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So I've been trying to follow the derivation of the Goldman-Hodgkin-Katz equation on Wikipedia (https://en.wikipedia.org/w/index.php?title=Goldman_equation ) - I can follow it through after it sets up the initial model.
However, I'm having trouble using the Einstein-Stokes relationship to derive the initial model in... |
What is this wave function in Chemical bonding? |
Looks like a classic to me. But since this is homework, I will not provide a full reaction scheme and only give some hints.
1. Your starting material is a $\beta$-ketoester (1,3-dicarbonyl compound).
- Where is the most CH-acidic position in this molecule?
- Benzylchloride is an alkylating agent. What will hap... |
Looks like a classic to me. But since this is homework, I will not provide a full reaction scheme and only give some hints.
1. Your starting material is a $\beta$-ketoester (1,3-dicarbonyl compound).
- Where is the most CH-acidic position in this molecule?
- Benzylchloride is an alkylating agent. What will hap... |
Hi does anyone knows how to solve this question?
A tricarboxylic acid H3A has three different types of Pka (Pk1=2.0, Pk2=5.0 and Pk3=8.0)
Identify the ratio of the three charged components(H2A-,HA2- and A3-) in 0.2M solution of tricarboxylic acid H3A.
I managed to get 0.04M/L for the H2A- but i do not know h... |
I've always been told in chemistry lessons that lone pairs repel more due to a greater charge density than bonding pairs. And that makes sense when steric effects are involved when bond orbitals overlap. But this conflicts with what I have learnt in Physics i.e. Coloumbs Law which states that the only thing affecting t... |
Hi does anyone know how to solve this question?
> A tricarboxylic acid $\ce{H3A}$ has three different types of $\text{p}K_\text{a}$ $\left(\text{p}K_\text{a, 1} =2.0,\; \text{p}K_\text{a, 2}=5.0,\; \text{p}K_\text{a, 3}=8.0 \right)$.
> Identify the ratio of the three charged components($\ce{H2A-}$,$\ce{HA^{2-}}... |
I know that C<sup>-4</sup> + O<sup>-2</sup> = C<sub>2</sub>O<sub>4</sub> (using valency criss cross) which is CO<sub>2</sub>. But it says in my textbook that C + O<sub>2</sub> is also CO<sup>2</sup> so how is this possible? Surely this can't mean that C + O is the same as C + O<sub>2</sub>. One conclusion might be that... |
C + O = CO<sub>2</sub> . This is because carbon has valency of 4 while oxygen has valency of 2. When they react the valencies are criss crossed which means we will get C<sub>2</sub>O<sub>4</sub> but this is simplified to CO<sub>2</sub>.
But my textbook say that C + O<sub>2</sub> = CO<sub>2</sub>.
So how is it p... |
Hi does anyone know how to solve this question?
> A tricarboxylic acid $\ce{H3A}$ has three different types of $\text{p}K_\text{a}$ $\left(\text{p}K_\text{a, 1} =2.0,\; \text{p}K_\text{a, 2}=5.0,\; \text{p}K_\text{a, 3}=8.0 \right)$.
(a) > Identify the ratio of the three charged components($\ce{H2A-}$,$\ce{HA^{2... |
Hi does anyone know how to solve this question?
> A tricarboxylic acid $\ce{H3A}$ has three different types of $\text{p}K_\text{a}$ $(\text{p}K_\text{a, 1} =2.0,$ $\text{p}K_\text{a, 2}=5.0,$ $\text{p}K_\text{a, 3}=8.0)$.
> 1. Identify the ratio of the three charged components($\ce{H2A-}$,$\ce{HA^{2-}}$ and $\c... |
As far as chemistry goes, there are laws or observations that can be useful to determine the perfect shape and disposition of the wood in a campfire ?
