Questions tagged [molecules]

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 molecules or a class of them.

Filter by
Sorted by
Tagged with
-2
votes
2answers
70 views

Can somebody help me understand this sentence?

"The molar enthalpy of vaporisation of a liquid is the enthalpy change when one mole of the liquid changes into one mole of its gas at the boiling temperature." The part which i am not sure of is the ...
0
votes
1answer
57 views

Is there a way to find the mixture type with just the molecular formulas and masses of the solute and solvent?

If you had the molecular formula and molar mass of a solvent and a solute and no other specific information about the two, could one deduce the type of mixture (suspension, colloid, solution) they ...
3
votes
2answers
335 views

Enantiomer or not?

My professor said that this compound is an enantiomer but I think it has a plane of symmetry and has no chiral carbons. Am I missing something ?
6
votes
3answers
2k views

How was the diatomic nature of many common gaseous elements originally determined?

How did scientists find out that $\ce{Cl2, H2, O2}$ atoms have a two-atomic molecular structure ?
7
votes
3answers
5k views

Reason for vibration of molecules

Why do molecules of a body exhibit vibrational motion? Is it due to interaction between various molecules of the body, or interatomic interactions between atoms in the same molecule? If it is because ...
2
votes
1answer
560 views

Stability of CN molecule

The $\ce{CN}$ molecule has been observed spectroscopically in comets where pressure has been estimated to be as low as $10^{-10}\ \mathrm{mmHg}$. Draw a Lewis structure for $\ce{CN}$. Suggest an ...
1
vote
0answers
132 views

Bombarding molecules with electrons

I have been reading a book titled "High Voltage Engineering". It seems to me that in this book it is considered that in a gas when they collide an electron with a molecule, the molecule is stationary ...
49
votes
2answers
18k views

Why is an 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 $142~\mathrm{kJ~mol^{-1}}$, ...
0
votes
1answer
2k views

In the carbonate anion, which atoms gain the two electrons?

In the carbonate ion ($\ce{CO3^2-}$), is it the oxygen or the carbon that has gained the two additional electrons?
7
votes
2answers
10k views

What are the fumes that form above liquid nitrogen?

What is the composition of liquid nitrogen fumes? Is direct contact with these fumes harmful?
0
votes
1answer
574 views

Why does mixing inks make subractive colors?

I have little knowledge of color theory and chemistery. Recently I came to know that printers use CMYK colored inks and combine them in different proportions to achieve any color on print. Let us ...
5
votes
1answer
755 views

All resonance structures of the hydrogen molecule

This answer written by Jan says that "a professor of mine claimed to have drawn some 18 (or was it 80?) different resonance Lewis structures." Please reproduce those resonance structures of the ...
3
votes
1answer
475 views

How does a diatomic molecule vibrate in response to heat?

Do you know of any applet/animation that shows how a diatomic molecule like $\ce{O2}$ or $\ce{N2}$ vibrate in response to/ to produce heat? Can it vibrate only on one axis, the one joining the two ...
2
votes
1answer
838 views

Definition of relative atomic mass

I found out there are two definitions of relative atomic mass $A_\mathrm r$. First definition is $A_\mathrm r$ is the mass of 1 atom of an element relative to 1/12 the mass of carbon-12 atom. It can ...
11
votes
4answers
17k views

Why do people still use the mole (unit) in chemistry?

I know that the mole is widely used in chemistry instead of units of mass or volume as a convenient way to express amounts of reactants or of products of chemical reactions. I'm wondering why people ...
2
votes
0answers
86 views

Are the $+\leftrightarrow+$ and $-\leftrightarrow-$ methanol rotational transitions dipole-allowed?

I am quite confused about the origin and justification of the rotational selection rules of methanol, and I would appreciate any help or references. As far as I understand, there are three irreducible ...
4
votes
2answers
4k views

When does hydrogen bonding happen?

What kinds of molecules will experience hydrogen bonding (inter and intra)? Why does it occur for some H atoms but not others?
0
votes
1answer
345 views

Largest molecule that isn't polymer? [closed]

What is the largest molecule (synthetic or natural) that isn't a polymer -- let's say, bigger than 3000 dalton?
8
votes
2answers
3k views

Is there any scenario in which the size of a molecule increases due to an increase in temperature?

Take an ice cube for example. Heat is applied in a closed container until it is vaporized completely. Will the molecule's size be larger (on average)? Is there a substance that you know of that has ...
0
votes
1answer
494 views

clock reaction dilutions for KI

Stock solution 0.1M KI solution 100mL Volume of KI 30 10.5 5.25 Volume of water 0 19.5 14.75 concentration of KI 0.1 0.05 0.025 How did they calculate these ...
5
votes
3answers
2k views

What does 'organic/non-organic molecule' means exactly? [duplicate]

I am new to the organic chemistry world. I was delving for the exact answer to my question, and I've found some results: In wikipedia (french), is was mentioned that an organic molecule contains ...
3
votes
1answer
74 views

Are there any other (meta)stable oxygen molecules beyond O3?

Apart from Ozone, are there any longer oxygen molecules that are at least stable for short amounts of time? What configurations would that be?
2
votes
1answer
3k 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
1answer
351 views

Nuclear spin isomerism in molecules other than H2

I was reading my teacher's material about ortho- and para- hydrogen, and I found stated that "every homonuclear molecule, with nuclides with spin other than zero ($\ce{H2}$, $\ce{D2}$, $\ce{T2}$, $...
1
vote
1answer
240 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 ...
5
votes
1answer
225 views

Reaction of Silicon monoxide with alcohols

Elements from the carbon group tend to form compounds with two oxygen's. Let's say I want to produce $\ce{SiO_2}$ out of $\ce{SiO}$ by mixing it with some alcohol, for example: $$\ce{SiO + CH_3-CHOH-...
-11
votes
1answer
160 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
785 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
2k 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
48 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 ...
0
votes
3answers
17k views

Identifying the number of bonding and lone pairs without a dot and cross diagram

I've just learned how to predict the shapes of molecules in class today using VSEPR theory. I would like to ask is there anyway to find the number of bond pairs and lone pairs without drawing a dot-...
3
votes
1answer
1k 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. Why ...
8
votes
1answer
36k views

What holds atoms together? [duplicate]

I know atoms are held together by Ionic and Covalent bonds and i understand the ionically bonded atoms are held together by electrostatic forces. What about covalent bonds? How are molecules of bonded ...
-1
votes
2answers
15k views

Is neon a molecular element?

Does the chemical element neon consist of a molecule? For example, oxygen consist of two atoms together. But is that the same with neon?
0
votes
1answer
165 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 ...
2
votes
1answer
1k views

How does molecular orbital theory explain CH4? [closed]

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{...
0
votes
1answer
76 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
476 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?
7
votes
2answers
1k views

Really how rare are hydrogen atoms?

Hasok Chang, a chemist, but perhaps more a philosopher recently published the book Is Water H2O? . Chang used the question and an extensive web of arguments ultimately as a platform to support a ...
2
votes
1answer
54 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
86 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 ...
10
votes
3answers
659 views

Explain the formation of replicators to a layman

I am reading The Selfish Gene by Richard Dawkins. I am on chapter two. He speaks of the observation of the formation of amino-acids when you simulate environmental conditions of primordial earth. ...
1
vote
0answers
45 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 ...
3
votes
2answers
1k 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, ...
10
votes
1answer
908 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
1answer
311 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
1answer
202 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
97 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" ...
1
vote
2answers
1k 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 ...
19
votes
1answer
690 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 2 3 4 5 7