How Do You Know Whenyou Have a Stronger Reduding Agent
Recap - An oxidizing agent is a substance which makes other to lose electrons and gains those electrons to get reduced. A reducing agent is a substance which loses electrons and get oxidized. Once this basic fact is understood, every aspect of Redox process falls in line.
It is obvious , more readily a substance loses electrons, the more powerful it is equally reducing agent. Opposite to this, the more readily a substance gains electrons , the more stronger it is as oxidizing agent.
The bones fact is ranking of oxidizing and reducing substances in terms of their strength for oxidation and reduction in a chemical reaction depends on their relative ability to proceeds or lose electrons.
Electrochemical series is a tool to predict relative ability of oxidizing and reducing agents.
What is Electrochemical series?
In simple words, an electrochemical series is an arrangement of elements in terms of their ability to acquire electrons and thereby go reduced.
The force which drive an element to acquire electrons and thereby be reduced is chosen Reduction potential of the element.
The text volume definition of Electrochemical series is " it is an organization of elements in lodge of increasing reduction potential values"
Concept of Standard reduction potential
By convention, the reduction potential or electrode potential is expressed as the potential acquired by a metallic immersed in a solution of its ions of concentration i mole / liter at 25 degc and 1 atm force per unit area and this is chosen Standard reduction potential.. Reduction potential is measured in volts (v), or millivolts (mv) and expressed equally E°. The table below is showing how oxidizing and reducing substances are arranged in an electrochemical series.
How to read electrochemical series ? Information technology is elementary and like shooting fish in a barrel.
In electrochemical series, the substances which are stronger reducing agents than hydrogen are placed to a higher place hydrogen in elevation half and have negative values of standard reduction potentials. The negative sign shows these reduction potentials are less than reduction potential of hydrogen. Below hydrogen in the bottom half, the substances which are weaker reducing agents than hydrogen are placed and take have positive values of standard reduction potentials. The positive sign of reduction potential below hydrogen shows that these reduction potentials are more than reduction potential of hydrogen. Hydrogen which comes in the middle of electrochemical serial has zilch reduction potential. Compared to hydrogen, lithium at the top of the tabular array has lowest reduction potential and fluorine at the lesser of the tabular array has the highest reduction potential. The stronger the reduction potential, the more difficult is oxidation - example is fluorine. It is difficult to oxidize fluorine. The weaker the reduction potential, the easier is oxidation- instance is lithium. Information technology is difficult to reduce lithium. Lithium is the strongest reducing amanuensis. Forcefulness of a reducing agent is a measure of its ability to lose electrons and get oxidized. Lithium has the strongest power to lose electron. Fluorine is at the lesser of the table has highest reduction potential. Information technology is the weakest reducing amanuensis or the strongest oxidizing amanuensis with everyman ability to lose electron or highest ability to gain electron and get reduced. Between lithium - strongest reducing amanuensis at top and fluorine - strongest oxidizing agent at bottom , other reducing and oxidizing substances find their place in electrochemical series co-ordinate to their reduction potential.
Ability of Oxidizing and Reducing agents
At top end of electrochemical serial there is lithium which is the strongest reducing agent and at the bottom end of electrochemical serial in that location is fluorine which is the weakest reducing agent or the strongest oxidizing agent. Therefore, as y'all become down the electrochemical series the elements become more and more oxidizing and ultimately at the lesser you accept the strongest oxidizing amanuensis which is fluorine. Similarly, as you become up the series the elements go more than and more reducing ultimately at the top yous take lithium which is the weakest oxidizing amanuensis and strongest reducing amanuensis.
What electrochemical series tells u.s.a.?
To summarize, electrochemical series tells us , the stronger the reduction potential, the more hard is oxidation and weaker the reduction potential, the easier is oxidation. Another way to express what electrochemical series tells usa, the stronger the reduction potential, the metal is more than electronegative and opposite is the weaker the reduction potential, the metal is more electropositive. We can besides say, equally yous go down the electrochemical series ability of elements to lose electron reduces. Since the action of a metallic is judged past how readily information technology loses electrons, metals in this activity serial progressively become less active and more stable as you go down the electrochemical serial. In electrochemical reactions more active metal becomes an anode and lose electrons and a less active or more than stable metallic becomes cathode and gains electrons.
Application of electrochemical series in Galvanic corrosion -What makes metals electrodes in Galvanic corrosion?
Galvanic corrosion is typically a ii metal corrosion. Information technology is an electrochemical oxidation-reduction (redox) procedure, occurs when two metals dissimilar in terms of their potential, are in electrical contact while immersed in an electrically conducting liquid. These metals with different potential become two electrodes of a electrochemical prison cell with one supplying electrons to some other as shown beneath.
Metal having lower value of electrode potential on the upper side of electrochemical serial acts as anode and oxidize (anodic reaction) and lose metallic and corrode. The reason is - a metal with low reduction potential above hydrogen in electrochemical series are more than reducing agents with tendency to lose electrons and get oxidized. The metallic having higher value of electrode potential (more noble or more stable), below hydrogen in the electrochemical series go cathode and gains electrons lost by anode and go reduced. This is a reduction reaction. The algebraic divergence between the electrode potentials of the two metal electrodes determines the driving strength for galvanic corrosion Bigger the potential departure betwixt 2 metals bigger is the rate of corrosion. This voltage divergence drives the current flow to advance corrosion of the anodic metal. Anodic metal corrosion is more rapid and more than damaging as the voltage difference between 2 electrodes increases.
When the two metals in a galvanic couple are close on the series, their voltage ranges overlap, and either one tin can be the anode, depending on the exact exposure weather.
Instance
In a typical Zn - Fe bimetallic system , Zn with electrode potential of -0.763 v compared to Atomic number 26 having electrode potential of -0.44 v with potential deviation of near 0.32 5 between Zn and Fe volition drive corrosion. Zn will deed as anode and oxidize and corrode considering Zn is more active metal than Iron, Zn = Zn2+ + 2e- (corrosion of zinc). The electrons given up by the anode will flow to the cathode (fe) where oxygen will reduce to OH- ions,
½ O2 + H2O + 2e¯ = 2OH¯
Zinc will combine with OH- ions and precipitate zinc to zinc hydroxide on cathodic surface
Zn++ + 2OH- -------- > Zn(OH)two
Zn(OH)2 becomes a bulwark layer on cathode and iron is protected.
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