New answers tagged electrochemistry
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Electrolysing two salts with the same anion
When electrolysing solutions of mixed alkali metal chlorides $\ce{MCl}$, where $\ce{M=Na or K}$, the result is more or less the linear combination of results with pure salts, with deviation due ...
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What is brown/red precipitate in battery acid
You did something responsible with the acid (which is usually around 35% if memory serves) such as neutralize it to pH 7, right?
The best (and cheapest) way to neutralize sulfuric acid is with ash ...
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What is brown/red precipitate in battery acid
Lead oxides have various colors.
$\ce{PbO}$ is red or yellow.
$\ce{Pb3O4}$ is orange or red.
$\ce{PbO2}$ is brown or black.
Likely you have a mix of all of them.
BTW, this is not the safest ...
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How do I explain that voltage decreases when increasing the concentration of the cathode in a voltaic cell?
Nernst eqn says that,
$$E_c=E^o_c-\frac{0.059}{n}logQ_c$$.
Now $Q_c = \frac{products}{reactants}$
If I take the cell reaction $\ce{Zn + Cu^2+ -> Zn^2+ + Cu}$,
$Q_c=\frac{[\ce{Zn^2+}](anode)}{[\ce{...
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Carrying out electrolysis of very dilute NaCl for a long time
The redox potentials cited by Harikrishnan are all valid for ionic concentrations equal to $1$ M. As soon as these concentrations are different from $1$ M, these potentials are modified according to ...
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Why the current of double layer charging is independent of potential?
Wow thats a really old question but here is the answer: for electrochemical systems, C is a constant and I=C*(dV/dt) and dV/dt is the scan rate which scales the potential linearly (so is also constant)...
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Carrying out electrolysis of very dilute NaCl for a long time
During the electrolysis of aqueous sodium chloride solution, the products are $\ce{NaOH}$, $\ce{Cl2}$ and $\ce{H2}$ . In this case besides $\ce{Na+}$ and $\ce{Cl–}$ ions we also have $\ce{H+}$ and $\...
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What is the difference between standard Gibbs energy and Gibbs energy of formation?
Here are the two definitions again:
$$\Delta G_{Rx} = \Delta G_f^{products} - \Delta G_f^{reactants}\tag{1}$$
$$ \Delta G^o_{Rx} = \sum_i s_i \Delta G_{f,i}^o \tag{2}$$
What exactly is the difference ...
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Can a multimeter be used to measure PH?
You cannot use a multimeter to measure the solution pH. What you could do is to measure it's conductance, measuring AC current going through the solution from AC low voltage ($\le \ \pu{12 V}$) source ...
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Can a multimeter be used to measure PH?
A multimeter measures resistance, i.e., the blocking of electron (or ion) flow. A pH meter measures the voltage difference between glass-encased electrodes.
As you might realize, silica-based glasses ...
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Universal indicator solution in electrolysis
It really depends on the stability of your indicator under the electrochemical conditions you apply in your cell, like Poutnik has mentioned. And actually it is a good remark that you mention the ...
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Universal indicator solution in electrolysis
Products being obtained and indicators being changed are two independent processes. There is no universal answer if the indicator can be reduced or oxidized, as it depends on the indicator and the ...
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Acid dissociation constant from conductometric data
This answer is more about the chemistry and how the conductivity relates to the ions present, and does not show a numerical solution. For that, check the answer by Poutin.
Here is the acid/base ...
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Accepted
Acid dissociation constant from conductometric data
The molar conductivity $\Lambda_\ce{AHCl hydr}=\pu{119.4 S cm2 mol−1}$ is equivalent to the partially hydrolyzed hydrolyzed anilinium chloride, according to the hydrolysis constant.
$$\ce{PhNH3+(aq) + ...
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What is the **minimum** externally applied voltage for an electroplating setup?
Better to say the minimal, externally applied voltage.
There no minimum voltage unless you mean the trivial zero voltage. In initial stage, the iron spontaneously replaces silver ions, so there is no ...
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Find cell configuration notation for permanganate in acidic medium
Because I heard people saying that since the anode already has a solid substance (solid iodine) it's not necessary to add platinum to the anode. I digress because I think platinum is necessary for the ...
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Collapse of Butler-Volmer equation into the Nernst equation at equilibrium potential
Maybe you are confused with the concept of equilibrium potential current, which seems strange. BV equation collapses to Nernst equation when the current density is zero, i.e., is thermodynamically ...
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Where does the relation Λm=κV come from? is it experimental?
These equations are definitions:
\begin{align}
\kappa &= G \cdot \frac{L}{A}\\
\Lambda &= \frac{\kappa }{ c} = G \cdot \frac{L}{Ac}\\
c &= n/V\\
\Lambda &= \frac{\kappa V }{ n} = G \...
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