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Excellent question. On the one hand, the vapor pressure of water (or any other volatile liquid) is a function of the temperature alone, but on the other, if you assume that the mole fraction is constant you find that the vapor pressure of the water changes even though the temperature is constant.
#The short answer#... |
Excellent question. On the one hand, the vapor pressure of water (or any other volatile liquid) is a function of the temperature alone, but on the other, if you assume that the mole fraction is constant you find that the vapor pressure of the water changes even though the temperature is constant.
#The short answer#... |
Excellent question. On the one hand, the vapor pressure of water (or any other volatile liquid) is a function of the temperature alone, but on the other, if you assume that the mole fraction is constant you find that the vapor pressure of the water changes even though the temperature is constant.
#The short answer#... |
Excellent question. On the one hand, the vapor pressure of water (or any other volatile liquid) is a function of the temperature alone, but on the other, if you assume that the mole fraction is constant you find that the vapor pressure of the water changes even though the temperature is constant.
#The short answer#... |
pH scales are just a special case of [solvonium/solvate scales][1], which are *a way to keep track of the concentration of solvonium/solvate ions*. They can be defined for any (usually protic) liquid solvent in macroscopic amounts (the limit of many molecules). Particles don't have pH, and I'm not sure it's possible to... |
I want to remove a layer of 2 mm thick carbon black on a copper bowl. I have tried different solvents, but the carbon seems to be very resistive.
Which formula solves carbon black without solving copper? |
So, I need a method of estimating the influence of a surface (rate constant would do for a start), the idea is to estimate just Reactant + Surface -> Product in a turbulent liquid flow.
Now I am aware of the book "The properties of gases and liquids" by Poling and Prausnitz which gives me two terms for estimating di... |
Independent from my general kinetics question here - http://chemistry.stackexchange.com/questions/5056/estimating-surface-reactions-liquid-turbulent-flow - I am only interested in responses regarding Gaussian in this question.
I would like to know if it is feasible to predict or model the influence of a surface (met... |
Gaussian and Surface Reactions - Doable? |
I want to remove a layer of 2 mm thick carbon black on a copper bowl. I have tried different solvents, but the carbon seems to be very resistive.
Which formula solves carbon black without solving copper? The bowl is made from pure copper. It will melt at roughly 1000 degree Celsius. |
So, I need a method of estimating the influence of a surface (rate constant would do for a start), the idea is to estimate just Reactant + Surface -> Product in a turbulent liquid flow.
Now I am aware of the book "The properties of gases and liquids" by Poling and Prausnitz which gives me two terms for estimating di... |
I just started with Molecular dynamics simulations. My background is computer science but I'm learning about scientific computing and thus my jump into MD.
Having said that, I was asked to calculate the percentage of each conformer in vacuum at a certain temperature of the Methylcyclohexane molecule. Assuming that e... |
I am trying to create the molecule of the methylcyclohexane in the equatorial and axial conformers. I read [in this site](http://research.cm.utexas.edu/nbauld/teach/cyclohex.html) about the chair conformation. My molecule looks like the following picture (created in Molden)
![Methylcyclohexane axial conformer][1]
... |
i always knew that carbon can not be turned to diamond artificially but while watching a video i learned that a diamond can be made from the ashes of a man , how is this possible? sorry if i put the wrong tags |
How to make artificial diamond? |
In a carbonyl or -OH group, it's clear the oxygen acts as a hydrogen bond acceptor.
Do metals act as hydrogen bond acceptors or donors and if so, how can I tell as what it's acting? |
Are metals hydrogen bond acceptors or donors? |
Page 11699 of [this paper](http://pubs.acs.org/doi/abs/10.1021/ja011357l) has one approach to what you want: basically, you compute the relative Gibbs free energies of the possible stable conformers, assume they can interconvert, and use a Boltzmann distribution to work out what the percentages are.
