Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
Efficient Potential Gradient Development Process using Sodium Electrode during Cathodic Polarization
Pankaj Aswal1, Suyash Kumar Singh2, Gayatri Sharma3, Ashutosh Sharma4 1,2,3 Department of Electrical Engineering, Faculty Graphic Era University, Dehradun, India-248002 4Department of Chemistry, Faculty Graphic Era University, Dehradun, India-248002
Abstract: The detailed study of electrolytic takes place in the negative direction by the use of behavior of sodium in hydrochloric acid solution cathodic polarization. The various observations during cathodic polarization is done in this work. through calculations, reactions and graphs are The research on studying electrolytic properties of shown in the later part7. sodium has been done by the use of volt-ammetric In previous research work the electrolytic behavior method. The various polarization curve are shown of Ag in H2SO4 solution during anodic polarization in the following research article. is studied. The previous research focuses on studying electrochemical calculative properties of Keywords: Cathodic polarization; Electrolytic Ag has been done by the use of cyclic volt- behavior; Polarization curves; Sodium; HCl. ammetric method9,10. It was studied that complex electrochemical treatment process occur in H2SO4 1 Introduction: solution using Ag electrodes, in anodic area the Polarization is defined as the change of potential oxidation of Ag with formation of oxides and from a stabilized state when current is passed AgSO4 takes place, and in cathodic area the oxygen 1,5,7 through it. During electrolysis the alteration in the compounds and AgSO4 regenerates .In this work voltage level of an electrode, becomes nobler for an we are going to study electrochemical reaction anode, and more active for cathode, than their occurs in HCl acid solution using Na electrode3,4. reversible potentials. With reference of corrosion, In a galvanic cell as a reference cell as a mode of polarization refers to the shifting of potential away operation, where a spontaneous (Redox) reaction from the open circuit voltage (Voc ) of a system. If drives the cell to produce an electric potential, the shifting potential is in the (+ive) direction, it is Gibbs free energy (ΔG°) must be negative anodic polarization. If the shifting of potential is in represented by the following equation11. the (-ive) direction, it is cathodic polarization. For ΔG°(cell)= −nFE°(cell) all metals and alloys, cathodic polarization n ------Number of moles of electrons / mole of decreases the rate of corrosion. Cathodic protection products is the application of a cathodic polarization to a F------Faraday constant system1,2,8.The electrochemical processes involving The best way to study the electrolytic component metals, such as Na, Al, Ag to meet the demand of based upon two reaction model, as various technologies and industry of great interest extraction of various byproducts (Chemicals) in the to study. Our finding has involved Na electrodes complete process. operating in different voltage level mode. The main interest in the electro-formation and electro- reduction of insoluble Ag salts in alternate Table-1-Type of reaction electrolytes containing halides, hydroxides, etc the Voltage Reaction Type study of their electrochemistry is based mainly to E°cell > 0 Spontaneous Galvanic cell serve various commercial purposes. Lot of E°cell < 0 Non- Electrolytic cell scientific work has been done in the field of spontaneous 3 electrochemistry of sodium . In our work we have use the sodium and 2 Resultant Reactions & Graphs: hydrochloric acid in order to check the cathodic The (Na+) moves towards the negative (-ve) polarization. When electrolytic reactions takes electrode and the (Cl-) moves towards the positive place the sodium ion move towards the cathode an (+ve) electrode. The resultant mixture at the 5,6 the chloride ions move towards the anode .Here cathode is:- we have tried to show how the shifting of potential
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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
Cathode (-): Reaction Reduction + - o Na + e Na E red = -2.71 V - - o 2 H2O + 2 e H2 + 2 OH E red = -0.83 V The by product at the cathode is hydrogen gas, collected and stored for other commercial and industrial purposes. - - Cathode (-): 2 H2O(l) + 2 e H2(g) + 2 OH (aq) There following substances oxidized at the anode - are Cl ions and H2O molecules. Anode (+): Reaction Oxidation - - o 2 Cl Cl2 + 2 e E ox = -1.36 V
+ - o 2 H2O O2 + 4 H + 4 e E ox = -1.23 V
The output product of above given reaction is Cl2.
