27

The best known conducting aqueous solutions are that of strong acids in water because the hydronium ion (=protonated water) has the highest electrical conductivity known today. The infinite dilution conductivity of of hydronium ion are compared below from the Book Chapter "Proton Transfer Reactions and Kinetics in Water" by Stillingerenter. The ...


17

The comment by Vikki made me dig even older papers. Since conductance (not conducitivity note that Darling is using an incorrect terminology from today's standards) is inversely related to viscosity, I thought there must a sharp change in the viscosity of sulfuric acid solution as a function of concentration. This guess is not that bad. This is from 1923 ...


15

Electric charge is transferred by physically moving charged particles around. In the case of an electric current moving through a wire (for example), the electrons are moving. In an ionic compound, the ions are locked in place. They can move around a little bit, but there is not much translational motion - the ions stay in their places on the crystal ...


15

The conductivity might be viewed relative to other electrolytes and by concentration. By concentration: Up to about 25% $\ce{H2SO4:H2O}$, conductivity increases fairly linearly with concentration, reaches a maximum at ~35%, and then drops precipitately (no pun intended)! And sulfuric acid has such "affinity" for water that oleum, or fuming ...


12

At low concentration, conductivity is proportional to concentration (a linear relationship). Each ion will have its own unique mobility, as discovered by Kohlrausch. $\ce{H+}$ has the highest mobility. As you can see in your graph the acids have higher conductivities than the salts. $\ce{OH-}$ is also highly mobile. As concentration increases, the linear ...


12

I can understand your frustration. The use of terminology is often inconsistent and confused (much to my chagrin). I think you've got the general idea, the conductance ($G$) can be defined as follows: $$G = \frac{1}{R}$$ i.e. the ease with which a current can flow. As you said, $$R = \rho \frac{l}{A}$$ one can now identify, $$G = \kappa\frac{A}{l}$$ ...


11

The trick with graphene is that a lot of its amazing properties only work when you have continuous perfect sheets of it, and making graphene like this is currently beyond us, for large scales anyways. It is true that graphene has very high electron mobility $\approx10^{5}~\mathrm{cm^2/Vs}$ at room temperature, which works out to on the order of $10~\mathrm{n\...


10

The answer to this question hinges on two key questions: What kind of dust are we dealing with? How is the dust arranged (i.e. what is your experimental setup)? Which Dust? Firstly, I'm going to assume you meant domestic dust (since there are more kinds of dust than you'd imagine). I quote Wikipedia: Dust in homes, offices, and other human ...


10

Delocalized $\pi$ orbitals do allow for mobile charges. The catch there is "allow." Just because these systems can have mobile charges does not make them conductive. Conductivity can be defined as: $\sigma = n e \mu$ where $e$ is the charge on an electron, $\mu$ is the charge mobility, and $n$ is the number of charges. In the case of $doped$ conjugated ...


8

2-Methylpropane has a $\mathrm{p}K_\mathrm{a}$ of 53 ($\mathrm{p}K_\mathrm{a}$ table). That sounds pretty non-ionic. Can't think of any common all-carbon (no substituents of any kind) liquid compounds.


8

Molar conductivity is defined as the conductivity of an electrolyte solution divided by the molar concentration of the electrolyte, and so measures the efficiency with which a given electrolyte conducts electricity in solution. It's unit in S.I. is: $$\ce{S.m^2.mol^{-1}}$$


8

I've just been doing an experiment on this, and my understanding's not that great, but as I understand it the conductivity decreases because you have a lower concentration of charge carriers in the solution. The molar conductivity increases however, because as the charged ions get further apart they interact and slow each other down less. Essentially each ...


8

This is, ultimately, a question on solid state physics rather than chemistry. Further, the OP indicates that they are in high school, which kind of limits the depth of the answer that might be useful to them. However, I will try to make a simple, yet detailed answer. As atoms are brought closer and closer together, their electron clouds overlap and interact....


8

To reiterate Ivan's comment fullerene is a bad conductor because that's what the measured properties produce as a result. The mechanism that makes it a bad conductor is that it has shorter range continuity than graphite. In graphite the carbon is made of sheets that can be as long as the sample. These sheets have fairly low conductivity, but when the ...


