Questions tagged [conductivity]

A material's ability to conduct electric current or thermal energy by any means.

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14k views

Electrical conductivity of graphite

On this Wikipedia page, the electrical conductivity of various materials are given in the third column ($\sigma \text{ (S/m) at 20}^\circ \text{C}$). I am interested in the entry for Carbon (graphite)...
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Choice of doping elements in semiconductors

In a typical semiconducting material, we start with silicon (group IV) and introduce atoms of group V or group III depending on whether we are constructing an n- or p-type semiconductor respectively. ...
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Conductivity as a function of acid concentration

I have conducted an experiment measuring the conductivity of both hydrochloric acid and sulfuric acid in solution respectively, with varying concentration. Wikipedia as well as a question on the site ...
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Why is it that the least reactive metals are the best electrical conductors?

Silver, Gold and Platinum are amongst the best conductors of electricity, but also the amongst the most unreactive. Since electrical conductivity depends on the number of delocalized electrons (along ...
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387 views

How does conductivity work for non-redoxed ions?

Related (very similar, but here I want a mechanism) https://physics.stackexchange.com/q/21827/7433 By the Kohlrausch law, all ions contribute to the conductivity of an electrolyte. Now, as I ...
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Does an electrically conductive gas exist at room conditions?

As I know, the gases are insulators, because their particles are mainly electrically neutral, and thus there is no movable charges in them. But maybe it shouldn't be always so, for example if a gas ...
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292 views

Is there any electronic component to water conductivity?

Answers to Decrease in temperature of a aqueous salt solution decreases conductivity indicate that the electrical conductivity of salt solutions arises from the mobility of ionic species and therefore ...
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3answers
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Why are ionic compounds bad conductors of electricity in solid state?

I understand the fact that ionic compounds are good conductors of electricity in molten state. But why aren't they good conductors in solid state. Cannot ions vibrate about their mean position and ...
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1answer
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Why are isotopically pure diamonds 50% more thermally conductive than other diamonds?

A laboratory grown type-IIa diamond (no nitrogen defects) has a lambda of $\pu{1800-2200 W/mK}$, but an isotopically pure diamond of $\ce{^{12}C}$ can have up to $\pu{3320 W/mK}$. Why are $\ce{^{12}C}...
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455 views

Why do we do electrolysis and electroplating using warm electrolyte?

This is a pretty basic question, and I know it has something to do with conductivity, but I'm not quite sure how they are related.
9
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1answer
301 views

Does the delocalization of p-orbitals ensure conductivity?

For example, polyacetylene is a conjugated system, i.e. with de-localized p-orbitals, but accroding to Chiang et. al. (1977) polyacetylene is semiconducting, and becomes conductive only when doped ...
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Why is copper a better conductor than iron?

So metals are good conductors as the electron in their outer shell is loose and can plunge out of the atom with the application of the slightest force(voltage). Silver is the best metallic conductor, ...
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How strict is the “to excite electrons the energy must equal the energy state difference” fact?

We are always told that to excite an electron from one state to a higher energy states, for example from the valance band to the conduction band, the energy must equal the energy difference between ...
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Can dust conduct electricity?

Just out of curiosity, can dust conduct electricity? The source of dust varies, is there any form of dust that can conduct electricity?
7
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How to derive the conductivity titration curve which accounts for salt formation

I derived an equation that gave me the volume of base required to get a certain $\mathrm{pH}$: In a titration between a weak acid $\ce{HA}$ and weak base $\ce{B}$ (adding base into acid solution) the ...
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Mathematical Expression for Limiting Molar Conductivity

I have been fiddling around with the theory of electrolytes, specifically molar conductivity, and ways of calculating limiting molar conductivity $\Lambda^0$. I was able to come up with the ...
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1answer
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Why conductivity of electrolyte decreases on dilution, but molar conductivity increases?