For example what chemistry says about the 2 most popular "shapes"
- teepee ![enter image description here][1]
- log cabin ![enter image description here][2]
... |
For my chemistry experiment, I was assigned to produce Ammonia Sulfide and test the chemical properties of the compound. From my online research, I found out that I can mix household ammonia and match heads to produce Ammonia Sulfide. I think this will satisfy the purpose of my assignment, but I have a few concerns. I'... |
Is this reaction safe? |
$$ \ce{NH4(l) + S(s) -> (NH4)2S(aq)} $$
Upon mixing ammonia with potassium chlorate:
$$ \ce{NH4(l) + KCl(aq) -> NH4ClO4 (aq)} $$
Upon mild heating ammonium perchlorate decomposes:
$$\ce{2 NH4ClO4(aq) -> Cl2 (g) + N2(g) + 2 O2(g) + 4 H2O(l)} $$
As you may already be aware, chlorine gas is toxic.
$$\ce{... |
I can't seem to remember. I know that they all want to fill their valence shells, but, aren't these different? |
Do Lithium and Beryllium want to lose electrons to be like Helium? |
$$ \ce{NH4(l) + S(s) -> (NH4)2S(aq)} $$
Upon mixing ammonia with potassium chlorate:
$$ \ce{NH4(l) + KClO4(aq) -> NH4ClO4 (aq)} $$
Upon mild heating ammonium perchlorate decomposes:
$$\ce{2 NH4ClO4(aq) -> Cl2 (g) + N2(g) + 2 O2(g) + 4 H2O(l)} $$
As you may already be aware, chlorine gas is toxic.
$$\c... |
I found this recipe on how to make a stink bomb: http://chemistry.about.com/od/chemistryhowtoguide/a/Stink-Bomb-Recipe.htm
The recipe basically says to mix ammonia and match heads to create ammonium sulfide. However, I am skeptical, because
1. It seems that match heads have mostly phosphorus, and only a negligi... |
This is from a study guide for an exam coming up.
So the Question is:
>Use activities to calculate the pH of each of the following solutions, being sure to use $\alpha$ values and the extended Debye-Huckel equation.
>The first one the concentration is $0.020 M$ $NaCl$
with the answer being : $pH$ = $6.99$
... |
This is from a study guide for an exam coming up.
So the Question is:
>Use activities to calculate the pH of each of the following solutions, being sure to use $\alpha$ values and the extended Debye-Huckel equation.
>The first one the concentration is $0.020 M$ $NaCl$
with the answer being : $pH$ = $6.99$
... |
I found <a href="http://chemistry.about.com/od/chemistryhowtoguide/a/Stink-Bomb-Recipe.htm">this recipe</a> on how to make a stink bomb:
The recipe basically says to mix ammonia and match heads to create ammonium sulfide. However, I am skeptical, because
1. It seems that match heads have mostly phosphorus, and o... |
Would this recipe on stink bomb work? |
I know, by nature, normally atoms are stable. But I wonder, if it is possible to compress an atom, say the Hydrogen atom, to infinite density by applying external force? *After all, electrons and protons would attract each other by electrostatic forces and nuclear forces are also there atleast upto a certain distance..... |
Is it possible to compress an atom to infinite density? |
I know, by nature, normally atoms are stable. But I wonder, if it is possible to compress an atom, say the Hydrogen atom, to infinite density by applying external force? *After all, electrons and protons would attract each other by electrostatic forces and nuclear forces are also there atleast upto a certain distance..... |
In fact there are many types of matches so you should be aware of what you are using. In home-made experiment the problem is that many times you don't know the composition or the concentration of your reactants.
Take a look a [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.go... |
Thanks a lot Michiel I got the answer in the Fischer-Tropsch process. During normal atmospheric pressure the following reaction occurs :
$$\ce{CO + 3H2 <=> CH4 + H2O}$$
Also could someone tell me the type of reaction this is? I think it is partially a displacement reaction for O is displaced by H and gives CH<s... |
In fact there are many types of matches so you should be aware of what you are using. In home-made experiments the problem is that many times you don't know the composition or the concentration of your reactants.
