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Is there a kind of metal that melts very quickly with very low heat or temperature and at the same time becomes hard very quickly?
I'm very naive in chemistry with limited knowledge. So I hope your answers don't have difficult terms :) |
A metal that melts quickly? |
**What is ionic mass?**
The ionic mass is the real mass of the ion that takes in account the weight of the electrons in the overall weight however electrons are much more lighter (0.548 mDa) then the nuclei so in fact usually in spectroscopy is used the mass number, A:
> Total number of heavy particles (protons a... |
Is there a way to control the shape of metal? Suppose I have a fast melting metal, is there a way to make it take a specific shape? Of course I don't mean to like put it in a template to take the shape of a template, but rather to control the shape using a computer or something. Is something like this possible or done?... |
Molten or solid at the end? It can be shaped in an induction field (liquid) or dimagnetically levitated (liquid to solid). Magnetoforming, hydroforming. Spin molten into into an oblate ellipsoid (solid).
http://www.capturedlightning.com/frames/shrinkergallery.html <BR>
Z-pinch and such.
Munroe effect for jet... |
http://www.sigmaaldrich.com/catalog/product/aldrich/495425?lang=en®ion=US <BR>
Gallium-indium eutectic, mp 15.7 C <BR>
http://en.wikipedia.org/wiki/Galinstan <BR>
Galinstan, mp -19 C <BR>
http://www.indium.com/thermal-interface-materials/other/liquid-metal/ <BR>
Menu, 7.6 C to 30 C. <BR>
http://en.wikipedia... |
Given the Ksp for ZnS is 2.5 E-22 and the Ksp for FeS is 3.7 E-19, why would Fe2+ ions remain in the solution but not Zn 2+ with the acidification of the solution?
I have little understanding of this, so I don't have a great attempt at the solution. Thanks! |
I understand that ate complexes can result from the addition of carbanions to neutral aluminum alkyls.
I was wondering what the balanced equation for this reaction is/what the structure would be in solid state - like does it dimerize
2 LiCH2CH3 + Al2(CH2CH3)6 -> ? |
I'm trying to do some quantum chemical calculations for the linear molecule FeP$_2$ in the gas phase as well as its crystal ([orthorhombic symmetry like here][1]). I am lead to believe that in both cases iron has an oxidation state of +6, and phosphorous has an oxidatio nstate of -3. My questions are:
* are such oxi... |
It has 5 valence electrons, but only loses 3 of them to make a +3 ion. Why does this occur?
I believe it may have something to do with how losing 3 electrons leaves you with the p sublevel full, but I do not understand why Bismuth is okay with that. |
Why does Bismuth only create a +3 ion instead of a +5 ion? |
I understand that ate complexes can result from the addition of carbanions to neutral aluminum alkyls.
I was wondering what the balanced equation for this reaction is/what the structure would be in solid state - like does it dimerize
$$\ce{2 LiCH2CH3 + Al2(CH2CH3)6 ->\ \ \ ?}$$ |
Isn't it just that +5 is a lot of (positive) charge for a single cation? Which other (transition) metals do form a $\ce{M^{5+}}$ cation? Just out of my mind, I can't think of any.
Typically, these high oxidation states exist in the form of oxo-anions ($\ce{CrO4-}$, $\ce{MnO4-}$, $\ce{VO4^{3-}}$, etc.) and bismuth is... |
Isn't it just that +5 is a lot of (positive) charge for a single cation? Which other (transition) metals do form a $\ce{M^{5+}}$ cation? Just out of my mind, I can't think of any.
Typically, these high oxidation states exist in the form of oxo-anions ($\ce{CrO4-}$, $\ce{MnO4-}$, $\ce{VO4^{3-}}$, etc.) and bismuth is... |
Given the $K_{sp}(\ce{ZnS})= 2.5\cdot10^{-22}$ and the $K_{sp}(\ce{FeS})= 3.7\cdot10^{-19}$, why would $\ce{Fe^{2+}}$ ions remain in the solution but not $\ce{Zn^{2+}}$ with the acidification of the solution?