> First, we sele... |
I'd like know if this is right. The reaction between $NaCl$ and $H_2SO_4$ should yield $HCl$ and sodium sulfate. This is a double substitution, true? No oxidation took place here. The thing is, when I tried the reaction in the lab, the resulting solution (gas bubbled into water) seemed to be sulfuric acid. Simply enoug... |
I'd like know if this is right. The reaction between $NaCl$ and $H_2SO_4$ should yield $HCl$ and sodium sulfate. This is a double substitution, true? No oxidation took place here. The thing is, when I tried the reaction in the lab, the resulting solution (gas bubbled into water) seemed to be sulfuric acid. Simply enoug... |
I'd like know if this is right. The reaction between $NaCl$ and $H_2SO_4$ should yield $HCl$ and sodium sulfate. This is a double substitution, true? No oxidation took place here. The thing is, when I tried the reaction in the lab, the resulting solution (gas bubbled into water) seemed to be sulfuric acid. Simply enoug... |
I'd like know if this is right. The reaction between $\ce{NaCl}$ and $\ce{H_2SO_4}$ should yield $\ce{HCl}$ and sodium sulfate. This is a double substitution, true? No oxidation took place here. The thing is, when I tried the reaction in the lab, the resulting solution (gas bubbled into water) seemed to be sulfuric aci... |
Does anyone know what causes things like xanthan gum to make water into a slimy substance on the molecular level? |
How do xanthan gum and other hydrocolloids work? |
You did go to [Gaussian's Documentation on the subject][1], right?
In principle, it should work. In practice, you should consider using massive firepower, and the plane-wave codes (NWChem, abinit, VASP, etc. etc.)
Also, I question whether any of these codes *properly* model bond breaking on a surface, i.e. met... |
In para-aminobenzoic acid, how can I know whether the amino group loses a proton or not when pH exceeds 8.5? I have only found two values for pKa but I never found info about the pKa (in this case it would be the third pKa at pH>8.5) of the amino group.
In any case I guess at basic pH, negative charge over NH2 would... |
As I understand it, the boiling point elevation in a particular solvent (in this case water) is a function of a particular constant of that solvent, and the molality of a dissolved substance. In turn, the maximum molality is a function of the solubility of the compound, as well as the van 't' Hoff factor. Thus it would... |
What is the highest the boiling point of water can be raised? |
why does the graph of ln[A] vs time produce a straight line for the first order rate law?
also why does the graph of time vs 1/B produce a straight line for the second order rate law? |
I'd like to calculate Bond Dissociation Energy and Bond Energy for ATP to a similar molecule. What free (at least for academic use) computer programs which natively support and document BDE?
If you don't mind, could you provide a tutorial for using those programs to perform the calculations? |
I saw ingeniously simple "cooler box" yesterday - a double-walled plastic box with some liquid between the walls. You freeze it, and it keeps temperature near the freezing point of that liquid, until the liquid melts, while you can store dry foods inside.
Now, the efficiency of such a box will depend on volume of th... |
I've always heard that different isotopes of the same element have exactly the same chemical properties. But for example, I've read that an aromatic compound which has the hydrogen atoms interchanged by deuterium becomes odorless.
So, are situations in which neutrons do matter (besides nuclear decays)? |
I think isotopic analogues have mostly of the same bulk physical properties. There are some striking differences, e.g. water and heavy water (D2O) have perceptibly different boiling points. There are many spectroscopies where isotopic substitution has a dramatic effect on the spectrum: including vibrational spectrosc... |
I think isotopic analogues have mostly the same *bulk* physical properties.
- There are some striking differences, e.g. water and heavy water (D2O) have perceptibly different boiling points.
- There are many spectroscopies where isotopic substitution has a dramatic effect on the spectrum: including vibratio... |
If you convert your equation to [mol format][1] or another format supported by [OpenBabel][2] you can use its tools to add 3D structure information to the files. Also if you need quality conformations (and you are part of a university) there are (free) tools like [OpenEye's Omega][3] which can quickly give biologically... |
Can someone explain me whether a protein would bind to carbon?
And why? (what bond?) |
Do proteins bind to carbon? If so how? |
I am using a rotary evaporator to separate DCM (dichloromethane) from some nasty tars.
Before the evaporation is completed, I stop the process and collect the remaining slurry.
The slurry is then positioned in a constant temperature oven, for a secondary evaporation. After cooling in a desiccator, the tar is measured... |
Can someone explain me whether a protein (like an antibody) would bind to carbon? The carbon arises due to electron beam induced deposition of Polyethylglycol (PEG). The carbon molecules that arise are either due to the PEG that dissociates or due to molecules, that are present in the microscope chamber as contaminatio... |
I am using a rotary evaporator to separate DCM (dichloromethane) from some nasty tars.
