Electrochemistry Notes 12th Class Pdf

Class 12 Chemistry Notes Chapter 3 Electro Chemistry

Usually concern ration of electrolyte solution is expresses as C gm equivalent per litre. Conductors Substances that allow electric current to pass through them are known as conductors. Electromotive Force emf of a Cell It is the difference between the electrode potentials of two half-cells and cause flow of current from electrode at higher potential to electrode at lower potential. If the electrodes are reactive then they will take part in chemical reaction and products will be different as compared to inert electrodes.

Electrochemistry class 12 Notes Chemistry

The entire chapter of electrochemistry has been divided into two articles. Even if you wish to have an overview of a chapter, pc-based instrumentation concepts and practice pdf quick revision notes are here to do if for you.

The two gases formed at the cathode will build up pressure and could cause the cell to rupture. The cathode is a paste of mercuric oxide HgO and carbon powder. In this half cell, a metal coated with its insoluble salt is in contact with a solution containing the anion of the insoluble salt.

The equilibrium reaction that occurs at the electrode is. The current flowing through an electrolytic solution is carried by the ions. When one of the reactants is completely consumed, the cell will no longer generate a current.

Class 12 Chemistry Notes

Reference Electrode The electrode of known potential is called reference electrode. Debye-Huckel Onsagar equation It gives a relation between molar conductivity,? In the electrolysis process we have discussed above, we have taken molten salt as electrolyte, which contains only one cation and anion.

The solution remains neutral on both sides. Let n, faraday charge is taken out from a cell of e.

From this the specific conductivity of conductivity water is deducted. An advantage of voltaic cells is that they are small and portable, but their size is also a limitation. Daniell Cell An electrochemical cell of zinc and copper metals is known as Daniell cell. Greater the reduction potential of a substance, oxidising power. At the present time alkaline batteries are used the chemistry of alkaline cells is quite similar to that in a LeClanche cell, except that the material inside the cell is basic alkaline.

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Metallic Conductors or Electronic Conductors Substances which allow the electric current to pass through them by the movement of lectrons are called metallic conductors, e. Secondary or Rechargeable batteries An automobile battery-the lead storage battery - is probably the best-known rechargeable battery figure. In such a half cell, an inert collector of electrons, platinum or grphite is in contact with gas and a solution containing a specified ion. Thus, the net reactions may be summarised as.

Class 12 Chemistry Revision Notes for Chapter 3 - ElectrochemistryElectrochemistry Class 12 Notes Chemistry

The wire is sealed into a glass tube. Hence extrapolation in this case is not possible. It depend upon the nature of electrolyte being electrolysed and the nature of electrodes. In case of weak electrolytes, the degree of ionisation increases dilution which increases the value of?

It is also known as the primary voltaic cell and consists of a zinc container which acts as an anode and carbon graphite rod as a cathode surrounded by powdered manganese dioxide and carbon. The dilution decreases such attractions and increase the value of? Amount of substance deposited or liberated at an electrode is directly proportional to amount of charge passed utilized through the solution.

The rusting of iron, tarnishing of silver surface, the surface of copper and bronze turning green are some of the examples of corrosion. In general, for a redox cell reaction involving the transference of n electrons. First law The amount of the substance deposited or liberated at cathode directly proportional to the quantity of electricity passed through electrolyte. An electrochemical cell consists of two electrodes metallic conductors in contact with an electrolyte an ionic conductor.

The platinum electrode is easily poisoned by traces of impurities. At equilibrium, cell potential Ecteell becomes zero. The cell reaction is of redox kind. It depends upon the nature of solvent and temperature. Cathodic Protection A more sophisticated strategy is to maintain a continual negative electrical charge on ametal, so that its dissolution as positive ions is inhibited.

We are not responsible for any type of mistake in data. The cell potential is the difference between the reduction potential of cathode and anode.

These notes will certainly save your time during stressful exam days. The revision notes covers all important formulas and concepts given in the chapter. It is also expressed in Siemens denoted by S.

Electrochemistry Class 12 Notes Chemistry

Many metals such as Na Mg, Al are produced by electrochemical reduction of their respective cations on a large scale where no suitable chemical reducing agents are available for this purpose. Conductance G It is the ease of flow of electric current through the conductor. Since both the cathodic and anodic steps must take place for corrosion to occur, prevention of either one will stop corrosion. Oxidation potential The tendency to lose electrons in the above case is known as oxidation potential. However for liberation of gases, some extra voltage is required than the theoretical value of the standard electrode potential.

Daniel cell, dry cell, mercury cell. An electrode is made by dipping the metal plate into the electrolytic solution of its soluble salt.

Strong electrolytes The electrolytes that completely dissociate or ionise into ions are called strong electrolytes. How to Predict the Products of Electrolysis? This can be done by barrier protection through coating of paints or electroplating.