Take a look a [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.g... |
Not all the matches have sulfur but only some types in [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.google.it/books?id=370UwG8CuNwC&pg=PR7&dq=match+composition&hl=it&sa=X&ei=JIM6U5ibNKaR5ASd1oGQAQ&ved=0CDIQ6AEwAA#v=onepage&q=match%20composition&f=false) see page 191, you can ... |
I have some [plastic optical fiber](http://en.wikipedia.org/wiki/Plastic_optical_fiber), which consists of a thin core of PMMA (polymethyl methacrylate), covered by a fluorinated polymer.
I would like to heat a bundle of these fibers to ~130 degrees, in order to form a simple [image guide](http://i-fiberoptics.com/p... |
PMMA melts at 160 °C and ignites in air at 460 °C, forming CO and formaldehyde as toxic gases when burning. Since you are working with a much lower temperature, PMMA should be safe. What type of fluorinated polymer do you want to use? |
I know that the mass of Helium-4 is slightly less than the mass of 2x Deuterium it may be made of and that it is the reason fusion gives a lot of energy.
But where exactly is this missing mass taken from? Aren't those 2 protons, 2 neutrons and 2 electrons forming Helium-4 atom the same as they were in previous Deute... |
What exactly happens to mass during deuterium fusion? |
I want to use syringe pump to pump water at 0.82 ml/min for 30 min ? Is that possible ( I read some paper use that but don't know how ?)
|
In fact there are many types of matches so you should be aware of what you are using. In home-made experiments the problem is that many times you don't know the composition or the concentration of your reactants.
Take a look a [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.g... |
Testing for contamination of the ever so popular [glyphosate][1] based herbicide "Roundup" in water is a service that many labs provide, one of them is the [Microbe Inotec Laboratory][2] . They use an enzyme to check for levels of of contamination in ppb, which, I'm sure, is rather a complicated process.
My question... |
The mistake is in the charge $q$, that you have put in:
$
D_A=\frac{\mu_{q}k_BT}{q}
$
$q$ is simply the particle charge (and not the whole charge, as you've unfortunately considered) and should then be expressed as:
$q=\frac{zF}{N_{A}}$
with $F$ the Faraday constant (charge / mole ), ${N_{A}}$ the Avogadr... |
The mistake is in the charge $q$, that you have put in:
$
D_A=\frac{\mu_{q}k_BT}{q}
$
$q$ is simply the particle charge (and not the whole charge, as you've unfortunately considered) and should then be expressed as:
$q=\frac{zF}{N_{A}}$
with $F$ the Faraday constant (charge / mole ), ${N_{A}}$ the Avogadr... |
Let's first look at ionic strength:
Ionic strength is a measure of the total ion concentration in solution, however, species with higher charge can also have elctrostatic interactions with other species.
$$\mu = \frac{1}{2} \Sigma C_iZ_i^2 $$
What is the strength of 0.02 M NaCl solution?
$$\mu = \frac{1}{2}... |
Let's first look at ionic strength:
Ionic strength is a measure of the total ion concentration in solution, however, species with higher charge can also have elctrostatic interactions with other species.
$$\mu = \frac{1}{2} \Sigma C_iZ_i^2 $$
What is the strength of 0.02 M NaCl solution?
$$\mu = \frac{1}{2}... |
Let's first look at ionic strength:
Ionic strength is a measure of the total ion concentration in solution, however, species with higher charge can also have elctrostatic interactions with other species.
$$\mu = \frac{1}{2} \Sigma C_iZ_i^2 $$
What is the strength of 0.02 M NaCl solution?
$$\mu = \frac{1}{2}... |
One problem is bonding of the bundle. The contact surface is the fluororesin cladding that allows more nearly perpendicular rays to be totally internally reflected. If you nick the cladding you get a light leak. Will the cladding fuse when heated?
If you ligthly bond a bunch of cylinders you get air gaps where th... |
Chemistry says that we are are we supposed to heat boiling flasks, and not Erlenmeyer flasks. However, I can't find any information about this on Google. Is there a particular reason for this?
Is it just because we want to separate the purposes for our glassware, or is there an actual valid reason? |
Why are we not supposed to heat Erlenmyer flasks? |
For a fluid flow experiment I am using DMSO (dimethylsulfoxide), because of its low volatility, reasonably high surface tension, low viscosity and relative safety.