Before the evaporation is completed, I stop the process and collect the remaining slurry.
The slurry is then positioned in a constant temperature oven, for a secondary evaporation. After cooling in a desiccator, the tar is measured... |
I've seen a couple of companies making flasks *entirely* from PTFE or PFA, which might be suitable. They may not hold up to heating with internal vacuum though, for example, check out the notes [here](http://www.brandtech.com/prodpage.asp?prodid=V107797).
And yes, the typical safety coatings are on the outside to ho... |
Aoyagi et al. (J. Am. Chem. Soc., Vol. 115, No. 24, 1993) reported that the addition of 2-lithio-1,3-dithiane to the alpha-chiral (*S*)-2-Acetylpiperidine gives the (2 *S*,3 *S*)-configured product. It is stated that the diastereoselectivity of this 1,2-addition (*dr* = 6.2) is predicted by Cram's model involving compl... |
Aoyagi et al. (J. Am. Chem. Soc., Vol. 115, No. 24, 1993) reported that the addition of 2-lithio-1,3-dithiane to the alpha-chiral (*S*)-2-Acetylpiperidine gives the (2 *S*,3 *S*)-configured product. It is stated that the diastereoselectivity of this 1,2-addition (*dr* = 6.2) is predicted by Cram's model involving compl... |
Aoyagi et al. ([J. Am. Chem. Soc., Vol. 115, No. 24, p 11393][2]) reported that the addition of 2-lithio-1,3-dithiane to the alpha-chiral (*S*)-2-Acetylpiperidine gives the (2 *S*,3 *S*)-configured product. It is stated that the diastereoselectivity of this 1,2-addition (*dr* = 6.2) is predicted by Cram's model involvi... |
In [an article][1] I am trying to understand the following occurs: (summarized below)
>Synthesis of octahedral $\ce{Cu_2O}$ seeds:In a typical synthesis, 2.9946 g of $\ce{Cu(CH_3COO)_2}$ was dissolved in deionizedwater (20 mL) using a beaker under a constant stirring at 70°C for 2 min. A dark precipitate was produce... |
If you convert your equation to [mol format][1] or another format supported by [OpenBabel][2] you can use its tools to add 3D structure information to the files. Also if you need quality conformations you could use tools [OpenEye's Omega][3] or as I prefer [Balloon][4] which can quickly give biologically significant st... |
I'm reasonably unfamiliar with chemical notation, and recently I've come across something I'm not sure how to interpret. In this article,
http://pubs.acs.org/doi/abs/10.1021/jp036735i
the authors refer to the "surface groups" denoted by $\equiv\text{Ti}-\text{F}$ and $\equiv\text{Ti}-\text{OH}$. Similarly, this... |
What happens when you mix alum with soap? |
Finding transition states in Gaussian – focus: Electrophilic Addition Reaction
First of all, I aim for two things with this post – on the one hand to produce a manual for other people to use, but also to verify what I obtained via searching, asking a more experienced user as well as receiving a reply from Gaussian s... |
Bromotricholoromethane adds to 1 hexane on heating in presence of peroxide .
I think that the reaction should follow anti-markovnikov addition of bromine but answer in my textbook says , it'll happen here according to markovnikov addition. Can the answer be wrong ?
What is the difference here , between peroxide... |
Bromotricholoromethane is added to 1 hexene on heating in presence of peroxide.
I think that the reaction should follow anti-Markovnikov addition of bromine but answer in my textbook says, it'll happen here according to Markovnikov addition. Can the answer be wrong ?
What is the difference here, between peroxid... |
Bromotricholoromethane is added to 1-hexene on heating in presence of peroxide.
I think that the reaction should follow anti-Markovnikov addition of bromine but answer in my textbook says, it'll happen here according to Markovnikov addition. Can the answer be wrong ?
What is the difference here, between peroxid... |
I've learnt in Chemistry that for example in Chromium, the 4s subshell only has one electron in favor of making the 3d subshell half-full. Also, for Copper the same happens.
