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One example of this is HCL and KOH. Why would the acid not just give the Hydrogen ion in HCL to form CL- AND KOH2+? |
Why are acids characterized by giving Hydrogen and Bases characterized by receiving it when acid and base reactions are double displacement reactions? |
I have asked my teacher, as she was introducing the concept of mole to us, why *that* number was chosen, instead of more convenient one. She told me that it came from the definition of the mole, that is the number of atoms in 12g of Carbon 12. When I asked why that definition was chosen, she answered me that my questio... |
Why is the definition of the mole as it is? |
>Why is the definition of the moles as it is?
It is a rather arbitary definition that the mole is the number of atoms in 12g of carbon 12. This has not always been the definition. For example, prior to 1960, the definition was based upon oxygen rather than carbon-12.
The first standard was based upon 1 gram of... |
>Why is the definition of the moles as it is?
It is a rather arbitary definition that the mole is the number of atoms in 12g of carbon 12. This has not always been the definition. For example, prior to 1960, the definition was based upon oxygen rather than carbon-12.
The first standard was based upon 1 gram of... |
>Why is the definition of the moles as it is?
It is a rather arbitary definition that the mole is the number of atoms in 12g of carbon 12. This has not always been the definition. For example, prior to 1960, the definition was based upon oxygen rather than carbon-12.
The first standard was based upon 1 gram of... |
I have asked my teacher, as she was introducing the concept of mole to us, why *that* number was chosen, instead of more convenient one. She told me that it came from the definition of the mole, that is the number of atoms in 12g of Carbon 12. When I asked why that definition was chosen, she answered me that my questio... |
One example of this is HCL and KOH. Why would the acid not just give the Hydrogen ion in $HCl$ to form $Cl^-$ AND $KOH_2^+$? |
>Why is weight of 1 mole of substance equal to atomic/molecular mass in grams?
>According to me, it happens because mole has been defined in such a way.
Yes! That is correct.
>It is defined as the numbers of particles in 12 g of C12. If it were 24 g, instead of 12 g, then the weight of 1 mole of substance wou... |
The bond enthalpy associated with a O=O double bond is equal to 495kJ/mol. Does that mean that adding enough kinetic energy in the form of heat will eventually cause the bonds to break and create monoatomic oxygen? |
Will heating diatomic oxygen enough break the O=O bonds? |
I was taught to balance redox equations with acid/base considerations. Instead of arbitrarily adding $\ce{H^+}$ and $\ce{HO^-}$ ions and memorizing separate rules for acidic and basic solutions, I was taught simply to keep these three things in mind:
1) Charge must be conserved.
2) Mass is similarly conserved.
... |
What is the $\ce{K_{a}}$ value for $\ce{H^+}$. I understand that the hydrogen proton doesn't stick around in solution by itself for very long. Nonetheless, does it have a $\ce{K_{a}}$ value? Can it have a $\ce{K_{a}}$? I think it _can_ have one but quantifying it might be hard. Its $\ce{K_{a}}$ value I think would c... |
What's the Acid Ionization Constant of the Hydrogen Proton? |
What software does the PDB use to generate these "cel-shaded" protein models with outlines around foreground atoms?
[![Leptin][1]][2]
(Leptin: [May 2012 Molecule of the Month][3] by David Goodsell)
[1]: https://i.stack.imgur.com/hwdmMl.jpg
[2]: http://www.rcsb.org/pdb/education_discussion/molecule_of_th... |
About two weeks ago I put some ordinary unleaded petrol into a plastic water bottle, as a temporary measure (long story, don't ask!). It has now formed a reddish liquid at the bottom of the bottle.
The bottle was emptied prior to adding the petrol, but probably still contained a small amount of water when the fuel w... |
>1) How come I've never seen my professor's method mentioned anywhere? I've Googled, looked at scholarly papers; looked in advanced analytical textbooks, etc.
It is entirely possible that no one has published that approach! It is certainly not common in introductory chemistry textbooks.
>2) How were you taught?
... |
I was taught to balance redox equations with acid/base considerations. Instead of arbitrarily adding $\ce{H^+}$ and $\ce{HO^-}$ ions and memorizing separate rules for acidic and basic solutions, I was taught simply to keep these four things in mind:
1) Charge must be conserved.
