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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offset in measuring decomposition potentials

as far as I've understood to measure the decomposition potential of an electrolyte using a galvanic cell we just put two electrodes, connect them to a battery, and vary the external potential till ...
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24 views

Ion-selective electrodes

Some ion-selective electrodes can be expensive (starting from $500). Is there any relatively inexpensive do-it-yourself alternatives that would still give very accurate results? How does one make an ...
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1answer
16 views

Electrode for methanol

Could you advice an electrode for electrophoretic deposition in methanol which won't spoil methanol and also wont be spoiled by methanol. I googled a bit and found that 1 copper, platinum and gold are ...
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1answer
950 views

Why would 1kW power supplies fail around Nitric acid (HNO3) gas?

I experienced a situation where some electrical power supplies (rated over 1kW) were exposed to nitric acid ($\mathrm{HNO_3}$) fumes at roughly 9ppm for half a day; these power supplies intermittently ...
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1answer
39 views

Principle of potentiometric titration

In potentiometric titration between Ascorbic acid and Iodine when we plot the graph between EMF with volume of iodine consumed, we get a sudden decrease in emf at equivalance point,Why? It is also ...
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1answer
35 views

Iodometric titration of copper - standard electrode potentials

Upon inspection of the standard electrode potentials for the half reactions for both $\ce{Cu^2+}$/$\ce{Cu+}$ and $\ce{I2}$/$\ce{2I-}$, it becomes apparent it should be the iodide ions that act as the ...
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1answer
35 views

Sacrificial Anodes and Pit Corrosion

I have a slab of aluminum and one part of the slab will be exposed to a very corrosive environment. If I put a sacrificial anode elsewhere on the slab will the section that is exposed still be ...
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1answer
36 views

Is there an isotope effect for diffusion of an ion through a crystal lattice?

Consider the diffusion of natural abundance $\ce{Li^{+}}$ and $\ce{{}^{6}Li^{+}}$ through a crystalline matrix, say a spinel such as $\ce{LiMn2O4}$. The two lithium ions will have the same ionic ...
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1answer
28 views

Unusual color from leaking battery. What happened?

I was removing old batteries from a camera the other day. One of the batteries had leaked something very bright blue. I have seen batteries leak before and typically the colors look a bit like a ...
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1answer
32 views

Can we make a rusting battery

Since in rusting (oxidation) of Iron, transfer of 4 electrons takes place is it possible to use this reaction under catalytic conditions to create a simple electric cell, even if it just gave a ...
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2answers
63 views

Heat given off from an electrochemical cell compared to mixing reactants

My confusion regarding the difference between the heat given off in a reaction that takes place in an electrochemical cell compared to in a beaker/appropriate container when the reactants are simple ...
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2answers
32 views

Reviving a 6 Volt lead-sulfuric acid battery

I have a 6 Volt sulfuric acid battery used to power a golf cart that has all the acid drained out, and the usual solution was to add more water to the battery however I am afraid that would not work ...
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1answer
54 views

Cell overpotential diagrams

Is there anyone who knows a book where I can find a detailed explanation of cell overpotential diagrams, like the ones shown here? Thanks in advance! Thanks in advance
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37 views

in the electrolysis of H2SO4 solution, when the concentration is increased why does the current increase even when OH- ions reduce?

During the electrolysis of $\ce {H2SO4}$, $\ce {OH-}$ ions are more reactive than $\ce {SO4^{2-} }$ ions and so they dissociate. as $\ce {OH-}$ ions dissociate, they are the negative ions that carry ...
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1answer
39 views

How to accurately calculate the electromotive force for various conditions in a salt water battery?

This question is on the same topic as this one but more complex. So, let's consider the cell with $\ce{Zn}$ and $\ce{Cu}$ electrodes inside the $\ce{NaCl}$ solution. On the $\ce{Zn}$ electrode we ...
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1answer
48 views

What causes electrons to move from zinc to copper?

Here is something that no video in youtube about electrochemistry can explain me about galvanic cells. Suppose we have $\ce{Zn}$ metal immerse in $\ce{Zn^{2+}}$ in one side, then $\ce{Cu}$ metal ...
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1answer
19 views

What is the unit of molar conductivity?

Could you explain what is unit of molar conductivity along with derivation
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39 views

What reactions can take place for the reactants $\ce{Ag/Ca^2+}$ and $\ce{Mg/Cu^2+}$?

Explain the following experiments and their results. What is their chemical equations as well? When immersing a Magnesium (Mg) chunk inside aqueous solution of Copper ions (Cu(ii)), a red-brown ...
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1answer
34 views

Why is an electropositive metal like Zinc capable of plating out?

I know that electronegative metals like copper or silver can electroplate out of an aqueous solution in electrolysis. However, I've also noticed $\ce{ZnSO4_(aq)}$ can electroplate out when ...
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1answer
46 views

Why the second ionization energy of helium is greater than the first? [closed]

maybe because the first electron has a lower energy. Why does this happen?
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20 views

Voltage across friend's lemon battery is opposite of expectation?

I'm an EE, and a friend was asking about the direction of electron flow from batteries. I explained about conventional current being the flow of positive charge carriers and told him that electrons ...
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1answer
53 views

Does concentration of salt increase or decrease rate of rusting?

I want to know whether increasing the concentration of salt, specifically $\ce{NaCl}$, increases or decreases the rate of rusting. There are conflicting theories that explain opposite outcomes: ...
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1answer
54 views

How to explain the increase in current with the increase in the concentration of responsible ions?

