Which reference electrode is calomel electrode?
Saturated Calomel (Hg2Cl2) – The saturated calomel electrode (SCE) is the most popular reference electrode. It has a reputation of being very stable and robust. Silver/Silver Chloride (Ag/AgCl) – The Ag/AgCl reference electrode is simpler in construction than the SCE and it contains no mercury.
Which electrolyte is used in saturated calomel electrode?
The electrolyte solution in this reference system is normally a 3 M potassium chloride solution. Fig. 4.3B is the schematic of the electrode. A saturated water solution of KCl (potassium chloride) is in contact with the mercury and the mercury(I) chloride (also known as “calomel”).
Why calomel electrode is used as reference electrode?
Calomel electrode: This reference electrode consists of a mercury and mercury-chloride molecules. This electrode can be relatively easier to make and maintain compared to the SHE. This a widely used reference electrode because it is inexpensive and not as toxic as the Calomel electrode that contains mercury.
What are various types of reference electrodes?
Aqueous reference electrodes Normal hydrogen electrode (NHE) (E ≈ 0.000 V) concentration H+=1 Molar. Reversible hydrogen electrode (RHE) (E=0.000 V – 0.0591*pH) Saturated calomel electrode (SCE) (E=+0.241 V saturated) Copper-copper(II) sulfate electrode (CSE) (E=+0.314 V)
What is the function of reference electrode?
The role of the reference electrode is to provide a stable potential for controlled regulation of the working electrode potential and in doing so allow the measurement of the potential at the working electrode without passing current through it.
What are the disadvantages of calomel electrode?
Disadvantages of Calomel Electrode:
- When half-cell potentials are to be measured, compensation for potential is necessary.
- The calomel electrode cannot be used in the measurement of potentials of the cell where K+ and Cl – ions interfere in the electrochemical reactions of the cell.
What is the example of saturated calomel electrode?
The aqueous phase in contact with the mercury and the mercury(I) chloride (Hg2Cl2, “calomel”) is a saturated solution of potassium chloride in water.
What is the potential of saturated calomel electrode?
The saturated calomel electrode (SCE) The measured potential, E, of the SCE is +0.241 V (SHE) for a saturated chloride ion solution at 298 K.
Which electrode is used in she?
platinum electrode
The SHE consists of a platinum electrode immersed in a solution with a hydrogen ion concentration of 1.00M. The platinum electrode is made of a small square of platinum foil which is platinized (known as platinum black). Hydrogen gas, at a pressure of 1 atmosphere, is bubbled around the platinum electrode.
Why is potential of the reference electrode constant?
Reference electrodes maintain constant potential by the vertue of its composition. For the Silver-silver cloride reference electrode or the calomel reference electrode the potential is constant because it contains a fixed chloride concentration.
What kind of electrode is the saturated calomel electrode?
From Wikipedia, the free encyclopedia The saturated calomel electrode (SCE) is a reference electrode based on the reaction between elemental mercury and mercury (I) chloride. It has been widely replaced by the silver chloride electrode, however the calomel electrode has a reputation of being more robust.
Which is the saturated phase of calomel in water?
The aqueous phase in contact with the mercury and the mercury(I) chloride (Hg 2Cl 2, “calomel”) is a saturated solution of potassium chloride in water. The electrode is normally linked via a porous frit to the solution in which the other electrode is immersed.
What are the electrode potentials of saturated mercury?
Saturated mercury-mercurous sulfate (MMS). Table 1. Potential values of common reference electrodes. Electrode potentials can be reported in the scale of the particular secondary reference used for the measurement, or converted to the SHE scale or another common scale such as that of the SCE.
Which is the most common reference electrode for corrosion?
In corrosion studies, the most popular reference electrodes are: Saturated mercury-mercurous sulfate (MMS). Table 1. Potential values of common reference electrodes.