I have little understanding of this, so I don't have a great attempt at the solution. |
There are no differences simply the second notation is not recommended by [IUPAC](http://goldbook.iupac.org/M03752.html). The explanation is below:
**What is ionic mass?** The ionic mass is the real mass of the ion that takes in account the weight of the electrons in the overall weight. However electrons are much m... |
Why is the fulfilled electronic configuration of only $p$ orbital is stable. I mean why $II-B $ group with fulfilled $d$ orbital,$II-A$ group with fulfilled $s$ orbital...are not stable. Why makes $p$ orbital so special? |
imagine a manometer in a place which air pressure is 0.8 atm and the gs pressure is more.
we move it to sea level which the aire pressure is 1 atm.
how the gas pressure changes?(the temperature is constant) |
I want to learn basic chemistry, so which textbook do you think I should pick? It should be something both concise and clear. Thank you. |
There are no differences simply the second notation is not recommended by [IUPAC](http://goldbook.iupac.org/M03752.html). The explanation is below:
**What is ionic mass?** The ionic mass is the real mass of the ion that takes in account the weight of the electrons in the overall weight. However electrons are much m... |
In your opinion, what would be the simplest way to balance any size of chemical equation ?
For example here is an equation :
C<sub>12</sub>H<sub>26</sub> + O<sub>2</sub> => CO<sub>2</sub> + H<sub>2</sub>O
I saw some ways by putting letters in front of each molecule but I just don't get too much how to do t... |
![enter image description here][1]
[1]: https://i.stack.imgur.com/xGCJJ.jpg
Question: A solution having composition $p$ (left side of graph) is cooled to just above the eutectic temperature (point $s$ is at $ .18 \; x_{Si} $ and the corresponding tie line intersects the liquidus curve at $ .31 \; x_{Si} $); c... |
Imagine a manometer where air pressure is 0.8 atm and the gs pressure is more.
We move it to sea level which the air pressure is 1 atm.
How the gas pressure changes? (the temperature is constant) |
Delta H for the reaction below is -126 KJ
2Na2O2(s) + 2 H2O(l) ------>4 NaOH(s) + O2 (g)
what is the amount of heat released by the reaction of 25.0 gram of Na2O2 with water? |
Delta H of reaction and finding delta h of components? |
I've been having a conceptual struggle with these two states for a while now, and I'd like to get it cleared up.
A compound AB dissolves in water.
AB(s) + H2O <-> A+(aq) + B-(aq) + H2O(l)
Now, we know that in the case of salts, there can be strong and weak electrolytes based on the degree of dissociation. For... |
Here is an example of the process I just used:
C$_{12}$H$_{26}$ + O$_2$ $\rightarrow$ CO$_2$ + H$_2$O
1.) Start with carbon (completely arbitrary choice). Put 12 on r.h.s.
C$_{12}$H$_{26}$ + O$_2$ $\rightarrow$ 12CO$_2$ + H$_2$O
2.) Carbons are balanced but oxygens are not. Therefore, move on to O. Since... |
Oxidationsnumbers for ester? |
For MALDI or ESI mass spectrometry of large macromolecules (e.g. in the $\approx 100$ kDa to $\approx 10 - 100$ MDa mass range), I've always how measurement error scales with particle mass. Not having any hands on experience with mass spetrometry, and calling anything build in the last 5 - 10 years "modern", are there... |
For MALDI or ESI mass spectrometry of large macromolecules (e.g. in the $\approx 100$ kDa to $\approx 10 - 100$ MDa mass range), I've always how measurement error scales with particle mass. Not having any hands on experience with mass spetrometry, and calling anything build in the last 5 - 10 years "modern", are there... |
I'm doing this homework and I got: 109.5,109.5,109.5 for D. But it says it is wrong. I don't know why. Can someone help me? Everything else I got right
![enter image description here][1]
[1]: https://i.stack.imgur.com/hINIj.jpg |
Here is an example of the process I just used:
C$_{12}$H$_{26}$ + O$_2$ $\rightarrow$ CO$_2$ + H$_2$O
1.) Start with carbon (completely arbitrary choice). Put 12 on r.h.s.
