What is calomel electrode in chemistry?
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What is calomel electrode in chemistry?
The saturated calomel electrode (SCE) is a reference electrode based on the reaction between elemental mercury and mercury(I) chloride. The electrode is normally linked via a porous frit to the solution in which the other electrode is immersed. This porous frit is a salt bridge.
What is the function of calomel electrode?
Calomel is used as the interface between metallic mercury and a chloride solution in a saturated calomel electrode, which is used in electrochemistry to measure pH and electrical potentials in solutions.
Which type of the electrode is calomel electrode?
reference electrode
The calomel electrode is a reference electrode based on the reaction between elementary mercury and mercury(I) chloride. The aqueous phase is in contact with the mercury and the mercury(I) chloride (Hg2Cl2, “calomel”) is a saturated solution of potassium chloride in water.
How do we represent calomel electrode?
The calomel electrode can be represented as
- A. KCl(aq)|Hg2Cl2(s)|Hg(s),Pt.
- B. KCl(aq)|Hg2Cl2(s)|H2(l),Pt.
- C. KCl(aq)|Hg2Cl2(s)|Hg(l),Pt.
- Hg2Cl2(l)|KCl(aq)|Hg(l),Pt.
Is calomel electrode a standard electrode?
Using reference electrodes unknown potential of any other single electrode can be found out e.g. two commonly used reference electrodes are standard hydrogen electrode (SHE) and Calomel electrode.
What is calomel half cell?
A type of half cell in which the electrode is mercury coated with calomel (HgCl) and the electrolyte is a solution of potassium chloride and saturated calomel. The standard electrode potential is –0.2415 volt (25°C).
Is calomel still used?
Once the most popular of cathartics, calomel has been used in medicine since the 16th century. The recognition of its potential toxicity (because of disassociation into mercury and mercuric chloride), together with the development of superior and safer cathartics, led to a decline in its use in internal medicine.
What was calomel used for in the Civil War?
Now the one piece of medical technology during the Civil War that was actually quite beneficial to patients was Chloroform. This was an anesthetic that was invented during the 1840’s. Chloroform allowed Civil War surgeons to perform their operations without a wild-eyed screaming patient on their table.
What is calomel?
Calomelnoun. mild chloride of mercury, Hg2Cl2, a heavy, white or yellowish white substance, insoluble and tasteless, much used in medicine as a mercurial and purgative; mercurous chloride. It occurs native as the mineral horn quicksilver.
Why is calomel electrode a preferred reference electrode?
Some examples of reference cells include: 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.
What are the two main chemicals used in calomel electrode?
A saturated water solution of KCl (potassium chloride) is in contact with the mercury and the mercury(I) chloride (also known as “calomel”). Linking the electrode to the solution in which the other electrode is immersed is a porous frit, which is a salt bridge.
What is calomel electrode give the reduction reaction?
Hg2Cl2 + 2e-→2Hg + 2Cl- Reduction half reaction, which. results increase in concentration of Cl- ions. Thus, Calomel electrode is reversible to Cl- ions. The reduction potential of calomel electrode is given by.
What do you mean by reference electrode?
A reference electrode is an electrode which has a stable and well-known electrode potential. The high stability of the electrode potential is usually reached by employing a redox system with constant (buffered or saturated) concentrations of each participant of the redox reaction.
What is a standard reference electrode?
A standard reference electrode is an electrode that has a known electrical potential. A standard reference electrode has many uses, but the most common is when it is used to determine the potential of another material in an electrochemical cell.
How is the potential of the calomel electrode kept constant?
The potential of the calomel electrode depends on the chloride ion activity, but this is kept constant, and saturated, due to the present of excess Cl – in the undissolved KCl crystals. The electrode is in constant with the test solution by means of the porous frit in the bottom of the electrode, which acts as the equivalent of a salt bridge.
What is a saturated calomel electrode (SCE)?
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.