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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Why would electrode reaction in galvanic cell stop when there's no neutrality in each cell?

I know that the salt bridge produces ions to balance out the positive and negative ions in each solution, but why won't it work without a salt bride? Would it even work at the start since there's few ...
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22 views

pH Indicators for Hoffman apparatus

I've read that bromothymol blue can be mixed in with the electrolyte in the demonstration of electrolysis using a Hoffman apparatus. The indicator clearly shows the local differences in pH for the ...
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126 views

Will I get bromine by electrolysis of the brine from the Dead Sea?

I know that electrolysis of a saturated solution of sodium chloride with an inert anode (eg., graphite) is a handy way to obtain pure chlorine. I have a sample of saturated salt solution from the Dead ...
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37 views

What is the meaning of electrode potential?

When we say that the electrode potential for $\ce{Co}^2$$^+$/$\ce{Co}$ is -0.28 V and $\ce{Cu}^2$$^+$/$\ce{Cu}$ +0.337 V, what is the physical meaning? Can you conceptually explain when two electrons ...
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54 views

What is the reaction between a copper anode and a zinc cathode?

I prepared a battery with Zinc screws and copper wire, with water as an electrolyte. Zinc screw being cathode and copper being anode. I got nearly 0.6 volt as emf. I placed numerous such cell in an ...
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51 views

how to measure dissolved oxygen?

How do you measure dissolved oxygen reliably in a culture of cells? This page has info on one sensor: http://water.me.vccs.edu/concepts/domeasure.html how would you know that this sensor is working - ...
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60 views

Nernst equation and electrolysis

Let's say we have a stable solution of $\mathrm{A}_{\left(\mathrm{aq}\right)}^{2+}$ and $\mathrm{C}_{\left(\mathrm{aq}\right)}^{+}$ , with their respective counter-ions. The associated redox ...
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27 views

Fractional Subscripts?

What is the physical meaning when we have an empirical formula with fractional subscripts such as $\ce{LiMn_{1-x}Fe_{x}PO4}$ (0 ≤ x ≤ 1) This is the brief paper where I saw the notation above
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33 views

Energy Calculations using VIt

The answer for Energy in kJ = $2.5 \times 3600 \times 1 = 9000 kJ$ I do not understand what formula they are using... are they using $VIt$, where $V =12$, $t= 12.5 \times 60 \times 60$ seconds and ...
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58 views

How does copper reduce dilute nitric acid to nitric oxide and concentrated nitric acid to nitrogen dioxide?

Here are the 2 equations: $\ce{3Cu + 2NO3- + 8H+ <=> 3Cu^2+ + 2NO + 4H2O}$ ${E = 0.62V}$ $\ce{3Cu + 2NO3- + 4H+ <=> 3Cu^2+ + 2NO2 + 2H2O}$ ${E = 0.45V}$ The Nernst equation tells us ...
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49 views

Electrochemical potentials

I was carrying out an experiment into the effect of temperature changes on the standard potential of a cell. $$\ce{Zn(s) +2Fe^{3+}->Zn^{2+} +2Fe^{2+}}$$ I used equi-molar concentrations of ...
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Degree of dissociation of strong electrolytes in concentrated solutions of ionic substances

Why is the dissociation of strong electrolytes complete in very dilute solutions of ionic substances but less likely to be so in more concentrated solutions? Before seeing this, I thought a strong ...
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155 views

Positive or Negative Anode/Cathode in Electrolytic/Galvanic Cell

In a galvanic (volatic) cell, the anode is considered negative and the cathode is considered positive. This seems reasonable as the anode is the source of electrons and and the cathode is where the ...
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1answer
34 views

Standard electrode potential for electrolytic vs galvanic cells

Whys is the standard electrode potential (-) for electrolytic cells but positive for (+) galvanic cells. If E°cell > 0, then the process is spontaneous (galvanic cell) If E°cell < 0, then ...
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603 views

Why does Zn react with NaOH?

If zinc is less reactive than sodium, then why does it still react with sodium hydroxide?
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36 views

Salt concentration and electrical permittivity of water

We know that the electric flux density $D$ can be related to electric field intensity $E$ as $D=\epsilon(\omega) E$ $\epsilon(\omega) = \epsilon_0 \epsilon_r(\omega) $ where $\epsilon_0$ is the ...
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71 views

Electron Transfer in Organic Reactions: Why Does Brown Iron Oxide Improve Burn Rate of Rocket Candy?

On wikipedia, this statement exists about rocket propellant aditives: Metal oxides have been found to increase the burn rate of sugar propellants. [...] Most often used are iron oxides. Red iron ...
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17 views

Detecting the concentration of chlorpromazine

Is there a way to detect the concentration of chlorpromazine in a small sample ; ex: human saliva, using electro-chemical analysis? Does the sensor necessarily have to be a bulky piece of lab ...
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1answer
22 views

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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34 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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1answer
84 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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25 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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39 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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57 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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21 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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123 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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29 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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22 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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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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2answers
135 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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37 views

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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116 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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59 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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70 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
55 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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1answer
41 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
49 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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78 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
51 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
60 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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65 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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96 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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18 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
60 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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107 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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1answer
46 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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85 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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1answer
58 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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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 ...