C$_{12}$H$_{26}$ + O$_2$ $\rightarrow$ 12CO$_2$ + H$_2$O
2.) Carbons are balanced but oxygens are not. Therefore, move on to O. Since... |
I am doing a senior project that synthesizes PbS quantum dots and our particles keep crashing out of solution. I was wondering if anyone can give me some advice or information on stabilizing the colloidal solution. The solvent is DI water. I am interested in the chemistry behind stabilization. like what needs to be add... |
I am in high school and haven't had a formal chemistry course, however I am fascinated with biology and picked up a biology book more advanced than the one the school is using to read on my own. The book is http://www.amazon.com/Biology-Peter-Raven/dp/0073227390/ref=pd_sim_sbs_b_1?ie=UTF8&refRID=03D89VN8PMQNE2GQ3DF7 an... |
Is it necessary that the valency of an element must have the same valency ?
For eg. If 2 elements A and B combine with the same mass of C , is it necessary that they have the same valency as they will have when combining AB ? |
In your opinion, what would be the simplest way to balance any size of chemical equation?
For example here is an equation: $$\ce{C12H26 + O2 -> CO2 + H2O}$$
I saw some ways by putting letters in front of each molecule, but I just don't get too much how to do this with this method! My teacher is always speaking... |
I'm making some graphs and I have to label the axes. I want to be extra careful and put the units in even though the meaning of pH is well known. But I have a problem (though a simple one)- pH is a minus logarithm (base 10) of concentration of hydrogen ions (or rather their activity). What is the unit then, is it $[-lo... |
What is the unit of pH? |
Lets say we want the activity coefficient of Cu2+ ions in solution. Would we simply setup one half cell of a Cu electrode in a known concentration of CuSO4 and then connect this to a Standard Hydrogen Electrode.
Using the standard electrode potential of the reaction Cu2+ + 2e- ---> Cu and the Nernst equation coul... |
Lets say we want the activity coefficient of $\ce{Cu^{2+}}$ ions in solution. Would we simply setup one half cell of a $\ce{Cu}$ electrode in a known concentration of $\ce{CuSO4}$ and then connect this to a Standard Hydrogen Electrode.
Using the standard electrode potential of the reaction $\ce{Cu^{2+} + 2e- -> Cu... |
I've been having a conceptual struggle with these two states for a while now, and I'd like to get it cleared up.
A compound AB dissolves in water.
$$\ce{AB(s) + H2O <-> A+(aq) + B-(aq) + H2O(l)}$$
Now, we know that in the case of salts, there can be strong and weak electrolytes based on the degree of dissocia... |
$\Delta H$ for the reaction below is -126 KJ
$$\ce{2Na2O2(s) + 2 H2O(l) ->4 NaOH(s) + O2 (g)}$$
What is the amount of heat released by the reaction of 25.0 gram of $\ce{Na2O2}$ with water? |
Dimension of the equilibrium contant: contradiction of Bridgman's theorem? |
Loosely put, enthalpy is the change in heat of a given reaction. We see input of two moles of sodium peroxide to give a mole of oxygen in the balanced equation. (What are the reduced and oxidized species?) You have a mass of sodium peroixde input, you know how many moles that is, and you know the one equivalent of r... |
angle 6 involves an $\ce{sp^2}$ betweenthe hybridized carbon. In such cases the angle is ~ 120 degrees. Just to elaborate a bit more, if you have four objects arranged in space about a central carbon atom (the sp3 hybridization case), the four bonds from carbon are going to arrange themselves spatially so that the el... |
Loosely put, enthalpy is the change in heat of a given reaction. We see input of two moles of sodium peroxide to give a mole of oxygen in the balanced equation. (What are the reduced and oxidized species?) You have a mass of sodium peroxide input, you know how many moles that is, and you know the one equivalent of r... |
Angle 6 involves an $\ce{sp^2}$ hybridized carbon in the $\ce{C=O}$ double bond. In such cases $\ce{R-C-O}$ angle is ~ 120 degrees. Just to elaborate a bit more, if you have four objects arranged in space about a central carbon atom (the $\ce{sp^3}$ hybridization case), the four bonds from carbon are going to arrange... |
Angle 6 involves an $\ce{sp^2}$ hybridized carbon in the $\ce{C=O}$ double bond. In such cases the $\ce{R-C-O}$ angle is ~ 120 degrees. Just to elaborate a bit more, if you have four objects arranged in space about a central carbon atom (the $\ce{sp^3}$ hybridization case), the four bonds from carbon are going to arr... |
I'm making some graphs and I have to label the axes. I want to be extra careful and put the units in even though the meaning of $\text{pH}$ is well known. But I have a problem (though a simple one): $\text{pH}$ is a minus logarithm (base 10) of concentration of hydrogen ions (or rather their activity). What is the unit... |
The process of ironing of clothes removes (to a large extend) the wrinkles that where introduced in the clothes while drying. Obviously this has to be some physico-chemical process that is initiated/sustained by the heat of the iron and (perhaps) the pressure applied with the iron.
