What is the electrode potential of calomel electrode?
The electrode potential depends on the concentration of chloride ion as like silver-silver chloride electrode. It is 0.280 V at 1M KCl and 0.241 V at saturated KCl which is so often called as SCE as abbreviation of Saturated Calomel Electrode.
Why is KCl used in SCE?
The SCE has the advantage that the concentration of Cl-, and, therefore, the potential of the electrode, remains constant even if the KCl solution partially evaporates. A significant disadvantage of the SCE is that the solubility of KCl is sensitive to changes in temperature.
Why is the potential of calomel electrode is constant?
For the Silver-silver cloride reference electrode or the calomel reference electrode the potential is constant because it contains a fixed chloride concentration.
What is the variation in the potential of a calomel electrode with change in chloride ion concentration?
Answer: The potential of calomel electrode decreases with increase in the concentration of chloride ions at a given temperature. Thus, electrode is reversible with respect to concentration of chloride ions.
How is calomel electrode represented?
Calomel electrode is represented as – `Hg(l)|Hg_(2)Cl_(2)(s)|HCl(aq),` Its `E^(@)` value is `+0.24V`.
What type of 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.
Why do we use calomel electrode?
A calomel electrode is a type of reference electrode that is based on reactions between mercury (I) chloride (calomel) and elemental mercury. These electrodes are commonly used in used in voltmeters and pH meters.
Why is calomel electrode a preferred 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. It is composed of a solid paste of Hg2Cl2 and liquid elemental mercury attached to a rod that is immersed in a saturated KCl solution.
Why calomel electrode is used as 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 advantages of calomel electrode?
Advantages of calomel electrode: It is easy to set up and easily reproducible. It is convenient and easy to transport. It is very compact and smaller in size requires little space. No separate salt bridge is required as it has already a side tube containing KCl solution.
Which is the correct cell representation of the calomel electrode?
Calomel electrode is represented as – Hg(l)|Hg2Cl2(s)|HCl(aq), Its E∘ value is +0.24V.
Why calomel electrode is used?
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.
What is the potential of the calomel electrode based on reaction?
The calomel electrodeis based on the reaction The standard potential for this reaction is +0.268 V. If the cell is saturated with KCl at 25°C, the potential is +0.241 V.
What does calomel mean in chemistry?
Calomel Electrode. Definition – What does Calomel Electrode mean? A calomel electrode is a reference electrode that is based on reactions between mercury (I) chloride (calomel) and elemental mercury. The aqueous phase in contact with both the calomel and the mercury is a saturated solution of water and potassium chloride.
What is standard cell potential (E° Cell)?
The potential of the cell under standard conditions (1 M for solutions, 1 atm for gases, pure solids or liquids for other substances) and at a fixed temperature (25°C) is called the standard cell potential (E° cell ). Only the difference between the potentials of two electrodes can be measured.
What is the standard electrode potential of a galvanic cell?
overall: Zn ( s) + 2H + ( aq) → Zn2 + ( aq) + H2 ( g) Figure 6.2.3: Determining a Standard Electrode Potential Using a Standard Hydrogen Electrode. The voltmeter shows that the standard cell potential of a galvanic cell consisting of a SHE and a Zn/Zn 2+ couple is E° cell = 0.76 V.