In the MSDS of DMSO I find that the liquid is hygroscopic, meaning it adsorbs moisture from the surrounding environment. Unfortunately, I cannot find any... |
Hygroscopic behaviour of DMSO - how bad is it? |
If I get a pure solution of an acid chloride and place a pH meter into the liquid, will I get a reading of pH 7?
When I add water to it, I know $HCl$ gas will form but will this gas dissolve in water to give an acidic solution.
My main confusion is that we call ethanoyl chloride as an "acid" chloride... but is it... |
Acid chlorides... are they really acidic? |
Evaporating cold aqueous chromium(III) chloride produces violet crystals. However when hot aqueous chromium(III) chloride crystallizes, green crystals result.
Could someone please explain the chemistry behind this... I mean both the crystals contain $Cr^{3+}$, so the difference in colour cannot be due to two differe... |
Is there such a thing as a completely pure solution ? Would there not always be some water contamination and hence would you not always have some protons floating around ?
However, as a thought experiment I imagine that in a solution of 'pure' ethanoyl chloride you would have a pH of 7 as there are no free protons ... |
Given a mixture of: a saturated solution of a solute in a solvent together with excess of the solute compound as crystalline material.
If one were to change the bulk composition of the mixture by removing some of the solution could this cause dissolution or precipitation of the solid in the remaining mixture, or th... |
> If one were to change the bulk composition of the mixture by removing some of the solution [...]
This does not change the composition of the solution above the solid. Since the concentration of the solute remains constant, I do not expect a change.
> Presumably one should expect some crystallisation in the port... |
If we take **Phenloic ion**(C6H5O-)And **Acetate ion**(CH3COO-) which one would be more stable ?
I know Acetate would be more stable because it has two equivalent resonating structure.my question is why having equivalent resonating structure gives more stability???
|
In [Essential Environmental Science: Methods & Techniques
by Simon Watts,Lyndsay Halliwell](http://books.google.it/books?id=k4jjq5s6vZsC&pg=PA231&dq=should+not+heat+Erlenmeyer+flasks&hl=it&sa=X&ei=aSc8U9PQM8TI4AT6moDIAw&ved=0CFUQ6AEwBA#v=onepage&q=conical%20flask&f=false) I've found this:
)
A more sophisticated material is $\ce{LiSrPO4:Eu2+, Pr3+}$ you can read th... |
Yes, there are some minerals that shows VIS-NIR luminescence here a couple:
- Synthetic ruby $\ce{Al2O3:Cr}$
- Kyanite ($\ce{Al2SiO5}$)
([Reference here](http://www.viewsfromscience.com/documents/webpages/led_fluorescence_p2.html))
A more sophisticated material is $\ce{LiSrPO4:Eu2+, Pr3+}$ you can read th... |
In fact there are many types of matches so you should be aware of what you are using. In home-made experiments the problem is that many times you don't know the composition or the concentration of your reactants.
Take a look a [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.g... |
How can we identify bases and acids by their chemical formulas?
|
How can we identify bases and acids by their chemical formulas?
Take for example this reaction. I know that HNO3 is an acid and KOH is a base, but if I didn't know that how would I be able to identify that using the chemical formulas
HNO3(aq) + KOH(aq) ® KNO3(aq) + H2O(l) |
What type of double displacement reactions can form a gas. How can i determine if a double displacement reaction will form a gas? |
Look at The Periodic Table. Metal (Group I and II) hydroxides are bases, non-metal "hydroxides" are acids (especially with high positive charges on the non-metal.) Then we have amphoteric hydroxides like zinc and aluminum that afford zincates and aluminates in very alkaline media. $\ce{Mn(OH)3}$ is a base but $\ce{H... |
If we take **phenolate ion** ($\ce{C6H5O-}$) and **acetate ion** ($\ce{CH3COO-}$) which one would be more stable ?
Although Phenolate ion has more(4) resonating structure compared to acetate ion(2),acetate is more stable because it has two equivalent resonating structure of same energy. My question is why having equ... |
How can we identify bases and acids by their chemical formulas?
