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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Why do the moles of hydrous molecules change so easily? [closed]

I think it is because the water may dilute the solution?
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Is it possible to achieve a level of “truly zero” concentration? [duplicate]

If we take some aqueous solution and dilute it further and further, will the concentration of the solution ever get to zero? I would say no, simply because total dilution implies that all the ...
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Rules to follow while writing a chemical formula for polyatomic ions

In Science, textbook for class IX, chapter $3$ [1,p.38], it states: The rules that you have to follow while writing a chemical formula are as follows: in compounds formed with polyatomic ions, the ...
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Different molecular orbital diagrams for different elements [closed]

I was wondering why the molecular orbital diagram for elements greater than 14 is different from the diagram for elements with atomic number less than or equal to 14? This has been bugging me for a ...
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How does pressure affect chemical bonding? [closed]

The molecular theory of friction says that friction arises as a result of bonding between the suface molecules in contact... When we push a body, these bonds are stretched much like in a spring and ...
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Process of a substitution reaction

In this question I am not able to decide by what process this reaction is happening. I first thought that one of the $\ce{H}$ from $\ce{CH3}$ will depart $\ce{Br}$ from $\ce{CBrCl3}$ but I am wrong. ...
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The Solubility of Tyrosine

I find very little data on the solubility of tyrosine, other than that it has a very low solubility at room temperature for an AA. (1) Does anyone know different ways to dissolve fair amounts of it in ...
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How is bond length of C-O and C-N same?

In NCERT and many other books it is given that bond length of $\ce{C-O}$ and $\ce{C-N}$ is same. But, how can it be possible as size of oxygen is smaller than that of nitrogen so bond length of $\ce{C-...
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Can pthalic acid or 1,2-Benzenedimethanol be possible products of Cannizzaro reaction of phthalaldehyde?

I know the main product that is ortho-hydroxymethyl benzoate ion but I think that phthalic acid and catechol must be formed also in very small amounts but I am unable to get any confirmation from the ...
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SMILES string convertors

I'm new to SMILES strings, and have noticed that they're not standardised. Firstly, what is the reason for different structures of SMILES strings to represent the same compound? Why not have a ...
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How to draw the 2D representation of ammonia molecule

In the 2D representation of the ammonia molecule, we see one solid line, one solid triangle and one dashed triangle A plane can be made to pass through any three given points. In other words, we can ...
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Stability of Peroxynitric Acid in cold temperature

I have a question about the stability of Peroxynitric Acid i.e. $\ce{HO2NO2}$ at cold temperature. I know that it becomes stable when temperature decreases, but what is the specific reason for it? I ...
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Origin in a crystal

I am trying to understand the International Tables for Crystallography. How can I identify the origin in the image on the left? Without knowing the origin, I cannot identify the position of the ...
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Linear molecule that is liquid at room temp. and pressure?

I am trying to find a linear molecule that is a liquid at room temperature and pressure. Do you know of any? By linear I mean that all the bonds are co-linear (ie. simple alkane carbon chains don't ...
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Is there any elemental molecule which does not react well with anything but oxygen? [closed]

For example, phosphor reacts with oxygen but it also easily reacts with many halogens, metals, etc. Is there any elemental molecule that doesn't react well with almost anything but oxygen?
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Short description for destriptors output by PaDEL-Descriptor

I am trying to implement this paper & it uses PaDEL-Descriptor to get additional features. To be specific they extracted: Bond count: number of single, double, triple bond including and excluding ...
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1answer
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Determine and draw planes and axes of symmetry of a molecule using software (VESTA or Mercury)

I designed the $\text{MoS}_2$ molecule (bilayer), with polytype 2H in the VESTA. My goal is to draw the plans and axes of symmetry of the bilayer set. According to the information in the literature, ...
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Breaking bonds with magnetic fields

I was wondering if we could break a bond by applying a big magnetic field on a molecule. The magnetic would just cause the spin of cores of the atoms making the molecule to be aligned , raising the ...
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What is the general or ideal equation for the radial wave function?

I came across this question on the internet: What is the value of $(n + l + r)$ in a given wave function, where $n =$ principle quantum number and $l =$ azimuthal quantum number and $r =$ total ...
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Finding Symmetry number of a molecule [closed]

An isotopic variant of the molecule SF$_6$ is S$^{19}$F$_4^{18}$F$_2$, with the two $^{18}$F nuclei oriented axially, so that the $^{18}$F-S-$^{18}$F angle is 180°and the four $^{19}$F nuclei form a ...
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Problem calculating relative molecular mass [closed]

I am starting be re-learn Chemistry after several years. The Book I am using has a test question to calculate the relative atomic mass of: $ (CH_3CO)_2O $ My take Carbon C, $ A_r = 56 $ Hydrogen ...
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1answer
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What is the largest, noncrystalline, non-polymer inorganic molecule?

A question came up in class from one of my chemistry students. He asked what the largest, non-crystal, non carbon-based, molecule is. We ruled out complex proteins, DNA, and other polymers, as well as ...
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Do molecules with bridges through rings exist?

Do molecules with bridges through rings (in a manner illustrated by this) exist? I sometimes get results like this when doing Energy Minimization on molview.org. For example: Is this actually a ...
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What will be the number of molecules per mole in a set of different gases when compared with hydrogen? [closed]

The source of my question is due the nature of a problem which I found misleading in the way how it was presented. The problem is as follows: The molecular weight of hydrogen ($\ce{H2}$), helium ($...
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What is maximum energy level of molecules?

