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Unanswered Questions

947 questions with no upvoted or accepted answers
4 votes
0 answers
100 views

With two reagents common on Mars, fluorite and CO2, how would I produce carbon tetrafluoride?

The hypothetical terraforming of Mars would require the heating of the atmosphere. A commonly suggested method is the in-situ production of fluorocarbons, powerful greenhouse gases. For example, ...
4 votes
0 answers
166 views

Electrolytic reduction of nitrobenzene in differing media

In my lecture notes it is given that in a weakly acidic medium, nitrobenzene on electrolytic reduction gives aniline, which makes sense to me because there is ample H+ in the medium to continue adding ...
4 votes
0 answers
40 views

Can you give an example of an electrolytic process that has high Faraday efficiency but low energy effiency

I want a nice example to help illustrate the conceptual difference between these terms to a biologist. I found this figure which might be helpful.https://www.researchgate.net/publication/...
4 votes
1 answer
234 views

How does a silver chloride electrode (Ag/AgCl) convert the potential in aqueous solution to the wire?

I am aware of the redox chemistry that happens at the electrode surface, but I'm not sure how exactly a change in electrical potential in the solution would change the potential in the electrode?
4 votes
0 answers
111 views

How to estimate the mobility constant and the surface energy parameter in the Cahn-Hilliard equation?

As a mathematician, I want to simulate phase separations with the Cahn-Hilliard equation $$ \frac{\partial c}{\partial t} = M \Delta \bigg(\frac{\partial \mu}{\partial c} - \kappa \Delta c \bigg), $$ ...
4 votes
0 answers
445 views

Why is the relationship between molar mass and boiling point for alkanes a square root relationship?

I plotted the boiling point of alkanes against their molar mass and found the following trend: I expected the trend would be linear, since (based on my understanding of what I've learned in class so ...
4 votes
1 answer
366 views

Variation of conductance of saturated aqueous solution with temperature

The following question was asked in JEE Mains 2020: Let $C_{\ce{NaCl}}$ and $C_{\ce{BaSO4}}$ be the conductances (in S) measured for saturated aqueous solutions of $\ce{NaCl}$ and $\ce{BaSO4}$, ...
4 votes
0 answers
90 views

Linearity of electrochemical cells and electrical conductivity measurement

I've measured the output signal of a few commercially available conductivity meters and was surprised to see that the signal was typically a square wave of amplitude in the range of 1.5 to 6 Vpp (peak-...
4 votes
0 answers
237 views

What is the Gibbs free energy change of physisorption?

In most sites I find online, I see that the Gibbs free energy of adsorption is negative. But, it is also said that physisorption is a reversible adsorption, suggesting that $\delta G=0$ which ...
4 votes
2 answers
1k views

Entropy change during electrolysis of water

Consider the electrolysis of water reaction: $$\ce{H_2O -> H_2 + 1/2O_2}$$ At room temperature and atmospheric pressure, the change in enthalpy of this reaction is $\Delta H = \pu{+286 kJ mol-1}$. ...
4 votes
0 answers
84 views

Regarding Ellingham diagrams

In my textbook, the following information is given about Ellingham diagram: The interpretation of $\ce{\Delta_rG^\circ}$ is based on ${K}$ ($\ce{\Delta G^\circ = -RTlnK}$). Thus it is presumed that ...
4 votes
0 answers
214 views

How much energy is required to operate a Sabatier reactor?

I am trying to model some industrial processes and having a hard time finding information about the Sabatier reaction. The Sabatier reaction combines $\ce{CO2}$ (and possibly $\ce{CO}$) with $\ce{H2}$ ...
4 votes
0 answers
87 views

Is entropy maximum in equilibrium?

Usually, in the context of non-equilibrium thermodynamics, it is said that entropy achieves a maximum in equilibrium, so the Taylor series expansion of entropy around the equilibrium state as a ...
4 votes
0 answers
88 views

Problem interpreting CV diagram in a paper

I am an undergraduate materials science student. I am currently preparing to conduct some research over the summer on alkaline electrolyte membrane fuel cells and have been reading some papers to get ...
4 votes
1 answer
249 views

Why does the heat of formation of organic radicals and positive ions decrease with their size and degree of branching at the radical or ionic site?

I am currently studying the textbook Mass Spectrometry, third edition, by Jürgen H. Gross. Chapter 2.4.3 Bond Dissociation Energies and Heats of Formation says the following: The heat of formation ...

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