Take for example this reaction. I know that HNO3 is an acid and KOH is a base, but if I didn't know that how would I be able to identify that using the chemical formulas
$\ce{HNO3(aq) + KOH(aq) \rightarrow KNO3(aq) + H2O(l)}$ |
I'm studying for exam tomorrow and ran into another question that i'm having trouble with. This one seems easy but I am not getting the right answer.
> How many milliliters of 0.202 M NaOH should be added to 25.0 mL of 0.0233M salicylic acid to adjust the pH to 3.50?
>The answer from the text book is $2.2mL NaO... |
I'm studying for exam tomorrow and ran into another question that i'm having trouble with. This one seems easy but I am not getting the right answer.
> How many milliliters of $0.202$ M NaOH should be added to $25.0$ mL of $0.0233$M salicylic acid to adjust the $pH$ to $3.50$?
>The answer from the text book is ... |
If we take **phenolate ion** ($\ce{C6H5O-}$) and **acetate ion** ($\ce{CH3COO-}$) which one would be more stable ?
Although Phenolate ion has more(4) resonating structure compared to acetate ion(2),acetate is more stable because it has two equivalent resonating structure of same energy. My question is why having equ... |
Why having equivalent resonating structure gives more stability? |
In the reaction E(g) <--> P(g) at 25°C, equilibrium is reached when the pressure of the product is 0.100 that of the reactant. What is ΔG in joules?
Using ΔG = RT ln K, my answer is -8.31 * 298 * ln (1.00) J.
However, the answer is -8.31 * 298 * ln (0.100) J. Wouldn't this mean that ΔG > 0, therefore favoring the r... |
Why isn't ΔG equal to zero for this equilibrium reaction? |
In the reaction $\ce{E(g) <=> P(g)}$ at 25°C, equilibrium is reached when the pressure of the product is 0.100 that of the reactant. What is $\Delta G$ in joules?
Using $\Delta G = \text{RT} ln \text{K}$, my answer is $-8.31 * 298 * ln (1.00) \ \text{J}$.
However, the answer is $-8.31 * 298 * ln (0.100) \ \text{J}$... |
I'm studying for exam tomorrow and ran into another question that i'm having trouble with. This one seems easy but I am not getting the right answer.
> How many milliliters of $0.202$ M NaOH should be added to $25.0$ mL of $0.0233$M salicylic acid to adjust the $pH$ to $3.50$?
>The answer from the text book is ... |
Looks like a classic to me. But since this is homework, <strike>I will not provide a full reaction scheme</strike> and only give some hints.
1. Your starting material is a $\beta$-ketoester (1,3-dicarbonyl compound).
- Where is the most CH-acidic position in this molecule?
- Benzylchloride is an alkylating age... |
Not all the matches have sulfur but only some types in [The Preparatory Manual of Black Powder and Pyrotechnics
by Jared Ledgard](http://books.google.it/books?id=370UwG8CuNwC&pg=PR7&dq=match+composition&hl=it&sa=X&ei=JIM6U5ibNKaR5ASd1oGQAQ&ved=0CDIQ6AEwAA#v=onepage&q=match%20composition&f=false) see page 191, you can ... |
Do redox reactions count? What about a some gas other than carbon dioxide then?
Transition metal halides are reduced by $\ce{CN-}$ and form cyano complexes, while a part of the cyanide is oxidized and released as dicyan:
$\ce{2 CuCl2 + 10 KCN -> 2 K3[Cu(CN)4] + (CN)2 ^ + 4 KCl}$
$\ce{AuCl3 + 4 KCN -> K[Au(... |
I know, by nature, normally atoms are stable. But I wonder, if it is possible to compress an atom, say the Hydrogen atom, to infinite density by applying external force? *After all, electrons and protons would attract each other by electrostatic forces and nuclear forces are also there at least up-to a certain distance... |
Typical filter paper used in chemistry lab (e.g. Whatman #1) exhibits autofluorescence in near UV with excitation maximum at 365 nm and emission maximum at 440 nm. It was reported in literature[1] that fluorophores from filter paper can be extracted by PBS buffer in wide range of pH, and thus they are at least partiall... |
Why is filter paper fluorescent? |
Looks like a classic to me. But since this is homework, <strike>I will not provide a full reaction scheme</strike> and only give some hints.
