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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15
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1answer
836 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 ...
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 ...
10
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1answer
300 views

Standards for drawing chemical molecules

I'll preface this by saying I haven't had a chemistry class in 10 years and molecular structures are not my thing. But I'm submitting a revision to a journal paper where I need to include figures of ...
20
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2answers
5k views

Which relatively simple molecules violate the octet rule?

I'm learning how to draw Lewis diagrams. Everything I've read emphasizes the octet rule. However, to the best of my knowledge, that rule only applies to elements in the first three periods. On our ...
8
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3answers
6k views

What is difference between intramolecular redox and disproportionation redox

I can not understand difference between the intramolecular redox reaction and the Disproportionation redox reaction. Both involve the same molecule as substrate, but what is difference?
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,...
4
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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 ...
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 ...
6
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2answers
114 views

What's the reason for discrepancy between DFT calculated image and NC-AFM-acquired one in this article?

Looking at the images in this article, I've noticed that the molecule electron density images showed as calculated via DFT look very symmetric, while those obtained by NC-AFM appear somewhat distorted....
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2answers
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Why do single elements in a molecule have an oxidation state of zero?

For example, take $\ce{O2}$. 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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2answers
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What causes spray cans to get cooler when shaken?

I've been searching the web for this phenomenon and surprisingly I found only one post about it. And the reply to this question about canned air begins with words: I don't know about the shaking ...
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5answers
3k views

What actually is the Wavefunction?

I am aware that the square of the Wavefunction gives the probability density of finding an electron at a particular point in space. I have also heard that it's a complex number but since it's a ...
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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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5answers
7k views

Can fluorine act as the central atom in interhalogen compounds?

Why can't fluorine be the central atom in inter-halogen compounds? A $\ce{F-F}$ bond is weaker than a $\ce{F-X}$ bond and thus, fluorine should be happy to form inter-halogen compounds. But, why ...
-3
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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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345 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 ...
2
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2answers
195 views

How to calculate a rough estimate for the volume of a nitric oxide molecule?

I was wondering what would be the best way to calculate a rough estimate for size of a nitric oxide molecule to use in comparison to a box. I was thinking volume would be the best method, but this ...
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 ...
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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 ...
2
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1answer
129 views

Sugar dissolution test

Is there a way to detect whether sugar is completely dissolved in a cup of water other than looking at the bottom of the cup? I was wondering if there is a test or something that can be carried out ...
3
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1answer
516 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 ...
20
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4answers
404 views

How to explain the concept of mol and reactions involving mol quantities

From time to time I do little pro bono lessons for second grade in math, physics, and chemistry. Recently I came across this question. In a container is $2~\mathrm{mol}$ of $\ce{SO3}$ (sulfur ...
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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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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 ...
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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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, ...
8
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3answers
26k views

How to get the valencies of elements?

How to find the valencies of elements by using its distribution of electrons? Please explain the method in simple words. Do you have to study the valencies or is there a simple way of remembering? PS:...
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}...
5
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2answers
230 views

For a given teabag and dunking duration - will I get more caffeine in a bigger cup or the same amount?

When choosing a cup of tea, I can choose a big cup or a small cup. I'm wondering if I get more caffeine with the bigger cup or the same amount of caffeine. (in moles) My question is: For a given ...
4
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3answers
633 views

What are dipole moments in a molecule supposed to act upon?

In a $\ce{CO_2}$ molecule, a total of four electron pairs are shared between the carbon and oxygen atoms, such that 2 pairs are shared between the carbon atom and each oxygen atom. Oxygen has a ...
0
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2answers
189 views

Would decomposing an object into molecules be an environmental problem? [closed]

In a thought experiment, a friend proposed to me a machine capable of decomposing any object (e.g., a brick) into its molecules. I'm not a chemist or physicist, but my initial reaction was that this ...
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1answer
4k views

Molecular structure of all periodic table element molecules exceptional cases etc [closed]

I am searching about some basics in chemistry. I was looking for the molecular structure of all periodic table element molecules. eg: Hydrogen molecule: as $\ce{H2}$; structure: I was able to find ...
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2answers
4k views

Tool that generates electrostatic maps of molecules?

Do you know any tools that generate electrostatic potential 2d maps of the molecules as an image?
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" ...
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3answers
237 views

Simple enantiomer in powder form?

I want to do some experiments on enantiomers. As it involves some calculations of potential energy surfaces, I would like to do this experiment on a simple enantiomer (For example $\ce{CHBrClF}$). But ...
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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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2answers
644 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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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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1answer
171 views

Can you artificially create molecules with a machine?

Is it possible to create molecules with machines? For example: you shoot one oxygen-atom $(\ce O)$ on one diatomic hydrogen $(\ce{H2})$ to create one water molecule $(\ce{H2O})$.
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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. ...
-2
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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 ...
3
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1answer
2k views

Difference between torsion, out of plane, coplanar and perpendicular bends?

In Infrared spectroscopy, stretches are easily understandable. But, how do I visualize (or conceptually understand) the difference between dihedral (torsions), out of plane bends, coplanar bends, and ...
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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 ?