8

ringo makes good points in his answer. Additionally, though, the increased temperature enhances mass transfer of ions to/from the electrode surfaces by at least two mechanisms: Higher temperature results in lower electrolyte viscosity, leading to a thinner fluid dynamic boundary layer and concomitant greater mass transfer to/from the electrode surfaces. ...


8

You can't conclude that by thinking alone; some experiments are necessary. True, an electron in an electride is kinda "free", in that it isn't connected to any particular atom. But that doesn't mean it can roam the entire structure, free as the wind. In fact, it sits in a potential well formed by the neighboring ions and molecules, only the well is so wide ...


7

The reasoning here is two-fold. The solubility of most electrolytes increases with temperature, and water's ionization constant also increases with temperature. On the whole this means more ions, and thereby better conductivity.


7

I agree with the commenters that electrical conduction is very unlikely, but it's worth going through some possible mechanisms: actual solvated electrons: As others have noted, free electrons would be expected to react rapidly with protons, even in a basic solution, so this changes quickly to a scenario of sequential electron transfer between protons, so ...


6

Your carefully plotted results seem in line with this table from the Foxboro Company. Though there are references that give a simple square-root relationship, they are clearly wrong at high concentrations of many electrolytes. There is a practical guide to conductivity measurement at Conductivity Theory and Practice, which mentions: For some samples ...


6

Interestingley enough, there are papers entirely devoted to the subject of measuring the properties of living skin. The paper linked gives a value of $7 \times 10^{-4}~\mathrm{\frac{cal}{cm\, s\, °C}}$ for human skin, or in everyday units used nowadays: $0.29 ~\mathrm{\frac{W}{m\, K}}$. This is only for the dermis, the part of skin that then gets transformed ...


6

To expound on DavePhD's nice answer, molar conductivity follows Kolrausch's law, $\Lambda_m=\Lambda_m^{\circ} - \kappa \sqrt{c}$ at low concentrations, which means that extensive conductivity follows $\Lambda_m c = c\Lambda_m^{\circ} - \kappa c \sqrt{c}$ in this domain. As you've discovered this relationship breaks down at high concentration. In a loose ...


6

One of the reasons why non reactive metals are good conductors is that they are good at staying as metals. Most metals react with the atmosphere to form oxides. And the majority of oxides are insulators or semiconductors. Of course there are few exceptions to this rule. Also, just a note: calcium and iron have better conductivities than platinum.


6

It depends on what you are prepared to consider a gas and what you are prepared to consider room conditions. The gas inside all discharge lamps (fluorescent lamps and neon lamps in shop signs, for example) conducts electricity and the lamps work under normal room conditions. However, the gases are often at low pressure and are, strictly speaking, plasmas ...


6

Air at STP does conduct a tiny bit due to ionization by cosmic rays; this might even provide a path for lightning leaders. "Alex V. Gurevich of the Lebedev Physical Institute [et al] suggest that... cosmic ray... might provide a conductive path that initiates lightning." In addition, ionization-type smoke detectors use a little radioactive material (e.g. $\...


6

This questions has two parts if you look closely: Which of the following elements is important in the semiconductor industry to improve the conductivity of Ge? All of the above will improve the conductivity of $\ce{Ge}$. This is because germanium is a semiconductor which conducts electricity via the movement of holes and electrons. Since germanium is ...


6

When a current is passed through an electrolyte, a chemical reaction takes place. This alters the composition of the solution over time and you won't actually be measuring the conductivity(or conductance) of the initial solution. Since in AC current, equal current flows in both directions over a given amount of time(larger enough than time period), reaction ...


6

Decrease in temperature has two effects, both attributing to lower electrolytic conductivity: decreases the mobility of the charge carriers (e.g. $\ce{H3O+}$ and $\ce{OH-}$ for pure water); suppresses auto-ionization of water (higher $\mathrm{p}K_\mathrm{w}$), reducing the total number of charge carriers.


6

According to the Stokes-Einstein-Debye theory, and assuming the ionic composition remains constant (say for a fully dissociated salt), the main factor accounting for the response of the conductivity to temperature is the change in the viscosity of the solvent. In the SED theory the frictional drag coefficient $f$ of a charged particle is proportional to ...


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