The branch of chemistry that deals with the study of redox reactions and how they can be applied to generate electricity (in electrochemical cells) and to carry out non-spontaneous reactions using electricity (electrolysis).

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Electrochemical Cell Polarity

In an electrochemical cell, the anode undergoes oxidation and the cathode undergoes reduction. This means that the anode loses electrons while the cathode gains electrons. However, the anode is ...
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What happen when there is no salt bridge in microbial fuel cell?

I wonder if there is no salt bridge on microbial fuel cell, Are there have the same amount of current or none?
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90 views

Why do acids favor the oxidizer? And bases the reducer?

Simply put, why does adding acid to the cathode up the cell voltage? From what I understand, acids are proton donors. Do these positive protons attract electrons toward the cathode compartment of the ...
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37 views

Kinetic validity; redox reactions

What's the kinetic validity of the following way of balancing the above redox reaction? I've done some searching of the literature; I've never come across oxide anions being mentioned in redox ...
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43 views

Why is the water reduction of oxygen favored in acidic conditions?

The standard reduction potential of diatomic oxygen in acidic conditions is +1.23 volts. However, the standard reduction potential of diatomic oxygen in basic conditions is only +0.40 volts. Why ...
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44 views

Is this Hess's Law Electrochemistry question incorrect?

It is my understanding that to apply Hess' Law to this equation the top equation sign would be reversed and the outcome would be +0.65 V. Often the system produces incorrect answers. I was looking ...
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18 views

Can I use harvested plants to gain electric power?

I was just thinking - plants are mostly acid. Even grass is quite acid. Could you create battery cell from squashed plants (after cutting them in pieces)? How much effective would it be? Could you ...
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35 views

Reduction potential and electron affinity

Why is it that fluorine has a much greater reduction potential than chlorine, despite the fact fluorine has a lower electron affinity than chlorine? I understand that fluorine has a lower electron ...
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20 views

Why is standard reduction potential an intensive property?

My book says that Since the number of electrons lost must equal the number gained, the half-reactions must be multiplied by integers as necessary to achieve the balanced equation. However, the ...
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38 views

Is greater relative AA battery capacity at high currents indicative of greater capacity at low currents?

I originally posted this on EE.SE but might be better here: Battery showdown compared the mAh and mWh capacity of different AA batteries discharged at 200mA. Would the relative capacities of each ...
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32 views

Calculating Redox Potential; Coupled Reactions

For the reaction of silver and hydrochloric acid to form silver chloride: would the following be the correct way to couple the below two half reactions? $\ce{2Ag(s) + 2Cl^- ->2AgCl(s) + 2e^-} ...
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24 views

how does electronic conductance of a metal change with density?

The electronic conductance of a metal depends on its density.Does this mean that if we increase the density of the metal,its electronic conductance will increase?How does it happen?
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17 views

Electrolysis of Strongly Basic Water

What happens when strongly basic water is electrolyzed? I know that the electrolysis of water in strongly acidic solution involves hydrogen protons; will these protons still be involved in strongly ...
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65 views

Explanation for the reactions in a saltwater battery with zinc and copper electrodes

I am a physicist, not a chemist. I'm trying to get a basic understanding of the reactions taking place in a battery using a saltwater electrolyte with copper and zinc terminals. I'm writing a general ...
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39 views

Since aqueous acids release Hydrogen cations into the solution, will an electric current create Hydrogen gas?

I was wondering that since acids dissociate in water to make a lot of $\ce{H+}$ cations. Is it possible that introducing a supply of electrons via an electric current, would create $\ce{H2}$ gas?
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Why does increasing number of salt bridges increase voltage of electrochemical battery?

In an experiment, I set up a cell with lead nitrate (w/ lead electrode) and zinc sulfate (w/ zinc electrode), with a salt bridge containing potassium nitrate. I observed that by increasing the number ...
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18 views

Is there always a need for a salt bridge to let a galvanic cell work continuously?

I read in a book that "Sometimes, both the electrodes dip in the same electrolyte solution & in such cases we do not require a salt bridge". How is this possible?
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24 views

Water purification procedure that does not involve a flocculant of any kind?