My question is: what is the actual... |
Dimension of the equilibrium constant: contradiction of Bridgman's theorem? |
What are the physico-chemical processes at play in ironing of clothes? |
According to my book, metals want to "lose" electrons to achieve noble gas configuration. But at the same time, copper ions in a galvanic element are going to gain electrons from a zink electrode. Why is it so? Is it because one of them HAS to gain/lose electrons, and zink wins out in terms of achieving noble gas confi... |
If metals want to "lose" electrons, then why will copper ions take electrons from a zink electrode? |
According to my book, metals want to "lose" electrons to achieve noble gas configuration. But at the same time, copper ions in a galvanic element are going to gain electrons from a zinc electrode. Why is it so? Is it because one of them HAS to gain/lose electrons, and zinc wins out in terms of achieving noble gas confi... |
If metals want to "lose" electrons, then why will copper ions take electrons from a zinc electrode? |
I'm having trouble in understanding how to identify chemical compounds as stereoisomers.
In the question below, **D** is the correct answer according to the markscheme. I've drawn out the chemical structure but am unable to see what possible stereoisomers it can form.
I also tried visualising the possible isomers... |
Which compound can exist as stereoisomers? |
http://osf1.gmu.edu/~bbishop1/CHEM%20814-579%20Stereochemistry%20Lecture%20slides.pdf <BR>
Everything you ever wanted to know about stereoisomerism.
Quick answer: Any reasonably tetrahedral atom bearing four different groups (including isotopic substitution and unbonded orbitals) is a chiral center. However, pai... |
I just wanted to check my understanding of this. Given the reaction,
$$ (1) \; \ce{A->B} $$
the corresponding rate law is $ v=k[A] $
Also consider
$$ (2) \; \ce{A <=> B} $$
with forward rate law: $ v_1=k_1[A] $ and reverse: $ v_2=k_2[B] $. This makes the corresponding rate equation $ v=v_1-v_2=k_1[A]-k_... |
I just wanted to check my understanding of this. Given the reaction,
$$ (1) \; \ce{A->B} $$
the corresponding rate law is $ v=k[A] $
Also consider
$$ (2) \; \ce{A <=> B} $$
with forward rate law: $ v_1=k_1[A] $ and reverse: $ v_2=k_2[B] $. This makes the corresponding rate equation $ v=v_1-v_2=k_1[A]-k_... |
http://osf1.gmu.edu/~bbishop1/CHEM%20814-579%20Stereochemistry%20Lecture%20slides.pdf <BR>
Everything you ever wanted to know about stereoisomerism.
Quick answer: Any reasonably tetrahedral atom bearing four different groups (including isotopic substitution and unbonded orbitals) is a chiral center. However, pai... |
Not all reactions can or should be represented with a double arrow. The general-audience example is that you "can't unbake a cake". You are right that there are instances that we assume that k2 is negligible (relative to k1) and therefore a reaction is treated as if it is reversible.