1. Your starting material is a $\beta$-ketoester (1,3-dicarbonyl compound).
- Where is the most CH-acidic position in this molecule?
- Benzylchloride is an alkylating age... |
You have three *miscible* colored liquids you want to separate quick, cheap, and easy at will? There must be two orthogonal properties.
1) Couple one chromophore to a superparamagnetic particle, e.g., a ferrofluid. It is pulled out in a strong and strongly divergent magnetic field'
2) Couple the second chromopho... |
I'm preforming a liquid liquid extraction on a 1 Liter water sample for GC analysis. The procedure calls for 3 extractions with 50ml of CH2CL2. Would one extraction with 150ml produce different results? |
How is the Nitrate Ion (NO3) formed? |
I understand how the Nitrite(NO2) ion can be formed and have a negative charge, but the Nitrate(NO3) ion is confusing me. I made some simple drawings to try to explain what I don't understand:
http://i.imgur.com/yEKuSKb.png
Does the "electron from outside" that the Oxygen receives, as indicated in the drawing, ... |
(NH4)2C2O4+AgNO3
Is my equation correct? I left out the Spector ions.![enter image description here][1]
[1]: https://i.stack.imgur.com/6SKUn.jpg |
I understand how the Nitrite(NO2) ion can be formed and have a negative charge, but the Nitrate(NO3) ion is confusing me. I made some simple drawings to try to explain what I don't understand:
![enter image description here][1]
Does the "electron from outside" that the Oxygen receives, as indicated in the drawi... |
I'm preforming a liquid liquid extraction on a 1 Liter water sample for GC analysis. The procedure calls for 3 extractions with $50~mL$ of $\ce{CH2CL2}$. Would one extraction with $150~mL$ produce different results? |
I am supposed to write the precipitation reaction for
$\ce{(NH4)2C2O4 + AgNO3 ->[\ce{H2O}]}$
Is my equation correct? I left out the Spector ions.![enter image description here][1]
[1]: https://i.stack.imgur.com/6SKUn.jpg |
Which salt precipitates from a solution of ammonium oxalate and silver nitrate? |
According to WolframAlpha, the change in enthalphy in the combustion of propane is -2220 kJ/mol. How do I calculate the activation energy required start the reaction in the first place? Do you use the same principles as when calculating delta H or am I missing something mind bogglingly obvious?
|
How much activation energy is required to combust propane? |
My book says:
>"As single ions of a metal are not associated in the solid with single ions of a non metal, separate units of ionic compounds do not exist. It is, therefore, wrong to talk of a molecule of an ionic compound".
I know ionic solids exist in form of crystal lattice but why can't we isolate a single mol... |
Why don't molecules of ionic compounds exist? |
If the absorbance of something is 0, what is the equilibrium constant? In a reaction, the absorbance is 0, so the concentration of the product is 0. The concentration of one of the reactants is also 0. What does this say about the equilibrium constant? You would have to divide by 0, suggesting that keq doesnt exist for... |
If absorbance is 0, what is the equilibrium constant? |
Are we talking about uv-vis absorption?
Supposed that you are monitoring the right wavelength and that the extinction coefficients are not ridiculously small, you are outside the limits of experimental error.
If you still do not see any absorption, this means that the species isn't there (anymore).
If it isn't... |
Are we talking about uv-vis absorption?
Supposed that you are monitoring the right wavelength and that the extinction coefficients are not ridiculously small, you are outside the limits of experimental error.
If you still do not see any absorption, this means that the species isn't there (anymore).
If it isn't... |
Are we talking about uv-vis absorption?
Supposed that you are monitoring the right wavelength and that the extinction coefficients are not ridiculously small, you are outside the limits of experimental error.
If you still do not see any absorption, this means that the species isn't there (anymore).
If it isn't... |
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