A molecule is an electrically neutral group of two or more atoms held together by covalent chemical bonds
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History of Chemistry: Molecules
We know that the Greeks were the first scientists (or better, philosophers) to introduce the idea that matter is made up of little “chunks”, and they named these chunks “atoms”. This idea that matter ...
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Do halogens bond more commonly with each other or themselves?
To me it seems like diatomic elements like $\ce{F2}$, $\ce{Cl2}$, etc. occur more prevalently than diatomic molecules with both, like $\ce{ClF}$.
Is this the case, and if so, what causes diatomic ...
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Prediction of surface atoms in molecule from its graph
If we are given a molecular graph i.e. al the atoms involved and their connectivity, how can we make reasonable prediction if the atom would lie in the surface or in the inner part. On way might be ...
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Electron density definition of single, double, triple bonds?
I was reading this question and the answer by @EricBrown to it and this got me thinking about covalent chemical bonds.
The way I was always taught is that a single bond contains 2 paired electrons, ...
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Empirical formula when given percentages?
A binary compound, of lead and oxygen contains 90.66% Pb, what is the empirical formula for the compound?
How do i use to percentage to get to the regular formula, then how do I change the normal ...
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Partial pressures
How do I find partial pressures if I am only given their percentages? where do I begin?
eg.
O=21% , N=78% , Ar=1% by volume how would I calcluate the partial pressures if total pressure is 1atm.
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Approximation of electron density of a small molecule
Starting point for Quantum Theory of Atoms in Molecules (AIM) is the electron density $\rho(r)$. It could be determined experimentally (X-ray diffractions). I want to know how can we estimate them ab ...
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Polar group strong dipole effect molecular axis
There are some fundamental charactaristics of liquid crystal. One of them is that all liquid crystals are organic compounds and at one side of their long molecular foundation there exists a polar ...
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How different are molecule with same connectivity
Let us represent molecules by graphs (atoms are vertices and bonds are edges).
Let $A$ be the adjacency matrix of the molecular graph. $A_{ij} = b$ where $b$ is either binary: 0 when atom i and j are ...
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How to get the valencies of elements?
How to find the valencies of elements by using it's distribution of electrons?
Explain the method in simple words?
Do you have to study the valencies or is there is a simple way of remembering?
PS: ...
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Number of bonds in a Lewis Structure [duplicate]
I'm asked to find the Lewis Structure of sulfuric acid, $SO_4H^-$. After struggling for a while, I sumply looked it up.
How can this be? Sulfur has 6 electrons in its valence shell, so it should ...
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If magnesium oxide is $\ce{2Mg + O_2 → MgO}$ then why is aluminium sulphate $\ce{2Al^{3+} +3SO_4^{2-} → Al_2(SO_4)_3}$?
Why is it not $\ce{Al_2SO_{12}}$?
Why doesn't the 4 and 3 get multiplied?
Show step by step working of formation of both $\ce{MgO}$ and $\ce{Al_2(SO_4)_3}$.
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How does the reaction Mg + O2 → MgO occur?
$\ce{Mg + O2 → MgO}$
Magnesium, oxygen and magnesium oxide form the above equation.
How?
What do I need to learn to do this? atomic numbers/ valencies?
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Molecular orbital theory & predicting the stability of a molecule?
A question in my chemistry textbook gives me a list of formulas for molecules and ions and then asks me to determine (using molecular orbital theory) whether or not each would exist in a relatively ...
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1answer
54 views
How long can polyethylene molecules be?
In this video, Steve Spangler says the substance he is using (a polyethylene oxide): http://www.youtube.com/watch?v=m-88M75_PCI
He mentions that one molecule would go to the moon and back twice! I ...
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Tool that generates electrostatic maps of molecules?
Do you know any tools that generate electrostatic potential 2d maps of the molecules as an image?
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How to calculate weight of $\ce{CO_2}$ in one kg of fuel
I'm trying to do homework and I have the answers to the problems but I can't read the explanation because it's illegible and I can't find how it's done in my notes.
Here's the simplest example:
...
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Why do single elements in a molecule have an oxidation state of zero?
For example, take $O_2$.
The oxidation state of oxygen is -2, yet once its in a molecule its oxidation state becomes zero?
How is this so?
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How can one find products when one knows the reagents?
I'm going to use an example (I could have used a different one);
On the document it is about the study of the chemical balance of an acid-basic solution.
The chemists have written the chemical ...
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Differences between HHO and H2O
I'm not an expert. In simple words how do they differ HHO and H2O molecules?
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Law of Multiple Proportions: What is the significance of small whole numbers?
I'm new to Chemistry and in my textbook, it describes the Law of Definite Proportions and then goes on to describe the Law of Multiple Proportions.
The example they give is carbon monoxide and carbon ...
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Can magnesium chloride absorb water and ammonia at the same time?
Anhydrous magnesium chloride will absorb ammonia to the tune of ($\ce{Mg(NH3)6Cl2}$).
Incidentally, magnesium chloride is usually a hexahydrate ($\ce{MgCl2(H2O)6}$) at STP.
My question is, could ...
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O2 in a 3- oxidation state?
Has diatomic oxygen ever been observed with a 3- charge, i.e. $O_2^{3-}$? Have any ab intio calculations been done on this ion?
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Why do single, double and triple bonds repel each other equal amounts?
I'm here to share with you something that totally confuses me, as I can't see the logic behind it, and my teacher doesn't know either.
Let's take a set of bonds that's trigonal pyramidal, with a lone ...
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1answer
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Find empirical formula when individual masses are known
I'd like to illustrate my question with an example:
Imagine nickel reacts with fluoride and you start with 0.766 g of nickel, an unknown amount of fluoride and you end with 1.261 g of nickelfluoride. ...
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Shape of C₂H₂ molecule
What is the shape of the $C_2H_2$ molecule?
The fact that is has a triple covalent bond between the 2 carbon atoms and 2 other bonding pairs between the hydrogen and carbon atoms leads me to believe ...
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Why not “Oxygate” OO4(2-)?
So many atoms can be surrounded by oxygen atoms to make anions - chromate, phosphate, etc. In particular there's Tellurate TeO4(2-), Selenate SeO4(2-) and Sulfate SO4(2-) - why not go one step more ...
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What makes a molecule a polyatomic ion?
I checked the Wikipedia page, but it did not seem to provide a very intuitive explanation.
What distinguishes a molecule such that it behaves like a polyatomic ion? I understand that it is a ...
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Why is H₂O a dipole?
Water ($\ce{H2O}$) is a dipole. The reason why is simply because it is not symmetrical, and there are more electrons on the oxygen side than on the hydrogen side.. (Also because of the ...
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What's the relation between amu , mole and grams? [closed]
1 mole of carbon = 6.023 * 10^23 carbon atoms = 12g
...how? how did we get the weight in grams? and what's this weight for? the substance or 1 mole of carbon atoms?
and what's the relation between ...
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Do noble gasses besides Helium form diatomic molecules at low temperatures?
I know that at extremely low temperatures (mK and lower), Helium can form diatomic molecules. Do the other noble gasses also form molecules at extremely low temperatures?
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What is the difference between physical and chemical bonds?
If you characterize the chemical bonds to two categories physical and chemical bonds, how do you do it? Aren't all bonds chemical and physical?
From the freedictionary.com, chemical bond:
Any of ...
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Why do different substances have different boiling points?
For example, why does for example oxygen turn into gas at a much lower temperature than water?
Does it have anything to do with the molecular structure? A water molecule does have a more complex ...