o 2 At first, it seems easier− to oxidize− water (E ox = - 2NaCl aq + 2H O + − - 2 o 1.23 volts) than2C Cll ions→ Cl (E+ox 2e = -1.36 volts). It is As per the growing→ demand2Na aq of+ chlorine2OH aq with not beneficial but however, that the cell is never respect to sodium, electrolysis+ H2 g + of Cl aqueous2 g NaCl is permitted to reach basic standardize conditions. of great importance to create a product which is The solution is critically 25% NaCl by mass, useful commercially. Electrolysis of an aqueous however decreasing voltage level required for NaCl solution produces H2 gas at the cathode. it oxidization of the Cl- ion. The pH value of the also produces NaOH, which can be drained from generating source is kept high voltage level, which the bottom of the electrolytic cell. declines with the oxidation potential for H2O. The deciding factor is a technique known as higher − 2 voltage, which is the additive voltage that is 3Cl Results g + 2O H aq − − necessary to be applied to a reaction to get it to The standard electrode→ Cl potential aq + OC (El°) isaq the + measure H2O l occur at the rate at which it would occur in an ideal of individual potential of a reversible electrode in system9,8,2,1. electrochemistry at STP condition with solutes at In conclusion, electrolysis of aqueous solutions of an effective concentration of 1 mol dm−3 and gases NaCl doesn't give the same products as electrolysis composition at a pressure of 1 atm. The reduction of molten NaOH. Electrolysis of molten NaCl potential are mostly often tabulated at 25 °C. the decomposes this compound into its elements7,8. galvanic cell is always a (Redox) reaction which Electrolysis can be broken down into two half-reactions in electrochemical cell and due to potential Gradient Electrolysis of aqueous NaCl solutions gives a difference between two electrodes as a generation 2 mixture of2NaCl H2 and l Cl→2 2Na gas andl + an2C l aqueous g NaOH of electricity. This potential gradient is developed solution. as a result of the different voltage levels between the two metal electrodes with respect to the electrolyte.
Metal Results
Metal-1 Metal-2
Metal-1 The ionization potential of The ionization potential of copper is Zinc(Zn) an isolated zinc atom is only 7.723V. Metal-2 9.391V. Copper less in compare to that of Copper(Cu) Zinc holds on to its Zinc. electrons more firmly
The zinc is at a voltage of -0.761V with respect to The oxidation potential is the negative of the that of hydrogen electrode, as the reduction reduction potential, 0.761 V in this case. The more potential of the cathode reaction Zn++ + 2e- → Zn.
Imperial Journal of Interdisciplinary Research (IJIR) Page 1187
Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017 ISSN: 2454-1362, http://www.onlinejournal.in negative is the reduction potential, the more is the reduction reaction in other words either direction. Copper(Cu), Hydrogen(H) The single electrode potential for The hydrogen (H) electrode will the reaction Cu++ + 2e- → Cu behave as the anode. comes out to be 0.344V That is, it is below hydrogen, will act as a cathode.
