An electrically neutral entity consisting of more than one atom (n > 1). Rigorously, a molecule, in which n > 1 must correspond to a depression on the potential energy surface that is deep enough to confine at least one vibrational state. This tag should be applied to question about certain ...

learn more… | top users | synonyms

1
vote
1answer
57 views

Can you electrolyse a single H2O molecule?

I don't know why I'm asking or why you'd want to but I'm just curious. Every resource I read about electrolysis says the reaction is $\ce{2H_2O (l) \rightarrow 2H_2 (g) +O_2 (g)}$. Can you ...
-7
votes
1answer
29 views

Molecules and atoms [closed]

Which contains the fewest molecules? Which contains greatest number of atoms? 0.5 g of hydrogen 4.0 g of oxygen 11.0 g of carbon dioxide
3
votes
2answers
281 views

Are there different types of symmetry? [duplicate]

What factor does the symmetry of a molecule play? For example, I know water is asymmetric so does this therefore make water polar (I know in fact that is is)? It may sound ignorant due to my lack of ...
2
votes
1answer
37 views

How many moles of sodium are there in 10mls of 30% sodium chloride?

How many moles of sodium are there in 10mls of 30% sodium chloride? 30% of 10mls is 3g NaCL. There is 3000mg of NaCl and would that be divided by the molecular weight of NaCl or of just Na? I ...
1
vote
0answers
16 views

phase differences between conical intersections and light-induced conical intersections?

I've read recently about light-induced conical intersections, a phenomenon where conical intersections can be artificially introduced to molecules, and that this can be observed even in diatomic ...
2
votes
2answers
58 views

Why are Chiral Molecules such a big deal? [closed]

Today, I came across the discovery of a Chiral Pair in interstellar space. I know that A chiral molecule is a molecule that is not superimposable on its mirror image. But why is it such a big deal? ...
2
votes
1answer
84 views

Do cyclic oxygen molecules exist and their theoretical stability?

Do oxygen molecules ever become cyclic shapes like carbon and other elements? Why doesn't oxygen form cyclic compounds? How stable would they be if they do exist. Especially more than 3 oxygens. ...
0
votes
1answer
35 views

Why Use Lewis Structures to Determine Radicals

As far as I know, Lewis Structures are convenient for representing molecules, but give no insight on the actual electron orbitals. For example: The Lewis Structure of $\ce{O_2}$ does not reflect ...
0
votes
1answer
45 views

A problem on rate of diffusion

At a particular temperature and pressure it takes just 8.256 minutes for a 4.893 liter sample of Neon (Ne) to diffuse through a porous membrane. How long will iodine diffuse in similar conditions? ...
4
votes
0answers
18 views

Steric hindrance of an unbonded electron pair

This question is half inspired by this question, and half inspired by the structure of molecules like hydrazine and hydrogen peroxide. When I was looking at the aforementioned molecules, I started ...
2
votes
1answer
68 views

How does molecular orbital theory explain CH4?

I have understood the formation of $\ce{CH4}$ by valance bond theory, but I'm having trouble understanding it through molecular orbital theory. The energy level diagram of molecular orbitals of $\ce{...
20
votes
1answer
972 views

Why do the atoms in molecular models have the colors they have?

Molecular models are a great tool for visualizing a molecule in three-dimensional space. These models even appear on the web (practically every chemical's Wikipedia page), and there is a very specific ...
0
votes
1answer
40 views

Model of London forces and Hydrogen Bonding; the question is carried on forward, partially, as a personal question, from another question [closed]

Does Model of London forces and Hydrogen Bonding are themselves complicated and require multiple sub-models and assisted theories to explain its correctness. I asked this question in the form (...
3
votes
1answer
56 views

Shape of Allene Molecule

Allene, $\ce{H2C=C=CH2}$, has two $\ce{=CH2}$ groups perpendicular to each other. This is the same as hydrogen peroxide's $\ce{H}$ atoms. Is there any reason why they adopt the perpendicular ...
4
votes
1answer
51 views

Dipole moment of molecule (isolated vs in solution)

Would you expect a dipole moment determined in solution to be different from that in an isolated molecule? If so, why?
2
votes
1answer
38 views

How to quantize the shape of a molecule?