Here's a sample plot of how th... |
I've been having a conceptual struggle with these two states for a while now, and I'd like to get it cleared up.
A compound AB dissolves in water.
$$\ce{AB(s) + H2O <-> A+(aq) + B- (aq) + H2O(l)}$$
Now, we know that in the case of salts, there can be strong and weak electrolytes based on the degree of dissoci... |
Up to my knowledge the reaction mechanism of CaO and $H_{2}O$ is not well understood yet, however seems that for low density CaO, $H_{2}O$ is absorbed over the CaO. The mechanism should be something like this:
$$\ce{CaO + 2H2O -> CaO\cdot2H2O ->Ca(OH)_2 }$$
Your reaction is wrong. [Reference here](http://books.g... |
This is a bit of a weird question but here we go.
You know how when you carry out a reaction with many compounds, when drawing the reactions you just draw a line at a right angle to the bond with a 'R' at the end (see image)?
![R][1]
Then you can specify what group R is in a table (eg: OMe). However, if instead... |
The bonds are: (I have given pictures of what I mean in case there's any ambiguity that I leave open in these questions. Also so that if you want to number the R groups you've got a head-start)
* **Primary amides**, I suspect I might know the answer, extensive.
![enter image description here][1]
* **Secondary... |
How much hydrolysis will likely occur of the following bonds at pH 1-4 in the time period of 1-3 hours? |
The bonds are: (I have given pictures of what I mean in case there's any ambiguity that I leave open in these questions. Also so that if you want to number the R groups you've got a head-start)
* **Primary amides**, I suspect I might know the answer, extensive.
![Primary amides][1]
* **Secondary amides**. Thi... |
The bonds are: (I have given pictures of what I mean in case there's any ambiguity that I leave open in these questions. Also so that if you want to number the R groups you've got a head-start)
* **Secondary amides**, I suspect I might know the answer, extensive. Example is the one in **folic acid**.
![Secondary ... |
Could not a simple way of rationalising this result be to use the formula for a classical Coulombic attraction between point charges?
Given the radial distribution as shown, and the scaling of electrostatic force with r² rather than r, any time spent closer to the nucleus is vastly more important than time spent fur... |
How much heat (in J) is required to produce 2.0L of N2(g) at 77.36 K and 1.0 atm? |
Double layer theories like that of Gouy-Chapman give the electrostatic potential $\ \phi\ $ in solution. For a symmetrical electrolyte and small potential drops $\ \phi\left(x=0\right)-\phi\left(x\rightarrow\infty\right)=\phi_0-0\ \text V=\phi_0$, the theory gives
$$
\phi=\phi_0\exp\left(-\kappa x\right)
$$
where $... |
What is the relationship between migration and the potential of double layer theory? |
How much heat (in J) is required to produce 2.0L of $N_2(g)$ at 77.36 K and 1.0 atm? |
Is it necessary that the valency of an element must have the same valency?
For eg. If 2 elements A and B combine with the same mass of C, is it necessary that they will have the same valency as they would have when combining AB? |
Why are there two possible bond angles for the nitrous acid molecule?
After perusing Wikipedia I found that there are both cis and trans forms of the nitrous acid molecule. I also note that the cis form is sterically hindered. Could this be a reason for the two different bond angles - there are two different geomet... |
Given the molar heat capacity of a partition function as a function of temperature, how would one determine the partition function?
Say the molar heat capacity = $\alpha T^2$ |
Is the end of a cigarette on fire when it is lit? Or is it smoldering? Is there a chemical difference between the two? |
Is the end of a cigarette on fire when lit? |
All these materials are hazardous by skin contact and inhalation. The are toxic and evil. One possibility is soaking overnight in auto supply store generic carburetor cleaner. Another is overnight soak in automatic transmission fluid. Gloves, goggles, disposable activated charcoal painter's mask. If you get anythi... |
You know how when you carry out a reaction with many compounds, when drawing the reactions you just draw a line at a right angle to the bond with a 'R' at the end (see image)?