2) Mass is similarly conserved.
... |
Where could we find a good description of graph theory applied to the general problem of isomer enumeration and chemical graph theory? |
#Why is the definition of the moles as it is?
Here what say [The International System of Units (SI)](http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf)
> “Atomic weights” were originally referred to the atomic weight of
> oxygen, by general agreement taken as 16. But whereas physicists
> separated the i... |
>With no knowledge of chemistry, is it realistic to undertake a biochemistry class?
I would say that taking a biochemistry course without *any* background in chemistry or biology would be very **difficult**, but it would be **possible**.
>The course description lists the following prerequisites: "Basic knowledge ... |
I can't tell you for sure what *is* happening, but I can tell you what *could be* happening.
#Physical Adsorption#
It is possible that the proteins are not *chemically* adsorbed, but rather *physically* adsorbed. The article you cited implies that this is the case.
Many proteins in the presence of nano-scale hyd... |
I am trying to prepare some iron(III) naphthenate.
And the raw materials are : ferric(III) choloride, and naphthenate acid, toluene, deionized water;
Everything worked well in lab scale: final iron(III) napthenate dark red in color and soluable in toluene was obtained easily;
however, I encountered problem... |
What is the possible side reactions when preparing iron(III) naphthenate? |
I am trying to prepare some iron(III) naphthenate.
And the raw materials are : ferric(III) chloride, and naphthenate acid, toluene, deionized water
Everything worked well in lab scale: final iron(III) naphthenate dark red in color and soluble in toluene was obtained easily;
However, I encountered problem whe... |
What are the possible side reactions when preparing iron(III) naphthenate? |
I am trying to prepare some iron(III) naphthenate.
And the raw materials are : ferric(III) chloride, and naphthenate acid, NaOH, toluene, deionized water
Everything worked well in lab scale: final iron(III) naphthenate dark red in color and soluble in toluene was obtained easily;
However, I encountered prob... |
>Why is weight of 1 mole of substance equal to atomic/molecular mass in grams?
>According to me, it happens because mole has been defined in such a way.
Yes! That is correct.
>It is defined as the numbers of particles in 12 g of C12. If it were 24 g, instead of 12 g, then the weight of 1 mole of substance wou... |
>Why is the definition of the moles as it is?
It is a rather arbitary definition that the mole is the number of atoms in 12g of carbon 12. This has not always been the definition. For example, prior to 1960, the definition was based upon oxygen rather than carbon-12.
The first standard was based upon 1 gram of... |
Imagine you randomly spread in a cubic space of volume $m^3$ (or in a sphere of volume $V_s$, as you prefer), $n_A$ particles $A$ and $n_B$ particles $B$. Particles $A$ are spheres of volume $V_A$ and are not moving. Particles $B$ have no volume (they are points) and are moving linearly (reflecting at the boundaries of... |
The other answers explain things in terms of the activation energy barrier, but they don't explain **why** the activation energy barrier is lowest for K. I will attempt to do that here.
When a metal reacts with water, several things must happen (not necessarily in this order):
1. One or more electrons have to be ... |
Is it preferable to balance redox equations with $\ce{H^+}$ or $\ce{H_3^+O}$? I think the latter, because first, the bare hydrogen proton doesn't exist in water solution. So why write down something we know not to exist?
I ask because in this problem, if we balance using both species, $\ce{H^+}$ and $\ce{H_3^+O}$,... |
Is it preferable to balance redox equations with $\ce{H^+}$ or $\ce{H_3^+O}$? I think the latter, because first, the bare hydrogen proton doesn't exist in water solution. So why write down something we know not to exist?
I ask because in this problem, if we balance using both species, $\ce{H^+}$ and $\ce{H_3^+O}$,... |
Is it preferable to balance redox equations with $\ce{H^+}$ or $\ce{H_3^+O}$? I think the latter, because first, the bare hydrogen proton doesn't exist in water solution. So why write down something we know not to exist?
I ask because in this problem, if we balance using both species, $\ce{H^+}$ and $\ce{H_3^+O}$,... |
How come the oxygens *transferred* in redox reactions are always the superoxide anion?