What other circumstances does this happen under? Do ions obey the same pattern, e.g. Mn+? |
In which cases does the 3d subshell take precedence over the 4s subshell? |
I've got the following from a [supposed new energy-storage technologist][1]. It's supposed to be a fancy new cheap, high-powered, highly scalable battery. I want to know if this is known chemistry, and if there's anything genuinely revolutionary about it:
> "Basic materials in MEG's E-SOURCE™ power cells are lead m... |
Is there anything in the literature that supports revolutionary claims for this "new" sulphuric-acid battery? |
Increased vibration causes the atoms in an object to spread out farther away. Thus, with added heat, and object goes form a solid to a liquid to a gas (and then to plasma, with enough heat). Why is it then, that when a heat something like cake batter, it solidifies? |
Why does heat solidify cake batter? |
##The classical model of electron flow approach##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric potential is analogous to the gravitational energy difference between the top and bottom of the plane in the pinball machine. Now consider ... |
##An approach using a classical model of electron flow##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric (potential) energy difference driving the displacement of the electron is analogous to the gravitational energy difference in the pi... |
##An approach using a classical model of electron flow##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric (potential) energy difference driving the displacement of the electron is analogous to the gravitational energy difference in the pi... |
##An approach using a classical model of electron flow##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric (potential) energy difference driving the displacement of the electron is analogous to the gravitational energy difference in the pi... |
Usually textbooks on CI takes the SCF Hartree-Fock orbitals as a starting point. Can one use the configuration interaction method starting directly from the single-particle Slater determinants avoiding a iterative procedure. This question concerns mainly small molecules like the hydrogen molecule. Do I get a high inacc... |
##An approach using a classical model of electron flow##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric (potential) energy difference driving the displacement of the electron is analogous to the gravitational energy difference in the pi... |
I read this at this webpage: http://www.whfoods.com/genpage.php?dbid=90&tname=nutrient#impactcookingstorageprocessing
> **How do cooking, storage, or processing affect potassium?**
>
> Potassium losses from cooking of high-potassium foods can be
> significant. In the case of spinach for example, potassium levels... |
How can potassium disappear after cooking? |
##An approach using a classical model of electron flow##
You can think of an electron flowing through a medium as analogous to a pinball bouncing around a pinball machine. The electric (potential) energy difference driving the displacement of the electron is analogous to the gravitational energy difference in the pi... |
For example, iron and tin(II) sulfate will react to produce iron(II) sulfate and tin:
$\ce{Fe + SnSO4 -> FeSO4 + Sn}$
With the following half equations:
$\ce{Fe + SO4^{-2} -> FeSO4 + 2e-}$
and
$\ce{Sn^{2+} + 2e- -> Sn}$
but where does the "2" come from? Why can't it be:
$\ce{Fe + SO4^{-5} -> FeSO4 ... |
How is it determined how many electrons are transferred in REDOX reactions? |
In chemistry, we recently did a lab where we observed the different ways of reading pH of several different substances. We used things such as red cabbage juice, litmus paper, pH paper and a pH probe. One of the substances we tested was water. When we used the pH probe, it came back with a reading around 8.0. When we t... |
I need to make a saturated solution of Na2CO3 and according to the available data I should add 22 gm in 100 ml of water at 25 degree celsius.
I wanted to make 300 ml solution,which would require 66 gm. But, even after adding 110 gm of the salt, no turbidity appears which might indicate saturation. So I believe that... |
For example, iron and tin(II) sulfate will react to produce iron(II) sulfate and tin:
$\ce{Fe + SnSO_4 -> FeSO_4 + Sn}$
With the following half equations:
$\ce{Fe + SO_4^{-2} -> FeSO_4 + 2e-}$
and
$\ce{Sn^{2+} + 2e- -> Sn}$
but where does the "2" come from? Why can't it be:
$\ce{Fe + SO_4^{-5} -> F... |
What is the difference between a mixture and a composed substance? |
I would like to know what is the difference between a chemical element and a type of atom? Can anyone give the definition, please! |
What is a chemical element? |
Shouldn't iron oxide be able to form without water? It *is* just iron and oxygen. I don't really understand what the dot followed by the H2O means either. I was reading on wikipedia, but I have a rather terrible understanding of chemistry.