I have read about "electroflocculation" that uses less flocculant/alum, but is there a method – no matter how expensive or impractical – that uses no flocculant at all?
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69 views

Electrolysis of Water

What is the mechanism for the electrolysis of water? I understand that hydrogen and oxygen gas are made, but how exactly does this happen when electrons are passed through water? A diagram would be ...
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29 views

Conjugate Theory and Redox

I'm trying to apply conjugate theory, which I can apply very well to acids/bases, to redox. Can you verify my logic, which I have broken down below? 1) I know that solid sodium is a strong reducer. ...
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35 views

$\ce{O^{2-}}$ Anion in Redox - Origin?

How come the oxygens transferred in redox reactions are always the $\ce{O^{2-}}$anion? For example, I have this set of rules, and the rules are implicitly referring to the $\ce{O^{2-}}$ anion, a ...
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33 views

Balancing Redox Equations with $\ce{H^+}$ or $\ce{H_3^+O}$

Is it preferable to balance redox equations with $\ce{H^+}$ or $\ce{H_3^+O}$? I think the latter, because first, the bare hydrogen proton doesn't exist in water solution. So why write down something ...
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33 views

Galvanic Element: Silver Iodide and Standard Hydrogen cell

I have to calculate the $\mathrm{p}\ce{H}$ of the $\ce{H+}$ solution with the following info: $\ce{Ag(s) | AgI(s) || H2(g)(1atm) | H+(aq) (X mol/L) | Pt(s)}$ $E=0.1\:\mathrm{V}$ Temperature ...
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53 views

How to prove that reaction is possible

I have been given task to write possible reaction equations, determine oxidizer, reducer, write corresponding electron-equations and calculate electromotive force (I do not know if that is what you ...
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130 views

How to calculate the equivalent weight or N-Factor of compound(acid, salt, base or etc) using electrolysis concept

Our sir, told us about the concept of equivalent weight using electrolysis and Faraday's Law of electrolysis. We got to know ...
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41 views

Confusion regarding specific conductivity

Is there any difference between the terms specific conductivity and conductance. If yes, please explain.
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52 views

Calculation of the standard potential E(Fe/Fe3+) from given potentials

The standard electrode potentials for the following redox couples are given as: $E_0(\ce{Fe^{2+}/Fe}) = x~\mathrm{V},$ $ E_0(\ce{Fe^{3+}/Fe^{2+}}) = y~\mathrm{V}$ What will be potential ...
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31 views

What does the slope of a Levich plot represent?

I know that the limiting current is proportional to the square root of the rotation speed, but what does the slope of the plot represent?
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17 views

How does the diffusion coefficient of a species affect the limiting current for a RDE voltammagram?

And how do I find the diffusion coefficient from a Levich plot?
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26 views

Cyclic Voltammogram - How to determine Overpotential

http://youtu.be/1f92vGOridg Clicking on the link above will take you to a video with a diagram of a voltammogram. Through my own experiments I have managed to obtain a similar diagram. However, I am ...
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2answers
65 views

Cathode + Anode + Rechargeable Battery

I'm confused by the following from http://batteryuniversity.com/learn/article/lithium_based_batteries: The cathode is a metal oxide and the anode consists of porous carbon. During discharge, the ...
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35 views

Voltaic and electrolytic cells

Why more attractive metals will be oxidized? Aren't they being reduced, because they attract and receive electrons from negative polyatomic ions? So they will be anodes, where oxidization occurs. Why ...
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35 views

Electrolysis of aqueous lead nitrate

When going through one of my chemistry textbooks, I saw that the electrolysis of aqueous lead nitrate led to oxygen being formed at the anode and lead being formed at the cathode. However, in school, ...
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40 views

What is the relationship between migration and the potential of double layer theory?

Double layer theories like that of Gouy-Chapman give the electrostatic potential $\ \phi\ $ in solution. For a symmetrical electrolyte and small potential drops $\ ...
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59 views

Activity Coefficients from Electrode Potentials

Lets say we want the activity coefficient of $\ce{Cu^{2+}}$ ions in solution. Would we simply setup one half cell of a $\ce{Cu}$ electrode in a known concentration of $\ce{CuSO4}$ and then connect ...
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29 views

Calculating molar conductance?

