Metal oxide or other salt cover gradually the surface of metal which is called corrosion .
Example of corrosion is resting of iron tarnishing of silver formation of a given layer on copper and brass etc. The electron released from IMO and call Richard to another position of matter and details of Saturn in the presence of hydrogen and it is considered that hydrogen ions are obtained from H2co3 formed by dissolving CO2 in water. similarly, hydrogen ions can also be obtained by dissolving another acidic oxide of the atmosphere in water due to this reason this place acts as a cathode and the following reactions take place.
After that oxygen present in atmosphere oxidize fe2 + ion in the into F3+ ion. These F3 plus iron form a ferric oxide and seen as rust and hydrogen ion is again produced. It damage flowers breed shapes vehicles and object made up of metal especially iron we lost crore rupees every year due to corrosion.
During corrosion metal is oxidised by giving electron and forms its oxide the resting off iron takes place in the presence of water and air the chemical of origin is very complex but it can be considered as an electrochemical phenomenon when oxidation takes place at a specific position of an object made of iron then that place act as a wall and it can be represented by the following reaction.
Formation Of Salt Bridge
It completes the circuit of cell means it connect the anode and cathode solution. It maintains of anode and cathode solution price applying anion to anode solution and cation to cathode solution. It prevents the development of liquid solution junction.
Liquid-Liquid Solution Junction –
When two electrolytic solutions are directly opposite in contact with each other than there is potential at the decrease in the EMF of a cell.
Kohlrausch Law –
Kohlrausch drew a very interesting graph between molar conductivity of various electrolytic and square of concentration on the basis of different experiments for strong and weak electrolytes. Kohlrausch proposed the following formula for experimental observation on the basis of the graph.
Combination of two electrodes is known as a cell. There was a number article passages of this relation give the modified equation of mathematical basis.
Special point –
At infinite dilution that is of dissociation of an electrolyte is complete and is Ion home independently at infinite dilution the conductance of each ion is fixed and it is independent to the fact that by which iron it is associated.
Definition – According to call Rahul slow at infinite dilution the equivalent conductance of electrolyte is equal to the sum of equation conductance of its cation and anion at infinite dilution.
Method Of Prevention Of Corrosion
Corrosion is a big problem so it is necessary to prevent pollution which source money and correlation is a reason of accident many times so it should be stopped.
There are following main method for the prevention of corrosion:-
- A most suitable method of corrosion that is it that metal is prevented from direct contact of the atmosphere.
- Erosion can be prevented by coating the metal object with suitable chemical like oil, paint etc.
- One other simple method is electro planting in which a layer of ascended and easy is spotted at the metal surface by electrolytic method these layer cottage spontaneously by oxidation and or metal surface is prevented.
Observation During Cell Reaction –
In the internal circuit of cell current flow from the cathode to anode and in the internal circuit of cell current flow from anode to cathode. During cell reaction the concentration of Zn + 2 wire increase in the energy solution with while concentration of CU + 2 iron decrease in the cathode solution. The weight of the zinc rod gradually decreases while the weight of the copper rod gradually increases.
For the formation of salt please the won consultation aqua solution of salts like KCL kno3 NH4 and o3 is dissolved in agar or gelatin and field in U shaped glass tube.
It is clear from the graph that the graph of strong electrolyte is a straight line at a low concentration which can be extended to zero concentration the value of equivalent conductance 15 at the day no consideration is equivalent to molar conductivity at infinite dilution it is also clear that Lena is not obtained from weak electrolyte which cannot be extended.
Following Conclusion Are Obtained From The Graph –
Strong electrolyte like KCL na2 so4 ch3coona me except given straight line at low concentration while weak electrolyte is non-linear and this concentration so that electrolyte which given linear line are called strong electrolyte and which give nonlinear line are called weak electrolytes.
The reason of an increase in Maula conducting with dilution is an increase in the degree of dissociation or ionization of electrolyte, therefore, the value for equivalent conductivity at certain dilution at constant temperature is contained for is electrolyte because at this condition the degree of ionization is constant for each electrolyte.
Change the increase in the degree of dissociation with dilution is suitable for a weak electrolyte for strong electrolyte is it is called conductivity ratio.
When any metal rod is dipped in the solution containing some matter and then the road will be positively and negatively charged and then will be a potential difference between metal rod and metal Ion solution which is known as electrical potential.
Standard hydrogen electrode-on cell is made up of the two electrodes where is electrode is also known as a half cell oxidation takes one-half cell and reduction takes place at another half cell. The tendency of the leftover to loss or gain electron is called electrical potential the potential for electron dosing electron is called oxidation potential and for electric and electronic is called action potential relative can be the sum in electrochemical series.
Half Cell Potential
If the electroactive substance is taken in a unit actively in a half cell than half cell potential so after it is called standard half cell potential. Is cell is obtained to determine the potential of an electron in which electrode is combined with this electrode potential is called the reference electrode? The potential of the electrode of unknown potential is determined by substance Singh the potential of reference electrode from the cell potential of 10 standard hydrogen electrode is used in the form of the first type reference electrode.
A piece of a rectangular platinum coil is used with platinum in a glass tube a conducting wire is dipped in IT field with model query with form circuit platinum fall is a clause in class to which is open towards down and hydrogen gas is passed in 881-atmosphere pressure which is I am sorry by platinum oil and extra hydrogen is eliminated in the form of bubble unit concentrated HCL solution is filled in operators following equation is stabilized between observed as togas and hydrogen ion of solution at platinum foil.