What purpose does water serve in rust formation, and what does it mean for a m... |
Why can't rust form without water? |
I hear abou things like dioxin, but I really don't see what's dangerous about plastics-shouldn't you be ble to just breathe it out, or pass it out of your system? How would it cause cancer? |
Chemically Speaking, What's Bad About Inhaling Plastics? |
I hear about things like dioxin, but I really don't see what's dangerous about plastics-shouldn't you be ble to just breathe it out, or pass it out of your system? How would it cause cancer? |
What do you mean by a pseudohalogen/pseudohalide and how do you tell whether a molecule/ion is a pseudohalogen/pseudohalide ? |
what is a pseudohalogen/pseudohalide? |
To fill with drinkable water, I have lots of empty 19lt carboy bottles. Since they came from different people and companies, I have to check their healthiness to decide wheter they can be sterilise for reuse or not.
I need to detect if a 19lt carboy bottle was used previously for gas, lpg, diesel etc. or is there an... |
The primary dangers from plastics themselves come when the polymer, and any compound put in to make the chemical matrix flexible, separate from the polymer matrix. There are several such compounds which are known to be problematic to human biochemistry:
* **Phthalates** - These are aromatic diesters, with a structur... |
For example, iron and tin(II) sulfate will react to produce iron(II) sulfate and tin:
$\ce{Fe + SnSO4 -> FeSO4 + Sn}$
With the following half equations:
$\ce{Fe + SO4^{2-} -> FeSO4 + 2e-}$
and
$\ce{Sn^{2+} + 2e- -> Sn}$
but where does the "2" come from? Why can't it be:
$\ce{Fe + SO4^{5-} -> FeSO4 ... |
I need to make a saturated solution of $\ce{Na2CO3}$ and according to the available data I should add $22\ \text{gm}$ in $100\ \text{ml}$ of water at $25^\circ\text{C}$.
I wanted to make $300\ \text{ml}$ solution,which would require $66\ \text{gm}$. But, even after adding $110\ \text{gm}$ of the salt, no turbidity ... |
I understand(I think) the mass and density aspect, i.e. the more protons you have, the more the element weighs, also the denser the atom is. What about everything else(color, for example)? Elements are not just masses and densities. |
How do the differences in the number of protons result in such great differences in elemental properties? |
everyone!
I am not in school, and this is not a "homework" assignment ;-) I just have a rather silly question that I'm sure has an 'easy' answer that has so far eluded me.
I'm attempting to write a small program that will calculate the values for the Ideal Gas Law, specifically for molecular Hydrogen (H2) in s... |
It's not the protons, it's the *electrons*. Electrons are the main determinant of chemical bonding, and it is the bonding of differing atoms that creates the huge variety of chemical properties.
For example, the color of molecules often is driven by the *transition elements*, starting at atomic number 21. These me... |
If a reaction requires a "strong" acid - what does this mean? Does it mean any acid of a specific concentration or pH? Are only certain acids classed as "strong"? I have read on wikipedia that it needs to ionise completely in an aqueous solution - in this case, is a strong acid (for example, HCl) still classed as a str... |
What is a "Strong" Acid? |
How would I grow my own and build functional solar cells? I've read and researched that they're mostly a crystal structure of something like silicon. I would assume I'd be able to grow my own crystals and sandwich this in a process of some sort with a `p-type` and `n-type`, etc. |
Create my own solar cells? |
Right, how do you systematically name them? Also, do you number them from the double bond end or the Carboxyl end?
Ie would it be something like. 2-methyl Hept-3-enoic acid?
Scuse the bad question and I made up the example, sorry! I'm really confused!
Thanks!! |
PLEASE HELP!! AlkEnoic acids problems? Thanks! |
Egg white consists of mostly Ovalbumin. It is a protein, and so will be hard to distinguish from other proteins in a baked product. Egg white changes structure to a solid polymer on cooking. You could dissolve it in a mixture of detergent and hair perm, returning the Ovalbumin to its uncooked state, and then run it thr... |
PLEASE HELP!! AlkEnoic acids problems? Thanks! Ie unsaturated fatty acids |
To add to Nick's great answer, I believe you are confusing $K_c$, the equilibrium constant, with $Q_c$, the reaction quotient.
The reaction quotient is defined as the ratio of the product of the concentrations of the products to the product of the concentrations of the reactants, under any conditions or relative amo... |
Nomenclature of alkenoic acids - which group has priority: the alkene or the acid? |
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