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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.

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3
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1answer
84 views

Finding $c$ with Dulong-Petit law on non-molecular substance

The Wikipedia article states the Dulong-Petit law as follows: $$c=\frac{3R}M$$ $c$ is specific heat capacity $[\mathrm{\frac J{kg\; K}}]$ and $R$ the gas constant. $M$ is the molar mass in [g/mole], ...
17
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1answer
3k views

Why do methane molecules have 15 degrees of freedom?

I've just been learning a little thermal chemistry including the equipartition theorem. As part of this, my textbook discusses how to figure out the degrees of freedom for different chemicals. The ...
15
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1answer
848 views

Are there molecules that take the shape of every platonic solid?

Methane is the simplest molecule I know of that takes the shape of a platonic solid — in this case, the tetrahedron. Wikipedia has a page on platonic hydrocarbons that includes molecules with ...
5
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1answer
471 views

How many isotopologues of water are there?

If ordinary water molecules can contain any of the three hydrogen isotopes, $\ce{^1H}$, $\ce{^2H}$, $\ce{^3H}$, and any of the three oxygen isotopes, $\ce{^{16}O}$, $\ce{^{17}O}$, $\ce{^{18}O}$, how ...
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1answer
123 views

What is the most complex molecule we can manufacture without the help of proteins? (soft queston) [closed]

What is the most complex molecule we can manufacture without the help of proteins? This isn't motivated by anything but curiosity about the state of chemical engineering. I realize “complexity” is a ...
3
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3answers
7k views

Determining the structure of N2O using hybridization

I have learnt how to determine the structure of molecules where only the central atom is hybridised like $\ce{ClF3}$, $\ce{C2H2}$, $\ce{PCl5}$, but in $\ce{N2O}$ it seems as though both nitrogen and ...
10
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3answers
433 views

How does a molecule search work by drawing in visual editor?

There are a lot of chemical search engines (such as ChemSpider's Structure search) that allow users to draw and search for a molecule. How does it work? Is the comparison of images used? Could you ...
3
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1answer
3k views

Valence Bond theory, VSEPR theory and predicting the shapes of the molecules

I read about the above mentioned theories then used them to predict the molecular geometry. However, I found that the shape/geometry of a molecule obtained from both the theories was same. For example,...
6
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1answer
482 views

Space filling model for nitrogen molecule

I want to make space filling model for nitrogen molecule. I've learned that van der Waals diameter is to be taken for atom radius. Since van der Waals radius for nitrogen is $\pu{155 pm}$ and bond ...
1
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1answer
326 views

Whats between molecules? [duplicate]

Okay, this will be tricky to explain. But, this is a question that i have been wondering about in quite a long time, okay lets get started, Molecules moves faster in higher temperatures and there will ...
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1answer
3k views

How to calculate average volume of a molecule? [closed]

The molecular weight of glucose-1-phosphate is $\pu{260 g/mol}$ and its density is $\pu{1.5 g/mL}$. What is the average volume occupied by 1 molecule of this compound?
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0answers
346 views

Measure the complexity of a molecule

Back in April, there was an article in new scientist discussing the work of Lee Cronin, who postulated that molecules of a certain complexity must be biological. Cronin has developed a way to ...
3
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1answer
365 views

Substances comprised of large molecules are liquids at room temperature?

I am looking for compounds that are liquid at normal temperatures and are physically very large, to be used in an ellipsometer adsorption experiment. I am currently working with decane. The candidates ...
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0answers
104 views

Why does increasing electronegativity difference result in decreasing density?

I've been collecting data and there's a very strong inverse relationship between electronegativity difference and density ($\pu{R^2}$ value of roughly 0.95 from my data). Is there any chemistry that ...
2
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1answer
46 views

How to add a color to vapors?

I want to add a color to vapors, like the vapor that comes out of glycerine when heated. Is there a chemical compound I can put into glycerine that makes the vapor colorful? Or is there a chemical ...
2
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1answer
7k views

Is SO3 an ion or a molecule?

Earlier I thought that $\ce{SO3^{2-}}$ (sulfite) is an ion with -2 charge but today I read on internet $\ce{SO3}$ (sulfur trioxide) is a molecule with no charge. How can this be possible? Please ...
3
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1answer
4k views

Lone pairs in MO theory?

I have learned that non-bonding MOs are lone pairs. However when considering the MO diagram for the $O_2$ molecule, I do not see any non bonding orbitals yet there are two lone pairs on each oxygen ...
3
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1answer
5k views

What is “mineral spirits”?

I'm working in a project, and for a specific thing, I need to work on a possible recovery of $\ce{HCl}$ in aqueous phase. I found a patent on the net in which they use an amine to make a complex with $...
4
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1answer
65 views

What does the first $1$ mean in $\ce{Li}_2 1 ^1\Sigma_g^+: (1s\sigma_g)^2(1s \sigma_u)^2(2s \sigma_g)^2$?

