen ions in the solution.
Potentiometry passively measures the potential of a solution between two electrodes, affecting the solution very little in the process. One electrode is called the reference electrode and has a constant potential, while the other one is an indicator electrode whose potential changes with the sample's composition. Therefore, the difference in ...
The electrode potential is proportional to pH when pH is defined in terms of activity. The precise measurement of pH is presented in International Standard ISO 31-8 as follows: [ 15 ] A galvanic cell is set up to measure the electromotive force (e.m.f.) between a reference electrode and an electrode sensitive to the hydrogen ion activity when ...
Commercial reference electrodes consist of a glass or plastic tube electrode body. The electrode consists of a metallic silver wire (Ag (s)) coated with a thin layer of silver chloride (AgCl), either physically by dipping the wire in molten silver chloride, chemically by electroplating the wire in concentrated hydrochloric acid (HCl) [3] or electrochemically by oxidising the silver at an anode ...
The antimony electrode has been investigated for its ability to function as a pH electrode. [1] The electrode is made of elemental antimony. The electrochemical process can be formulated as Sb 2 O 3 (s) + 6 H + + 6 e − ⇌ 2Sb(s) + 3H 2 O. The oxide, Sb 2 O 3, is present on the surface of the electrode. Although this electrode does not give ...
Most electrodes work over a limited range of conditions, such as pH or temperature, outside of this range the electrodes behavior becomes unpredictable. The advantage of a pseudo-reference electrode is that the resulting variation is factored into the system allowing researchers to accurately study systems over a wide range of conditions.