![R][1]
Then you can specify what group R is in a table (eg: $\ce{OMe}$). However, if instead of adding a substituent to a benzene ring, y... |
`4Fe + 3O2 -> 2Fe2O3(s) + 1625kJ`
This should be endothermic because the energy is in the product. However, if the equation is viewed from the perspective of the reactant, it is endothermic.
Is this endo or exothermic? |
Is this endo or exothermic? |
What is the final temperature of water and iron if a 30g piece of iron at 144°C was dropped into a calorimeter with 40g of water at 20°C?
Specific heat of water is 4.184J/g°C
Specific heat of iron is 0.449J/g°C
-------------------------------------
Here is my work:
Q = mcΔT
Q1 = -Q2
Q1 = (30)(.44... |
Is there a article, book, some account of the discovery that crude oil came from decayed biological material? |
$$\ce{4Fe + 3O2 -> 2Fe2O3(s) + 1625kJ}$$
This should be endothermic because the energy is in the product. However, if the equation is viewed from the perspective of the reactant, it is endothermic.
Is this endo- or exothermic? |
Imagine two companies X and Y. Both companies use very similar technical equipment to carry out a biotechnological process where a chemical reaction is catalyzed by an enzyme. Company X uses an enzyme with a reaction barrier of, say, 15 kcal/mol, while company Y uses a slightly different enzyme to catalyze the same rea... |
Can energy savings be estimated from activation energy differences? |
What is the final temperature of water and iron if a $30g$ piece of iron at $144°C$ was dropped into a calorimeter with $40g$ of water at $20°C$?
Specific heat of water is $4.184J/g°C$
Specific heat of iron is $0.449J/g°C$
-------------------------------------
Here is my work:
$Q = mcΔT$
$Q_1 = -Q_2... |
The situation is not clear.
If your carbon is pure ( why would it be?) then burning down with flame would be the easiest and cleanest solution. Practically nothing solves pure carbon, except melt iron.
If your carbon is not pure, but e.g. you burned some food on the surface, cooking with sodium-carbonate generall... |
What is the final temperature of water and iron if a $30g$ piece of iron at $144°C$ was dropped into a calorimeter with $40g$ of water at $20°C$?
Specific heat of water is $4.184J/g°C$
Specific heat of iron is $0.449J/g°C$
-------------------------------------
Here is my work:
$Q = mcΔT$
$Q_1 = -Q_2... |
Can anyone explain why the melting and boiling points of the noble gases increase as you go down the periodic table? |
Why do the melting and boiling points of the noble gases increase when the atomic number increases? |
I want to remove a layer of 2 mm thick carbon black on a copper bowl on the outside from hanging over wood and coal fire.
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... |
Can anyone explain why the melting and boiling points of the noble gases increase as you go down the periodic table?
Edit: What causes the melting and boiling points to rise when the atomic number increases? What role do the valence electrons play in this? |
The melting and boiling points of noble gases are very low in comparison to those of other substances of comparable atomic and molecular masses. This indicates that only weak van der Waal's forces or weak London dispersion forces are present between the atoms of the noble gases in the liquid or the solid state.
... |
The melting and boiling points of noble gases are very low in comparison to those of other substances of comparable atomic and molecular masses. This indicates that only weak van der Waal's forces or weak London dispersion forces are present between the atoms of the noble gases in the liquid or the solid state.
... |
Mix HCL and NaOH together(reactants are at the same temp) in a calorimeter. Temperature increases, and the book said it's an exothermic reaction. I don't get it. The thermometer is in the solution which means it measures the temp of the solution. It's the system. The temp of a system increases means heat flows in, how ... |
Rearranging the Eyring equation leads to the following:
$$ ∆^\ddagger S^\circ = R \ln{\frac{k \times h}{{k_B}{T}}}+\frac{∆^\ddagger H^\circ}{T} $$
where k is the rate constant, h is the Planck constant, R is the universal gas constant, $ k_b $ is the Boltzmann constant, T is temperature, H is enthalpy, and S is... |
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