For example, I have this set of rules, and the rules are implicitly referring to the $\ce{O^{2-}}$ anion, a potent base (otherwise the rules wouldn't make sense; for example, it makes sense that a base in acidic solution is prot... |
Superoxide Anion in Redox - Origin? |
How come the oxygens *transferred* in redox reactions are always the superoxide anion?
For example, I have this set of rules, and the rules are implicitly referring to the $\ce{O^{2-}}$ anion, a potent base (otherwise the rules wouldn't make sense; for example, it makes sense that a base in acidic solution is prot... |
How come the oxygens *transferred* in redox reactions are always the $\ce{O^{2-}}$anion?
For example, I have this set of rules, and the rules are implicitly referring to the $\ce{O^{2-}}$ anion, a potent base (otherwise the rules wouldn't make sense; for example, it makes sense that a base in acidic solution is pr... |
$\ce{O^{2-}}$ Anion in Redox - Origin? |
How can a phase that appears at high temperature be thermodynamically stable at room temperature? For example, $\alpha$-alumina is a phase that is formed at temperatures above $1000^\circ C$. How is the same phase stable at room temperature? |
How can a phase be thermodynamically stable at room temperature if it only appears at high temperature? |
A leak in the air conditioning system of an office building releases 12k of $CHF_2Cl$ per month. If the leak continues, how many kilograms of $Cl$ will be emitted into the atmosphere each year?
My working out is as follows:
$$
12kg = CHF_2Cl \\
\text{Cl Mass in compound} = \frac{35.45}{86.448}*100 = \text{41%}... |
I have a question about the refrigerant's pressure in the inlet of an evaporator. Why should the sat-temp of the refrigerant be below the required temp of the cooled compartment ? Shouldn't the refrigerant's temp at the exit of the evaporator be equal to that of the cooled compartment ?
Thanks all. |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
Sulfate is a separate ion.
... |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
Sulfate is a separate ion.
... |
the chemistry of fog machines? |
This is the question from the text book: <br>
![enter image description here][1]
[1]: https://i.stack.imgur.com/v4gQ7.png
This is what I did, since it worked with all the previous questions (similar to this).
$$
\frac{\frac{4}{3}\pi(7*10^8)^3*1.4}{1.008} * 6.022*10^{23}
$$
This equals $1.2 *10^{51}$,... |
I believe the molecule CH3CH2CH2Cl to be saturated, since there are only single bonds between the carbon atoms, but my workbook says it's unsaturated. Why? |
Is CH3CH2CH2Cl saturated or unsaturated? |
I am asked to find the enthalpy change of formation of the following:
$$\ce{N2 + 1/2O2 -> N2O}$$
I am given the following enthalpies of reaction:
$$1:\:\ce{C + N2O -> CO + N2} \:\:\:\Delta H_f =-193$$
$$2:\:\ce{C + 1/2O2-> CO} \:\:\Delta H_f=-111$$
How do I calculate enthalpy change of formation of the nitrous... |
I understand that all polyurethane (PU) materials off gas VOCs. I tried finding the % composition of the gases off-gassed by PU, but I am not able to get satisfactory answer. On the same note, why are these gases off-gassed?
Thanks! |
What is the chemical composition of VOC's off-gassed from polyurethane? |
(you've probably done this by now, but...)
Apply some common sense to the quantity you are working with. Are you making this on an industrial scale, or one small item to use in your lab? If the latter, don't worry about it. Unless something massively toxic is expected to come out (VX, for example) just don't go out ... |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
The nitrogen atom, as opposed... |
aluminum mercury alloy is used as a chemical reagent to reduce compounds, such as the reduction of imines to amines,in this case mercury destroy aluminium oxide layer which protect aluminium to react with water.
alloy of aluminium and gallium which similar to above alloy make the aluminium more reactive by preventin... |
What is the structure of RCH=NH? |
I know that $\ce{NaHCO3}$ is sodium bicarbonate, but According to [Wikipidia](http://en.wikipedia.org/wiki/Carbonate):
> In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, $\ce{CO3}$.
$\ce{NaHCO3}$ also has the $\ce{CO3}$ group, but is it a carbonate?
That... |
Is $\ce{NaHCO3}$ a carbonate? |
Aluminum mercury alloy is used as a chemical reagent to reduce compounds, such as the reduction of imines to amines,in this case mercury destroy aluminium oxide layer which protect aluminium to react with water.
