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 Corrosion and its reaction [on hold]

Tin metal is in contact with copper metal and both are put in moist air. Give the scheme of electrochemical corrosion and write equation for the reactions that occur.
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1answer
18 views

Galvanic Cells, theoritical voltage [on hold]

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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13 views

Mg/air Battery Overpotential [on hold]

A Mg/air battery discharging at a constant rate gives a cell voltage of $1.33\text{V}$. Assuming that the Mg ion concentration is $0.224M$, that the pH of the battery solution is 1.77 and that the ...
0
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0answers
11 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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0answers
15 views

What is the potential of the given Ag electrode? [on hold]

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
98 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 $\ce{Ag(s)|AgCl(s)|Cl-}$. ...
4
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1answer
35 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 ...
0
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0answers
18 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?
4
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1answer
35 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 ...
0
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1answer
41 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
65 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? ...
0
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1answer
39 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 ...
2
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1answer
22 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 $1.400\cdot10^{-1}~\mathrm{M}$ ...
1
vote
1answer
14 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 $$ ...
1
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1answer
25 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 ...
0
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1answer
34 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 ...
0
votes
0answers
18 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 ...
5
votes
2answers
84 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 ...
0
votes
1answer
24 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 ...
2
votes
2answers
111 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 ...
0
votes
1answer
70 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. ...
0
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1answer
41 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
26 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 ...
4
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1answer
141 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 ...
0
votes
1answer
43 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
65 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 ...
3
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1answer
68 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 - ...
6
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2answers
83 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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1answer
44 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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2answers
49 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 ...
4
votes
1answer
82 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 ...
2
votes
1answer
52 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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0answers
30 views

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 ...
4
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3answers
2k 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 ...
4
votes
1answer
49 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 ...
5
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1answer
1k views

Why does Zn react with NaOH?

If zinc is less reactive than sodium, then why does it still react with sodium hydroxide?
5
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1answer
108 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 ...
3
votes
1answer
81 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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1answer
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 ...
0
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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) + ...
2
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0answers
42 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 ...
0
votes
1answer
143 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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0answers
38 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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0answers
49 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 ...
0
votes
2answers
70 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 ...
1
vote
1answer
35 views

Does changing the stoichiometric coefficients affect the Nernst equation?

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} ...
6
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1answer
137 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 ...
2
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1answer
33 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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1answer
24 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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1answer
32 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.