I am trying to learn the nomenclature behind molecular states and in (Demtröder, 2010) I came across this expression: $$\ce{Li}_2 \color{red}{1} ^1\Sigma_g^+: (1s\sigma_g)^2(1s \sigma_u)^2(2s \...
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1answer
14k views

How to determine relative polarity (basic procedure)? [closed]

I am taking AP Chemistry, and have noticed that I can identify a polyatomic polar molecule, but struggle to determine which molecule is the most polar given a set of several polar molecules. What ...
3
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2answers
282 views

Does firing a proton beam on water make it acidic?

Lets say I fire a proton beam upon the surface of water. Lets assume I do the experiment in an air-free environment and that the proton beam doesn't reflect off the surface of water. Now, protons, ...
5
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2answers
1k views

Partial Atomic Charge in GAMESS

In GAMESS, a calculation of optimisation gives data about partial atomic charges (like Mulliken or Lowdin charges). Can you please let me know how to calculate the other types of partial atomic ...
4
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1answer
194 views

Detecting a gas molecule moving through a small pinhole

Suppose I have the four DNA base chemicals - thymine, adenine, cytosine, and guanine. Imagine I turn each of them into a gas, make a "cartridge" of the gas for each chemical, and then have a "pinhole" ...
1
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1answer
607 views

Why does rice become sticky after cooking?

Rice when not wet isn't sticky at all. But when you soak it in water for some time it gets sticky. What's the chemical change that occurs in rice that makes it sticky?
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2answers
266 views

finding molar mass of a molecule [closed]

Why is the molar mass of a molecule defined as the the sum of molar mass of all the atoms present in the molecule? For example, suppose we have to calculate the molar mass of $\ce{H_2O} $ molecule. ...
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1answer
169 views

Diatomic and Monoatomic

Why do we represent the molecule of solid metals using the symbol of the element itself(for example ,molecule of iron=$\ce{Fe}$,etc.) whereas we represent the molecule of the elements like oxygen in a ...
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2answers
646 views

Relation between molecule symmetry and crystal symmetry

How much is crystal symmetry dependent on molecule symmetry? Can one make any kind of inferences on the symmetry of the molecule looking at the symmetry of its crystal or the other way around?
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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
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1answer
55 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
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2answers
331 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 ?
2
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1answer
339 views

Lennard-Jones diagram - what is on the x-axis?

I have a Lennard-Jones diagram here where I can't figure out, what is on the x-axis. G. Ertl, Angew. Chem. Int. Ed. 2008, 47 We are looking at a diagram for a molecule $\mathrm A_2$ composed of two $...
12
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1answer
711 views

Existence of Dichlorine Pentoxide

I searched the net and a lot of books, but I was unable to find any information about dichlorine pentoxide. Does dichlorine pentoxide($\ce{Cl2O5}$) exist? If it doesn't exist, then why so? If ...
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0answers
131 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 ...
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0answers
82 views

Are there any reactions where two triatomics form three of the same diatomic?

A chemical equation: $\ce{A}+\ce{B}\to\ce{3C}$ Where $\ce{A}$ & $\ce{B}$ are triatomic molecules and C is a diatomic molecule. Find out $\ce{A}$, $\ce{B}$, $\ce{C}$? So far the most worthy ...
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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?
0
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1answer
550 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
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1answer
397 views

Why is (1E,3Z,5E,7E,9Z,11E)-cyclotetradeca-1,3,5,7,9,11-hexaen-13-yne not antiaromatic?

The compound shown below was synthesized by Professor I M Dimm who was astonished to find that it was exceedingly stable. Prof. Dimm had expected world renown for making what he thought would be an ...
3
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1answer
463 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
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1answer
3k views

How to explain the periodic trends in boiling points in groups?

Observing the trend of boiling points of the compounds listed, choose the appropriate terms to fit into the blanks: \begin{array}{lr} \text{Compound}& \text{boiling point}\\\hline \ce{H2Te} &...
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0answers
82 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 ...
0
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1answer
333 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?
0
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1answer
465 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 ...
3
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1answer
87 views

Calculate the amount of substance of an isotope based on the percent composition

Calculate the amount of substance of $\ce{^37Cl}$ in a $\pu{42.3 g}$ sample of $\ce{Cl}$ containing $24.00\%~\ce{^37Cl}$ and $76.00\%~ \ce{^35Cl}.$ Given the atomic masses $m(\ce{Cl}) =\pu{35.45 amu}...
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0answers
703 views

Molecular weight of Polymers

Addition polymerisation is defined in my textbook as the process in which a molecule or compound is formed by combination of small molecules (monomers) implicitly having greater molecular mass than ...
3
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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?
5
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1answer
723 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
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1answer
323 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
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1answer
239 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 ...
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1answer
156 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
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2answers
777 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 ...