The galvanic cell potential from a pair of basis of above table it can be concluded that the electrodes as one empirical value is available in a result of cathodic polarization is much better in pair of electrodes. A reference electrode, standard case of the cathodic polarization of sodium metal. hydrogen electrode (SHE) is set to 0.00 V and any Which can be better inferred from the above graphs electrode of unknown electrode potential is can be drawn below. paired with (SHE) to form a galvanic cell. On the
Design-Expert® Sof tware Factor Coding: Actual Desirability Voltage (volts) All Responses 27 27 Design Points 0 -2.5 -2.7 24 24
-2 Voltage (v olts) = -1.4 21 21 Std # 9 Run # 9
X1 = A: Cathodic(red) = -1.8 X2 = B: Time = 13 18 18 -1.5 Desirability 1 Prediction -1.4 15 15 5 5 12 12 B: (hrs)Time B: Time (hrs) 8.9 8.9
-1 6 6
3 3
0 0 -2.7 -2.2 -1.8 -1.3 -0.83 -2.7 -2.2 -1.8 -1.3 -0.83
A: Cathodic(red) (voltage) A: Cathodic(red) (voltage)
Optimize Reduction Equation (Mathematical) Optimize equation based upon the positive buildup of voltage with the negative time span. Voltage (Z)=-0.43394+0.14823*X-0.11701*Y-0.037512*X*Y X= Cathodic (red) Y=Time Response Intercept A B AB
Voltage -1.3745 -0.333164 -0.678192 -0.4725 p= 0.0230 0.0002 0.0164
Legend p <.01 .01<= p <.05 .05<= p <.10 p >=.10
Imperial Journal of Interdisciplinary Research (IJIR) Page 1188
Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
Table - Various factors and Responses
Factor 1 Factor 2 Response 1
Run A:Cathodic(red) B:Time Predicted Voltage voltage hrs volts
1 -1.8 32 -2.5 2 -0.44 13 -1.7 3 -2.7 27 -0.83 4 -1.8 13 -1.9 5 -1.8 -5.6 0 6 -0.83 27 -2.7 7 -1.8 13 -1.4 8 -0.83 0 -0.83 9 -1.8 13 -1.4 10 -2.7 0 -0.83 11 -2.7 13 -1.4 12 -1.8 13 -1.3 13 -1.8 13 -1.2 The reaction Na+(ion) + e- (recombination) → Na reduction potential (as highlighted in above table in has an electrode potential of -2.71V, and predicted italics). When we apply an external voltage of optimize value after 13 hrs of discharging is -1.8V greater than 1.229V, with the oxygen side positive - - while the reaction Cl2 + 2e (recombination) → 2Cl (+ve) and the hydrogen side negative (-ve), then the has an electrode potential of 1.3583V and the oxygen side acts as the anode and the hydrogen predicted value is -1.3V after 13 hrs having the side as the cathode.
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Imperial Journal of Interdisciplinary Research (IJIR) Vol-3, Issue-4, 2017 ISSN: 2454-1362, http://www.onlinejournal.in
Conclusion In the present scenario the growing demand of Chlorine higher than the demand for sodium, electrolysis of aqueous NaCl is a more important process commercially. The produced H2 gas at the cathode can be easily collected and sold. In this paper we had tried to show that the cathodic polarization of Sodium metal is very much efficient in compare to any other polarization. We had also demonstrated in the result that how the change in the voltage from -1.2 to -2.7 makes the result more and more good and appropriate.
Acknowledgement The author acknowledges Graphic Era University for the valuable support.
Reference [1] Ibrahim, M.A.M.; Hassan, H.H.; Abdel-Rehim S.S. & Amin, M.A. J. Solid State Electrochem, 1999, 3, 380 [2] Hassan, H. H; Ibrahim, M.A.M; Rehim, S S; Mohammed,A.E; & Amin,M.A. Int. J. Electrochem. Sci., 2010, 5, 278 – 294 [3] Guoqiang, Zhou; Wenying, Wang. Oriental J. Chem., 2012, 28, 2, 651-655 [4] Bayeshov, A.; Tuleshova, E.; Tukibayeva, A. Oriental J. Chem., 2013, 29, 1, 33-37 [5] Beck, R.Y., Shuraeva, L.I., et al. Electrochemistry. 2007, 43, 3, 305-312 [6] Sherif, E.S.M; Erasmus, R.M; Comins, J.D;. Electrochimica Acta, 2010 - Elsevier [7] Grossi. M; Di Lecce. G; Gallina .T.T; Riccò. B; 2014 ;.IEEE Sensors J 14 ,9 , 2947–2954. [8] Kozin, L.F.; Daniltsev, B.I. J. Phys. Chem., 2003, 77, 12, 2158-2164 [9] Grossi.M; Di Lecce, G; Gallina T.T; Riccò.B; 2014 ;.Microelectronics J 45,1701–1707. [10] Barba, Fructuoso; Batanero, Belen ;2004. The Journal of Organic Chemistry 69 (7): 2423–2426 [11] Raimann, P. R; Hochgatterer, N. S; Korepp, C; Möller, K. C; Winter. M;Schröttner. H; Hofer. F; Besenhard, J. O; Ionics –Springer December; 2006, 12, (4), pp 253-255
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