I am looking for numbers which tell you something about the 3D shape of the molecule, and is also easily calculated. One of these is the acentricity factor. I am aware of this one. My problem is you ...
1
vote
1answer
41 views

Colligative properties

I have some problems with these properties. 1) Lowering vapor pressure and boiling point. It happens because the solute molecules take space in the surface of the liquid so a lower number of the ...
2
votes
1answer
50 views

Do absorbances of different compounds at one wavelength sum up?

Question on my practice exam. The answers to the questions were not released, otherwise I could work backwards to figure out how to solve it. As it stands, though, I can only guess the method to solve ...
1
vote
0answers
28 views

why the formula of coca cola can not be find using chemistry? [duplicate]

i mean we have SPECTROSCOPY to stablish what molecules make a compound and also we have advanced chemistry so why is SO HARD to find the formula of coca cola ? simply buy a bottle examine it to ...
18
votes
1answer
140 views

Do symmetric hydrogen bonds in neutral molecules exist?

As far as I know, there have only few truly symmetric hydrogen bonds been observed. Unquestionable is the existence of it in the bifluoride ion, $\ce{[F-H-F]-}$, see also here. There are a couple of ...
-1
votes
1answer
74 views

How to determine the molecular formula of a compound given percentages of the elements?

If the molecular mass of a compound is given as 'm' and it consists of two elements 'A' and 'B'. The compound it composed of x% of 'A' and y% of 'B'. How do I find the molecular formula of the ...
16
votes
1answer
652 views

Why is a S-S bond stronger than an O-O bond?

I'm wondering why exactly the single bond between two sulfur atoms is stronger than that of two oxygen atoms. According to this page, an $\ce{O-O}$ bond has an enthalpy of $142 \rm~\frac{kJ}{mol}$, ...
3
votes
2answers
57 views

What exactly happens when vegetable oil is partially hydrogenated?

My current assumption is that partial hydrogenation requires a polyunsaturated fat, because partial implies at least one but not all, which means there must be at least two double bonds in the fat, ...
8
votes
1answer
219 views

Materials with solid volume greater than liquid volume

Water has a solid volume greater than its liquid volume. This question is in two parts. 1) Are there other materials that have solid volumes greater than liquid volumes? 2) What about the structure ...
0
votes
0answers
25 views

Electrical driving force

The question is kind of related to chemistry. Electrical driving force happens between ions when negative or positive charged ions is concentrated on a side more than the other. The teacher ...
0
votes
0answers
37 views

Strength of London Dispersion Forces - Why do rings have stronger dispersion forces? [duplicate]

My textbook says, Rings can be stacked on top of one another to give rise to stack of closely spaced rings, hence they have overall stronger dispersion forces. Ring > Linear > Branched With similar ...
0
votes
1answer
64 views

How can I search molecules by constituent atoms

Given a set of atoms, I would like to find (some / the most common) molecules that include only (some/all) atoms of the set. Is there any online search engine that can do this? E.g. Atoms={C,H} ...
3
votes
0answers
70 views

How to determine the empirical formula given mass percentages of the elements and the molecular weight?

A compound has $67.3 \% \rm~C,4.62 \%~N,6.93 \%~ H$ and O. Determine the molecular formula of the compound knowing its molar mass is $283\rm~\frac{g}{mol}$. My solution : The percentage for the ...
1
vote
1answer
49 views

Can you create artificial molecules with a machine?

Is it possible to create molecules with machines? For example: you shoot one Oxygen-atom (O) on one diatomic Hydrogen ($\ce{H2}$) to create one water molecule ($\ce{H2O}$).
3
votes
1answer
97 views

Stability of CN molecule

The CN molecule has been observed spectroscopically in comets where pressure has been estimated to be as low as $10^{-10}$ mm Hg. Draw a Lewis structure for CN. Suggest an explanation as to why this ...
4
votes
1answer
69 views

How was the composition of DNA studied before the knowledge of its structure?

In a large polymer molecule (such as a DNA chain) which is made from multiple component monomers containing many atoms, how was it determined that the chain was made up from the four groups of ...
1
vote
1answer
41 views

In which cases do you say “oxide” when naming a molecule?

Based on the names of following molecules I got quite confused about the correct nomenclature: $\ce{NaHCO3}$ $\ce{K2SiO3}$ $\ce{PbCrO4}$ In none of the above molecule names you ever say "oxide" ...
5
votes
3answers
935 views

Is there a way to use free software to convert SMILES strings to structures?