I learnt that on dilution of an electrolytic solution, it's conductivity decreases. However, there is an increase in the molar conductivity of the solution. The book explained the reason by comparing ...
6
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1answer
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If liquid hydrogen fluoride autoionises, how can it be an insulator?

According to Wikipedia, one of the last major hurdles in the isolation of elemental fluorine was the need to mix hydrogen fluoride with another substance in order for its electrolysis to be possible (...
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Conductivity measurements of demineralized water - Unexpected results. Looking for explanation

I'm trying to measure the conductivity change of demineralized water over a few days. But I get results I can't explain. Setup This is the circuit and cell I'm using: Where $R_x$ is the ...
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2answers
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What solvent would have the fewest ions?

We know that water auto-ionizes (to a rather small extent). My question is which solvent would have the fewest ions (or at least fewer ions than water). I'm thinking that perhaps some kind of ...
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342 views

Decrease in temperature of a aqueous salt solution decreases conductivity

Why does the conductivity of a water solution drop as the temperature decreases? How are these two related?
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Examples of electronically conductive foods?

There are many foodstuffs that are ionically conductive (for example, anything moist and salty). What about foods that have a high electronic conductivity? The only thing I can think of would be ...
5
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1answer
641 views

Formation of Bands in Semi-Conductors

At school, we are learning about semi-conductors and their applications in modern electronics. One of the features of semi-conductors is that there is a small energy gap between the valence and ...
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Behaviour of element 111

Is element 111 considered to act as an eka-aurum? Being under the same column of group 11, which usually provides enough evidence for correlation of properties for an eka-element, would this element ...
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1answer
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Trends for electrical conductivity?

Which element has the greatest electrical conductivity? (A) As (B) Ge (C) P (D) Sn I am unsure of how to approach this problem. Is there some sort of trend for electrical ...
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What is the difference between molar conductance and molar conductivity?

I'm learning (or at least trying to learn) about electrochemistry, but a major obstacle to that, is that different books I refer use different terms for the same symbols. So in a last ditch attempt to ...
4
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1answer
267 views

Why does the conductivity of a LiOH solution decrease when boric acid is added?

If I start with pure water and add $\ce{LiOH}$ the conductivity of solution increases. However, if I then dissolve boric acid in the same solution the conductivity falls. I would have thought adding ...
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1answer
954 views

Why do gases under low pressure conduct electricity?

In J. J. Thomson's cathode ray experiment, he used a discharge tube in order to make the gas inside conduct electricity. Why do gases under low pressure conduct electricity?
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How can I calculate the molar conductivity of a solution with multiple solutes?

I'm running an experiment mixing 2 different solutions, $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{NaCl}$ with $\pu{5 mL}$ of $\pu{0.1 M}$ $\ce{KCl}$. I am measuring the conductivity of the total solution in $\...
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What is A in the following equation

This equation describes the total current in bulk solution in a battery caused by migration in the electrolyte. Then the source says what A is: In the bulk solution (away from the electrode), ...
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1answer
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Negative Ohm reading from a Electrochemical reaction?

The purpose of my experiment is to determine which salt is the best electrolyte. The setup is a tarnished spoon (Ag2S) is placed on top of thin plastic pieces that separate it from a container coated ...
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Further reading on photoconductivity of hemoglobin

I recently ran into this paper which describe experiments that confirm that hemoglobin is photoconductive. Finding this fact as incredible, I wanted to read up more on photoconductive properties of ...
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Conductivity of electrolyte solution

I found a relationship online between the conductivity of electrolyte and current. $$i = F \sum_i z_i N_i = F^2 \left( \sum_i z_i^2 u_i c_i \right)\nabla\phi = -\kappa\nabla\phi \qquad \kappa = F^2 \...
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1answer
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Would a quarternary ammonium electride conduct electricity?

If suppose, I crystallised a quarternary ammonium electride could this conduct electricity similar to a metallic conductor? Metals have lattice atoms as charged metal ions are a sea of electrons. This ...
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3answers
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Vacuum good inside a box?