Alloy of aluminium and gallium which similar to above alloy make the aluminium more reactive by preventin... |
What is difference between aluminium mercury alloy and gallium aluminium alloy? |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
The nitrogen atom, as opposed... |
What is the Structure of FeSO₄ • NO? |
I know that $\ce{NaHCO3}$ is sodium bicarbonate, but According to [Wikipedia](http://en.wikipedia.org/wiki/Carbonate):
> In chemistry, a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, $\ce{CO3^{2-}}$.
$\ce{NaHCO3}$ also has the $\ce{CO3^{2-}}$ group, but is it a carbonat... |
Is NaHCO₃ a carbonate? |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_{eq}$ for a reaction with unequal numbers of... |
Should binding constants be unitless when deriving fractional occupancy equations from reactions? |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_{eq}$ for a reaction with unequal numbers of... |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_{eq}$ for a reaction with unequal numbers of... |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_{eq}$ for a reaction with unequal numbers of... |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_{eq}$ for a reaction with unequal numbers of... |
I would consider it a carbonate. Chemistry of sodium bicarbonate, or sodium hydrogen carbonate, or simply baking soda, is very similar to that of just sodium carbonate, or $\ce{Na_2CO_3}$.
Adding a strong acid to either $\ce{Na_2CO_3}$ or $\ce{NaHCO_3}$ will effect bubbling. Why? The acid protonates the carbonate o... |
I know that $\ce{RCH=NH}$ is an imine.
What is it's structure? |
Is it possible to crystallize vegetable glycerin?
I saw a myth about it online and was wondering if it is possible. |
Sounds like you need a food-grade surfactant. Maybe you could try [lecithin][1]?
The problem is that cocoa powder is mostly made of stuff that is not soluble in water (hydrophobic). So, to create the emulsion, you will need to "package" the powder molecules in something they are soluble in. You could either use a su... |
Acet* indicates Ethyl, but does not offer two Carbon atoms, but three.
Acetaldehyde is Ethanal, Acetic acid is Ethanoic acid, but Aceton is Propanon (yes, I'm aware that there is no Ethanon).
Why is Acetone called Acetone? |
Why is it ACETone? |
Honestly, I don't see how anyone could have predicted this outcome before seeing the actual $\ce{pK_a}$ data. If you look up the acidities of methanal and ethanal, you find $\ce{pK_a}$ = 13.27 and 13.57 respectively. A pretty small difference to begin with. As the picture below illustrates, in the case of methanal we... |
It is known that binding (aka association) constants are in fact unitless, as has been discussed [here][1] already. However, I'm not a chemist and am confused about when one should or should not use units when working with association constants. [One source][2] says:
> $K_\text{eq}$ for a reaction with unequal numbe... |
I was looking up some ion channel blockers. What does (+) or (-) below mean?
[(+)-Bicuculline][1]
[(-)-Bicuculline methiodide][2]
[1]: http://www.tocris.com/dispprod.php?ItemId=2028#.U4t67vnoTy6
[2]: http://www.tocris.com/dispprod.php?ItemId=159237#.U4t6cfnoTy4 |
(+)-Bicuculline, what does (+) mean? |
Honestly, I don't see how anyone could have predicted this outcome before seeing the actual $\ce{pK_a}$ data. If you look up the acidities of methanal and ethanal, you find $\ce{pK_a}$ = 13.27 and 13.57 respectively. A pretty small difference to begin with. As the picture below illustrates, in the case of methanal we... |
Using these equations:
(Fe2): Fe + CuSO4 --> FeSO4 + Cu
(Fe3): 2Fe + 3CuSO4 --> Fe2(SO4)3 + 3Cu
Beginning with 0.78g of iron, the theoretical yields of copper are 0.89g (with Fe2+) and 1.33g (with Fe3+), and the actual yield was 0.78g of copper. I know to find of the ratio of the moles of iron used to the moles ... |
Which ion of iron is produced in a reaction between iron and copper(II) sulfate? |
Honestly, I don't see how anyone could have predicted this outcome before seeing the actual $\ce{pK_a}$ data. If you look up the acidities of methanal and ethanal, you find $\ce{pK_a}$ = 13.27 and 13.57 respectively. A pretty small difference to begin with. As the picture below illustrates, in the case of methanal we... |
I tried drawing out (R)-1,1,2-trimethylcyclohexane but I can't seem to figure it out. I think I"m getting hung on assigning priorities.