So far I've been unsuccessful in finding an open source tool that will convert a large number (>100k) of SMILES strings to a chemical structure. Is this really only solved by commercial applications? ...
4
votes
1answer
585 views

Why is NO2 formed when N valency is 3

Sorry if the question is silly but this is troubling me more than enough. Here's what I know about chemical formula: Reverse the valencies of the combining elements. But in this case, $\ce{NO2}$ is ...
1
vote
2answers
130 views

Shouldn't all of group 16 form double bonds? [duplicate]

I notice that out of all of group 16 oxygen is the only element that can form a double bond. Why is that because shouldn't all of group 16 be able to form a double bond and be diatomic because they ...
1
vote
1answer
44 views

Can $\ce{CO_2}$ be separated into $\ce{C}$ and $\ce{O_2}$? [duplicate]

I am a grade 8 student and I need to do some background research for a science project of our choice, and my project relies on if $\ce{CO_2}$ can be separated into a $\ce{C}$ and $\ce{O_2}$. So, Is ...
4
votes
1answer
86 views

How is a side-group that contains a double bond named?

In my chemistry lecture, we are working on the naming and nomenclature of organic molecules. When we got to the naming of alkenes and alkynes, we were told that the functional group had to be in the ...
0
votes
1answer
115 views

Are the collisions between the real gas particles perfectly elastic?

Well my question is simple, if two real gas particles are colliding (head on collision) then will the kinetic energy will be conserved i.e. will it be a perfectly elastic collisions?
3
votes
2answers
68 views

Is this graphic of molecules correct?

First off, huge fan of chemistry, not a chemist – do be nice :D Would an image like this make sense as an infographic for the molecular composition of the air? I especially wonder if the different ...
2
votes
1answer
53 views

What would carbon-oxygen polymer be called?

So I have a chain molecule made of carbon and oxygen, and I'm not sure what it would be called. Would any of you lovely fellows be able to help me? The best name I've been able to come up with so ...
1
vote
0answers
47 views

Can one component of a mixture penetrate the skin if the whole mixture cannot?

There's a general rule that says that compounds under 500 dalton are able to penetrate the skin without any special vehicle (such as ethanol). I've started using castor oil, which contains different ...
14
votes
1answer
256 views

Symmetrize nearly symmetric molecule

In the overall good paper of Beruski et. al.,[1] an algorithm of how to symmetrize an "almost symmetric" molecule by symmetrizing the distance matrix is given for the example of Methane. The ...
1
vote
2answers
75 views

Is water a heterogeneous molecule? [closed]

My question is based upon the statement found here: an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium ...
0
votes
1answer
47 views

Which of the following samples is impossible? [closed]

Given the following atomic masses: Aw(Al) = 26.98 amu Aw(O) = 16.00 amu Aw(C) = 12.01 amu Aw(H) = 1.00 amu Aw(Fe) = 55.85 amu I'm trying to determine which of the following doesn't make sense, ...
1
vote
1answer
159 views

Structure diagrams indicate plausible structures? [closed]

Structure diagrams have a hexagonal, "chicken wire" shape, which leads to more elegant representations of some molecules than others. For example, the following diagram must deviate from the usual ...
0
votes
3answers
102 views

Teaching: Two elements that make XY2 and XY4 molecules

I am not a chemist, but I will be explaining chemistry to some third-graders. I want to give the example of how different things can be made of the same parts, but arranged differently. My "real world"...
2
votes
1answer
350 views

Why is Iodine's melting point is lower than water?

My teacher told us that melting point of Iodine is lower than Ice as it is a Simple molecular structure bonded by weak van der waals forces. However I gooogle and found out its melting point is 113.7°...
1
vote
0answers
84 views

positions of a methane molecule with carbon atom at the origin [closed]

Let $\text{CH}_4$ be the molecule of Methane: The four hydrogen atoms form vertices of a regular tetrahedron with the carbon atom in the center of the regular tetrahedron. Here we regard all atoms ...
2
votes
2answers
8k views

What is the difference between “molecular mass”, “average atomic mass” and “molar mass”?

I don't understand the difference between "molecular mass" and "average atomic mass". They seem like the same thing to me. Is it that average atomic mass is just the weighted average of the "weights"/...
0
votes
1answer
205 views

Molarity of Sodium Ion Concentration (and some really weird answers…)

I know how to do this problem really easily but I don't know why my answer is wrong... The problem is: What is the molarity of sodium ions in a solution prepared by diluting $250\ \text{mL}$ of $0....