I have conducted an experiment wherein I have used different concentrations of $\ce{H2SO4}$, $\ce{HNO3}$ and $\ce{H3PO4}$ as the electrolytes. I filled the acid in glass tube and used a 9V battery, ...
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23 views

Current In A Circuit [duplicate]

When a battery, by performing work on a charge, moves it to the higher potential, why doesn't the charge move through the battery and return to the low potential, why does it go through the circuit?
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1answer
22 views

Galvanic Cells, theoritical voltage [closed]

This reaction proceeds in the galvanic cell: $$\ce{Zn + Pb^{2+} -> Zn^{2+} + Pb}$$ I need the equation for the half-reactions of this cell and the theoretical voltage produced by this cell if ...
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14 views

Debye Length and Ethanolic Solution

What is the Debye length of a conducting metal oxide particle immersed in a $28.7\text{mM}$ ethanolic solution of $\text{CaSO}_{4}$ at $47^{\circ}C$? Assume a dielectric constant of the medium of ...
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18 views

What is the potential of the given Ag electrode? [closed]

What is the potential of a $\ce{Ag}$ electrode (immersed in a pH 4 solution containing $4.46\ \ce{Ag}^{+}$) vs. a $\ce{Ag}/\text{AgCl}$ reference electrode? I think we use the Nernst equation for ...
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2answers
109 views

Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode

I've run into trouble on this question Predict the standard potential at 310 K for the cell constructed from the hydrogen electrode and metal-insoluble salt electrode $\ce{Ag(s)|AgCl(s)|Cl-}$. ...
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2answers
53 views

Ratios of produced gases in water electrolysis

I just did a little water electrolysis experiment at home by immerging two aluminum electrodes in water with a small amount of table salt. The voltage of the battery was 6 V. What surprised me is ...
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20 views

software modelling of 1-Ethyl-3-methylimidazolium tetrafluroborate

what are the molecular details of 1-Ethyl-3-methylimidazolium tetrafluroborate? how we can model this fluid for software analysis?
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1answer
49 views

Hydrogen electrode

Why the hydrogen gas should be bubbled continuously through the electrolyte in a hydrogen electrode? A. To keep the solution saturated with hydrogen gas B. To clear the platinum electrode C. To gate ...
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1answer
45 views

Electrochemistry (Spontaneous Reactions)

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25 celsius? Pb2+(aq) + Cu(s) Ag+(aq) + Br-(aq) Li+(aq) + Cr(s) Fe3+(aq) + Cd(s) None of the Above. ...
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2answers
87 views

Is the definition of anode and cathode failing?

We know anode=oxidation=loss of electrons and cathode=reduction=gain of electrons but in the photoelectric effect the electrons are gained at the anode and lost at the cathode of the discharge tube? ...
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3answers
97 views

Why do Electrons leave the Zinc in a Galvanic Cell

What induces electrons to leave the atoms around the part of the zinc metal in a solution to travel up along that zinc metal and above the solution, through the wire and to the copper metal and ...
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41 views

Half Cell Method of Voltage Calculation in an Electrochemical Cell

A cell consists of a copper electrode $\ce{Cu}$, in contact with $1.800\cdot10^{-2}~\mathrm{M}$ cupric ion and a platinum electrode, $\ce{Pt}$, in contact with $1.400\cdot10^{-1}~\mathrm{M}$ ...
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1answer
15 views

Cathode region in corrosion

The anode region is on the iron where the following reaction occurs: $$ Fe_{(s)}\rightarrow Fe^{2+}_{(aq)}+2\,e^- $$ and at the cathode region, the following reaction occurs $$ ...
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1answer
36 views

Is a metal hydroxide fully or partly oxidised in insufficient base?

Firstly, my question only applies to transition metal compounds with more than one hydroxide group, otherwise it would be more obvious. The reason I'm asking is in an effort to oxidise some nickel ...
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1answer
45 views

faraday laws of electrolysis

I came across this question: A quantity of electrical charge that brings about the deposition of 4.5 g $\ce{Al}$ from $\ce{Al^{+3}}$ at cathode will also produce the following volume (STP) of ...
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21 views

Nernst equation for a fuel cell when gases are stored separately

I have run some tests with a PEM fuel cell and the voltage we have found was $\mathrm{1.44V}$. Given that the standard potential for a fuel cell is $\mathrm{1.229V}$ what is causing the difference in ...
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2answers
103 views

Why the salts in a salt bridge?

Take the example of a copper and zinc galvanic cell, connected by a salt bridge of $\ce{KNO3}$. I understand how the reactions will result in positive and negative charges, and that the ions of the ...
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1answer
27 views

Mixing liquids when applying a voltage

I'm thinking in the following experiment: A) Two (non mixable (like water and oil)) liquids are going to lie in a container, in the extremes of the container there are two electrodes, those ...
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2answers
144 views

What is the oxidation number of the oxygen in BaO2

According to the book for a binary compound, first we assign the element with greater electronegativity its oxidation number (oxygen always -2 except in peroxides). So, we have -2 x2 =-2. So, each ...
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1answer
79 views

Alkaline Battery Chemistry

I'd like to understand the chemical reaction in a typical Alkaline battery a little better and how that produces a flow of electrons. I read wiki, how stuff works, and some more advanced articles. ...
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1answer
54 views

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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1answer
29 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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1answer
146 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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1answer
47 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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1answer
79 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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73 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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96 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 ...