Ok, so the following question is given in my text book. Of the molar conductance value of $Ca^{2+}$ and $Cl^-$ at infinite dilution are respectively $118.88\times10^{-4}$ and $77.33\times10^{-4}$ ...
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38 views

how to determine the relative differences in activity between metals

I am doing a lab for school and I do not know what this question is asking. In this lab we are making electrochemical cells from different metals.
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109 views

Electrochemical half cell without redox couple

In a book about electrochemistry the situation of a cell is described of which one half cell has an "undefined thermodynamic potential" as no redox couple exists: $$ Pt/Cu^{2+}\ (0.01\ M),\ Cd^{2+}\ ...
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70 views

Deriving goldman equation

So I've been trying to follow the derivation of the Goldman-Hodgkin-Katz equation on Wikipedia (https://en.wikipedia.org/w/index.php?title=Goldman_equation ) - I can follow it through after it sets up ...
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42 views

Discrepancy in current inside an electrolytic cell

Suppose A(+)B(-) type fused salt is present in an electrolytic cell (not electrochemical cell). Let n electrons be entering the cell per second. Since each A(+) requires one electron to discharge, so ...
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74 views

Electrochemistry Question from USNCO

Given these standard reduction potentials, what is the standard reduction potential for $$ \ce{Co^{3+}(aq) +3e- -> Co(s)} $$ Given: $$ \ce{Co^{3+}(aq) + e- -> Co^{2+}(aq)} \ \ \ E°=1.82 V ...
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146 views

Why do electrons follow from Zn to Cu but not Cu to Zn in the lemon battery experiment?

In the lemon battery experiment, as I understand, both $\ce{Zn}$ and $\ce{Cu}$ meet acid in the lemon, cause $\ce{Zn}$ and $\ce{Cu}$ release electrons to form $\ce{Zn^{2+}}$ and $\ce{Cu^{2+}}$. So ...
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Electrochemistry lye quality

With the following setup: plastic container, water (impure), pencil (anode), tin foil (aluminum, cathode) and solar panels supplying electrical charge (roughly 36v at about 400-800ma), with the ...
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1answer
31 views

Electrolytic cell chemical composition during/after charging?

I have a pot with some (bottled) water and added (sea) salt. It has a pencil (graphite) and tin foil (aluminum). The pencil is connected to the positive outlet of a solar panel and the tinfoil is ...
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1answer
438 views

Half cells: difference between E(cell) = E(cathode}-E(anode) & E(cell) = E(oxidation) + E(reduction)

When do I use each of the above? If I use one or the other they give me difference results. For example, I'm trying to put the Volts into an equation to find standard free energy change. $$\Delta ...
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4answers
139 views

How could I create a machine that as rapidly as possible creates greenhouse gases from air?

For a very large-scale project, I am trying to create a greenhouse gas demonstration device, which rapidly produces greenhouse gases from atmospheric air using only electricity, or any chemical ...
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1answer
47 views

How do I work out the amount of H+ ions in a sodium hydroxide and water solution?

I know the $pH$, pressure, temperature and concentration of the solution. Is there a method I can use to work out the amount of $\ce{H+}$ ions?
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74 views

How do I derive the Nernst equation in the case in which R is absent?

Does anyone know what the intermediate calculations are to obtain equation 1.4.14? Taken from Fundamentals and Applications (Bard) page 31 To be more precise, how to obtain (1.4.14) from ...
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91 views

What is made at the copper cathode when electrolyzing water?

I just electrolyzed water with $\ce{NaHSO4 -> HSO4- <=> H+ + SO4^2-}$ with copper electrodes. At the anode this reaction happened: $\ce{Cu -> Cu^2+ + 2e-} \hspace{26 mm} E_0 = -0.34V$ ...
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Does anyone know where I can find the reaction rate coefficient and design equation for the electrolysis of brine and sodium hydroxide solution?

equation 1) $\ce{2 Cl^{–} -> Cl_2 + 2e^{-}}$ equation 2) $\ce{2 H2O + 2 e^{–} -> H2 + 2OH^{–}}$ These equations are the key reactions in the chlor-alkali process. I want to model a reactor ...