I have no clue whatsoever about Chemistry on a academic point of view. We wish to transport some goods. Let's say we vacuum some of those goods, by doing like so: We place those goods on a box, we ...
3
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1answer
912 views

Why does Ga improve conductivity of Ge?

This is for my AP Chemistry course and the question is: Which of the following elements is important in the semiconductor industry to improve the conductivity of Ge? K Ga Al Mg ...
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703 views

Are there compounds more conductive than Silver (Ag)?

Silver is the most electrically conductive element on the Periodic Table. However, I am interested in knowing if there are any compounds (combinations of elements) that would be more conductive than ...
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1answer
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Stritations in a discharge tube

I am reading about A cathode ray discharge tube and I still do not fully understand why that as you keep on lowering the pressure in the chamber it creates striations, Faraday's dark space and Crooke'...
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Can all water soluble ionic compounds conduct electricity?

I'm taking a first yer chemistry course at University, i am reading alot of contradicting things. Some people say that ionic compounds that are soluble in water are ALWAYS electrically conductive, ...
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1answer
519 views

Behavior of NaCl in water with electrodes

If I had some NaCl dissolved in water, it is conductive, so if I were to put two electrodes in the container (powered), what is causing the flow of electrons? Do the NaCl ionic bonds break and the ...
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1answer
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Finding out pKa of acid from molar conductivity

I'm reading about the electrical properties of solution where there is a problem like that: The molar conductivity of $0.0250\ \mathrm M$ $\ce{HCOOH(aq)}$ is $4.61\ \mathrm{mS\ m^2\ mol^{-1}}$. ...
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1answer
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What kind of unit is this [A*m^2/mol]?

I found a term on this website that gives a unit of [A*m^2/mol]. The equation is: $k_d^{eff}=\frac{2RT\kappa^{eff}}{F}(t^+-1)\left(1+\frac{\text{d}\ln(f)}{\text{d}\ln(c)}\right)$ where R is the gas ...
3
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1answer
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Why are metals conductive in terms of orbitals?

Back in high school I was taught a definition of metals: Metals are a lattice of positive nuclei embedded within a sea of delocalised electrons Metals are conductive because the electrons aren't ...
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1answer
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Improving copper contact and preventing oxidation

I have a model railway in which I use pure copper on the tracks and in the engine to power the train with electricity. Is there any solution to prevent the copper surfaces from corrosion, and maybe ...
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1answer
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Conductivity and Molar Conductivity of Equimolar Solutions of LiCl and KCl

If one took equimolar solutions of $\ce{Li}$ and $\ce{K}$, which would have higher conductivity? Is it the same for molar conductivity? Say, $\ce{LiCl}$ and $\ce{KCl}$, of a litre each. Also, as ...
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1answer
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What attributes cause a substance to be nonconductive or conductive

I understand what causes elements to be conductive or nonconductive. But what causes a substance say rubber to be nonconductive at a molecular level?
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What makes ionic conduction fast or slow?

Sometimes in certain electric circuits (such as in voltaic cells) ions are moved around as well as electrons. I have a basic understand of what materials (mostly metals) conduct electrons well but ...
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Graphene Vs Copper?

I was wondering about the amazing conductive properties of graphene, lets assume a large copper bar that is 10 kg, current of 1kA and probably more can flow in it, what about graphene? It certainly ...
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How well (or poorly) does natural leather insulate?

What is the general thermal conductivity of animal skin leather? I understand there are many different animal's skins (cow, sheep, buffalo, deer, pig), but in general, does natural leather insulate ...
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1answer
952 views

What is the difference between λ and Λ with regard to molar conductivity?

I came across these equations (boxed in red) in a book: $$ \begin{align} &\therefore & t_\mathrm{c} &= \frac{u_\mathrm{c}}{u_\mathrm{c} + u_\mathrm{a}}\\ &\text{and} & t_\mathrm{...