I have been reading about the relation of molecular graph spectrum, that is, the set of eigenvalues of the Laplacian matrix of the molecular graph, and molecular properties. Recently, I came across a ...
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Kinetic Theory of Gases and molecular velocities of gases [closed]

The assumption that molecules collide with elasticity was postulated in the kinetic theory of gases. So my question is molecules should have higher tendency to collide obliquely and would therefore ...
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1answer
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Why are moles of compounds have only 6.022x10 23 atoms? [closed]

I am a bit stuck on a basic chemistry concept. I understand that the Avogadro number indicates the number of chemical entities it has (ion, molecule or atom) What I don't understand is that when you ...
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1answer
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Identifying molecule with three adjacent six-membered rings from blurry image

I have found this isolated image on one of my old hard drives and I would like to know what molecule does the image represent:
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Which biphenyl is optically active?

Which biphenyl is optically active? I know that it can never be 1. I don't think it will be 4 either as I read that it should be ortho-substituted biphenyl. So, when I look at 2 and 3, I can't make ...
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1answer
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What is the use of both mol and mass representing the same thing i.e. amount of something? [closed]

A mol is a unit but also has a magnitude. How can a unit have a magnitude? And if mole is used to measure an amount of substance than what does mass measure?
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If cigarette smoke is exhaled, what happens to the accompanying exhaled breath?

I want to know what happens to that breath. To help you answer this question, consider in your mind these subquestions: Is there a necessary principle at work, by which you know that it vanishes/...
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Kinetic Diameter: How to calculate it? Pressure influence?

Wikipedia states: Kinetic diameter is a measure applied to atoms and molecules that expresses the likelihood that a molecule in a gas will collide with another molecule. It is an indication of the ...
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Database for experimental diatomic ionization energies

I am looking for a database, in which the experimental ionization energies (and e.g. heat of formation) of atoms and diatomic molecules are listed as files. If it comes with a Python package, that ...
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1answer
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Can atomicity be infinity? [closed]

My chemistry teacher told us that graphite or diamond had an atomicity of infinity. However, the definition of molecule in my testbook is A molecule is the smallest part of an element or compound ...
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1answer
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Software that determines whether a molecule can exist and draw it from a formula?

I have run calculations that predict atomic configurations. As a simple example, in a system that contains H and O, I might get a list like: ...
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Molecular formula with CH without numbers [closed]

I was wondering if there exists a compound, the molecular formula for which includes CH but does not include any numbers. Like ...
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What is this fluorinated organic substance?

The corresponding author of the paper where this formula was published as appendix passed away. Can someone help me with identifying what is the name of this compound and why have strange zig-zag ...
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How one can calculate Si-O-Ca/Mg valence angle energy?

I want to perform the relaxed scan (or relaxed surface scan) for the valence angle energy of Si–O–Ca, Si–O–Mg, Al–O–Ca, and Al–O–Mg. I will use DFT (ORCA), probably B3LYP and triple zeta basis set (...
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What is kekulization (in RDKit)?

It's been a while since I've studied chemistry. Now, I am reading the documentation of RDKit. At a certain point, the term "kekulization" is mentioned. What is kekulization (in RDKit, if this is not a ...
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1answer
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What is a molecule’s smallest set of smallest rings?

It is been a while since I've studied chemistry. Now, I am reading the documentation of RDKit, where they mention the expression "smallest set of smallest rings" (SSSRs). I understand that a ring is a ...
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Is water the most common multielemental compound?

Water is a very common substance, not just on Earth, but also in space. Although water usually occurs in space as a solid and occasionally as a gas and relatively rarely as a liquid, the most common ...
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What is molecular potency?

In the paper Junction Tree Variational Autoencoder for Molecular Graph Generation, the authors propose a ML model that is based on the message passing neural network, variational auto-encoder, the ...
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Is the molar mass of a molecules lowered by the binding energy of the chemical bonds?

When calculating the molar mass, is there any measurable difference in total mass of the molecule due to the loss of binding energy?
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What do we learn from an isotope peak (or M+2 peak) in a mass spectrum?

Mass spectrum of a molecule showed molecular ion peak and its isotopic peak in 1:1 ratio. What is the possibility of the atom present in the molecule? Since it is mentioned that it has a ...
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Predict the number and nature of bonds using Molecular Orbital Theory

I found the following question in a high school chemistry problem book: According to Molecular Orbital Theory which of the following is true: (A) In $C_2$ molecule both the bonds are $\pi$ bonds. (B) ...
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How to determine the boiling point of substances? [closed]

Which of the substances has the lowest boiling point? a) $\ce{H2O}$ b) $\ce{H2S}$ c) $\ce{H2Se}$ d) $\ce{H2Te}$ I've been searching for any formula or rule to determine this, but I read that it didn'...
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Molecular weight of NiMnGaFe compund problem

I have a big problems calculating molar/molecular etc masses, because in my case I have a monocrystal, co I cannot imagine it as a molecule and my compound is made of Ni-Mn-Ga-Fe. I know the mass and ...
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Why can you blow bubbles in milk but not hot cocoa, which is milk based?

My daughter is asking this question and I’m assuming it’s something related to the cocoa added to milk but don’t know what change is happening molecularly and why it would affect the bubbles. Thanks! ...
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Is the existence of chirality center equivalent to chiral?

To make my question more clear, I want to ask two questions: Is it possible for molecule to be achiral even though molecule has chirality center? Is it possible for molecule to be chiral even though ...
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1answer
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What would be the name of this compound? [closed]

Although I assume this compound is likely unable to be formed, my chemistry teacher put it up on the whiteboard to show the extent of what you can name using IUPAC nomenclature, out of interest I ...

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