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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pH Changes in primary cells

Primary Cells - pH changes during discharge Alkaline Cell: Manganese Dioxide Zinc Alkaline Cell Anode (-) $\ce {Zn(s) + 2OH^{−}(aq) → ZnO(s) + H2O(l) + ...
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25 views

Photoelectrochemical (PEC) water splitting

I'm starting to prepare for my research project on photoelectrochemical (PEC) splitting of water into H and O using (F doped) titanium dioxide as the photoanode. I've been unsuccessfully searching in ...
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55 views

Removing HCl from water

I have water contaminated with dissolved chlorine: $\ce{H2O + Cl2 <=>HCl + HOCl}$ During electrolysis, this is an issue. These are my products: $\ce{NaCl + H2O ->T[electrolysis] NaOH + Cl2 ...
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19 views

Fuel Cell Chart - Anode, Cathode, Electrolyte

Can someone please check my table to make sure I have the correct information. I am especially unsure of the parts highlighted in yellow:
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37 views

Thermodynamic dependency of the rate of reaction

On one hand, the larger is the reduction potential of the chemical reaction and the smaller is its activation energy the larger would be the rate of reaction, on the other hand the rate of a reaction ...
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49 views

How to calculate the solubility product for PbS from galvanic potential?

Knowing that at 25°C the following galvanic cell: $$\ce{Pb~|~Pb(NO_3)_2~1M~||~PbS~saturated~|~Pb}$$ shows an $\mathrm{EMF} =0,413~\mathrm{V}$, find the $K_{sp}$ of $\ce{PbS}$. My Approach This ...
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16 views

Electrochemistry concentration problem

If I take the electrodes as nickel and silver, I've according to the nernst equation that $\ce{Ni(s) + 2Ag+(aq) -> Ni^2+(aq) + Ag(s)}$ Now $E=E_{0} - \frac{RT}{2F} ...
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106 views

Scary jelly forming on zinc anodes

I'm continuing with my electrolysis experiments. Over a long time, I seek a perfect electrodes. It seems, that when you pick the right anode and cathode, it might be a lot cheaper than universal ...
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17 views

Cell Representation of a galvanic cell:

I know basic cell representations of galvanic cells and can identify the anode/cathode. But here's a weird representation that I encountered and couldn't understand it: $\ce{Pt|H{2}(g)}(1.0 ...
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19 views

Is there way to detect surface area of nanoparticle by electrochemical technique?

I want to know other than SEM is there any other technique or instrument to detect the surface area of particle esp eletrochemical way.
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26 views

Protonation of nitric acid [closed]

I found that reaction: HNO3 + 4.1633363423443E-17 H3O = NO2{+} + OH{-} Please help me understand " 4.1633363423443E-17" term.
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131 views

Determining equilibrium constant of complex cell

Question: The following galvanic cell has a potential of 1.214 V at 25 °C: ...
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What factor determines the strength of reducing agents and oxidizing agents

The best reducing agents are located at the bottom left of the periodic table(low electronegativity) and the best oxidizing agents are located at the top right of the periodic table(high ...
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113 views

Reduce chlorine gas

I have a simple electrolysis setup which uses aqueous sodium chloride as electrolyte. The problem is that, the setup makes tons of chlorine gas along with hydrogen (I only want hydrogen). I didn't ...
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2answers
50 views

Why is chloride oxidised instead of water in copper chloride electrolysis?

For the Electrolysis of Copper Chloride: Cathode: $\ce{Cu^{2+} + 2e- <=> Cu}$ Anode: $\ce{2Cl <=> Cl2 + 2e- }$ I am confused about the reaction taking place at the anode. Wouldn't ...
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1answer
62 views

What are possible side reactions for the generation of hydrogen via electrolysis?

I recently completed making a simple water electrolysis setup to generate hydrogen which uses two graphite rods from a standard AA battery. The power source is a $24~\mathrm{V}$ $6~\mathrm{A}$ ...
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1answer
47 views

What can we say about the Gibbs free energy if it decreases or not?

[Sorry if the question looks trivial but I have thought about it for days and red a number of books all with no success.] In almost every thermodynamics book that has something to say about chemical ...
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34 views

Corrosion of metals and observations in the agar medium?

I want to know which metals oxidize and which is reduced and changes in medium and observations? According to my knowledge more corrosion will take place in Zn and Fe also corrode. Then copper ...
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1answer
37 views

In a galvanic cell, why does an electrode with a higher potential “pull” the electrons from the electrode with a lower potential?

I'm doing Grade 12 Chemistry and I'm unsure of this, taking the hydrogen electorde as having a potential of 0 volts. I'll use the copper-zinc cell as an example. Just let me know if I've got the full ...
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2answers
68 views

Why put zinc solution in a galvanic cell?

In a galvanic cell with Cu and Zn electrodes, I was taught that each electrode is immersed in a solution containing it's own positive ions. I understand why you need copper ions, so they can gain ...
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Relating Thermodynamic & Transport Properties to Electrochemical discharge curve

What are the fundamental thermodynamic & transport properties that the discharge cycle of a rechargeable battery with an intercalating cathode (like Li-ion) should depend upon? The few that I ...
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2answers
44 views

Are homemade batteries a practical alternative during a blackout?

If your home lost power without warning; are homemade batteries (such as the lemon/potato variety described in this question Are homemade batteries economically practical?) a practical alternative for ...
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1answer
56 views

Electrochemistry question about equilibrium in half cell reaction

Given the following half-reactions: $\ce{Ce^{4+} + e− -> Ce^{3+}}$ E° = 1.72 V $\ce{ Fe^{3+} + e− -> Fe^{2+}}$ E° = 0.771 V A solution is prepared by mixing ...
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63 views

On spontaneity of a redox reaction

Suppose we have a redox reaction and we want to see in what direction the reaction is spontaneous. We do this by comparing the standard reduction potentials of the sub-reactions available in the main ...
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79 views

Electrochemical cell polarity and electrodes

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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17 views

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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2answers
55 views

How does a simple alkaline battery work?

The basic + - electrolyte set up. Modern batteries and the like. How exactly do they work?
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101 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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43 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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57 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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51 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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20 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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1answer
42 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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1answer
40 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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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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1answer
38 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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1answer
40 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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23 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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2answers
126 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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1answer
41 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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93 views

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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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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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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154 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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39 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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38 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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1answer
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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39 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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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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393 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 ...