I've labeled the chiral carbon with an asterisk. I've also drawn out all the groups it is attached to. I gave the hydrogen the lowest priority (4) and I'm giving the methyl carbon ... |
I am trying to dissolve copper(I) iodide and copper(I) thiocyanate in ammonia. I am quite sure that they both dissolve in liquid ammonia, and are insoluble in ethanol.
If I were to purchase a 2.0M solution of ammonia in ethanol, like the one [here](http://www.sigmaaldrich.com/catalog/search?interface=All&term=ammon... |
Honestly, I don't see how anyone could have predicted this outcome before seeing the actual $\ce{pK_a}$ data. If you look up the acidities of methanal and ethanal, you find $\ce{pK_a}$ = 13.27 and 13.57 respectively. A pretty small difference to begin with. As the picture below illustrates, in the case of methanal we... |
Using these equations:
\begin{aligned}
\text{(Fe2):}&&\ce{ Fe + CuSO4 &-> FeSO4 + Cu}\\
\text{(Fe3):}&&\ce{ 2Fe + 3CuSO4 &-> Fe2(SO4)3 + 3Cu}
\end{aligned}
Beginning with $0.78\:\mathrm{g}$ of iron, the theoretical yields of copper are $0.89\:\mathrm{g}$ (with $\ce{Fe^{2+}}$) and $1.33\:\mathrm{g}$ (with $\ce{Fe... |
The question is about emergence and reductionism.
Except a few exceptions such as dark matter, most phenomenon in nature could be reproduced from the standard model and general relativity up to a great accuracy. Up to a Planck scale, there is no inconsistency between general relativity and quantum theory by means o... |
Is there any emerged master principle in chemistry, like the theory of evolution in biology? |
I'm doing some research on heat pipes [(check here for wiki)][1]. One of the things I'm planning to do is try some different fluids in the pipes. Water (commonly used) has a freezing point that's too high, so I'm looking into fluids that don't freeze up in winter and disrupt the equilibrium in the pipe.
I've randoml... |
Here's a [link][1] to the first page of a book entitled, "The History of Acetone, 1600-1850" by Mel Gorman. The author points out that acetone was known in the Middle Ages and was frequently produced by heating dry lead acetate. I suspect that the "acetate" (or whatever the Latin, French or German term was) root stuc... |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
The nitrogen atom, as opposed... |
>What is the structure of $\ce{FeSO4 \cdot NO}$ that is formed when $\ce{NO}$ is passed through ferrous sulphate solution?
The structure is octahedral.
The Fe ion is at the center of the octahedron.
Five water molecules and the NO molecule occupy the vertices of the octahedron.
The nitrogen atom, as opposed... |
I don't understand why this molecule is assigned S instead of R.
![enter image description here][1]
The H is assigned a priority of 4; the methyl group on the chiral carbon gets 3; the left carbon gets 1 and the right carbon gets 2. The rotation should therefore be clockwise.
I guess what I have an issue w... |
I don't understand why this molecule is assigned S instead of R.
![enter image description here][1]
The H is assigned a priority of 4; the methyl group on the chiral carbon gets 3; the left carbon gets 1 and the right carbon gets 2. The rotation should therefore be clockwise.
I guess what I have an issue w... |
I don't understand why this molecule is assigned S instead of R.
![enter image description here][1]
The H is assigned a priority of 4; the methyl group on the chiral carbon gets 3; the left carbon gets 1 and the right carbon gets 2. The rotation should therefore be clockwise.
I guess what I have an issue w... |
I don't understand why this molecule is assigned S instead of R.
![enter image description here][1]
The H is assigned a priority of 4; the methyl group on the chiral carbon gets 3; the left carbon gets 1 and the right carbon gets 2. The rotation should therefore be clockwise.
I guess what I have an issue w... |
How does Lewis acidity correlate with bactericidal activity? I read on Wikipedia that the two are positively correlated but no explanation was given.
Does it have to do with the movement of electrons - i.e. a current? I'm guessing that having a current passed through you isn't good for you. |
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