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 ...

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2
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0answers
35 views

Amplitudes and phases of transform of an image

I have recorded an image of a large macromolecule and after several types of image analysis, have obtained a rotationally averaged image, that is not quite perfect, but appears to show 6-fold ...
0
votes
1answer
41 views

How to represent a 3D model of cocaine?

For my AP Chemistry class we were told to make a molecular diagram that was "better than excellent" and the rest is up to us (we could choose the molecule and how we wanted to represent it). My group ...
1
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1answer
36 views

Volume Of A Nitric Oxide Molecule [closed]

So 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 ...
-3
votes
1answer
55 views

Mass of “orange” in 25% orange juice [closed]

Hypothetical question: Knowing that orange juice has 25% concentration of orange. And knowing mass of juice which is 200g. What ...
-1
votes
1answer
31 views

On the molecular level, how do catalysts work?

I already know what catalysts do (lower activation energy requirement for a reaction), but how exactly are they able to do that (on a molecular level)?
10
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7answers
2k views

Are there any good examples of commonly ingested molecules that contain particular toxic individual elements?

In the house on my own and an article popped up on my feed with the following statement: While the Government has insisted the chemical is safe, cadmium is recognised as a cause of lung cancer ...
-2
votes
2answers
63 views

Why is O2 enough to form a mole of Oxygen? [closed]

I understand that this is the most basic knowledge of moles, however I'm still unsure - according to easy research, $\ce{O2}$ forms a mole of Oxygen. As a mole is $6.022*10^{23}$, exactly what on the ...
2
votes
2answers
43 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 ...
2
votes
1answer
60 views

Is oil shinier than water? Why?

The physics part: The part that talks about being shiny, I agree, is mainly physics. But proceed in my question, and you'll see how it's a chemistry one. We know things are shiny if they either ...
2
votes
1answer
70 views

Volume of 1 Mole of Liquid Water

I am doing some rough calculations to test my understanding of elementary chemistry. In what follows, I calculate the volume of one mole of liquid water at about $4~^\circ\mathrm{C}$ and ...
2
votes
1answer
39 views

Do molecules with carboxyl groups have properties of carboxyl's sub-functional-groups?

We're learning about functional groups of different organic molecules, and there are some I'm confused about: carboxyl, carbonyl, and hydroxyl. I was looking online but I couldn't find a direct answer ...
1
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0answers
34 views

First ionization energy of hydrogen molecule

If we have the dissociation's energies of hydrogen molecule $H_{2}$($D_{0}$) and the corresponding molecule ion $H_{2}^{+}$ ($D_{1}$) together with the first energy of ionization of hydrogen atom ...
0
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0answers
35 views

Molecular structure of all periodic table element molecules exceptional cases etc

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 ...
4
votes
3answers
76 views

Can a single monomer be a macromolecule? If so, when?

In our science class, we're learning about the four fundamental macromolecules in every living organism: carbohydrates, proteins, lipids, and nucleic acids. Our class definition of a macromolecule ...
6
votes
2answers
136 views

How to know whether s-p mixing will happen in heteronuclear molecules?

How do I know whether s-p mixing would occur in some diatomic heteronuclear molecules like CN, CO, NO etc?
5
votes
2answers
597 views

Using MO theory, give an explanation for the C-C bond length in cyanogen

1. The problem statement, all variables and given/known data 2. The attempt at a solution I know that the MO diagram for CN- is this: I am unsure how to draw the MO diagram for cyanogen. I know ...
2
votes
1answer
682 views

Draw a simplified MO diagram for the pi system of Methyl vinyl ether

My attempt at the answers: i) 2 bond pairs and 2 lone pairs on oxygen atom therefore bond angle of slightly less than 109.5 degrees, around 104 degrees. ii) 120 degrees bond angle therefore sp2 ...
10
votes
1answer
417 views

Why six C atoms are usually seen in cyclic compounds?

When it gets to Carbon-based molecules, one very possible structure when there are more than six C atoms is the hexagon; though not mostly perfect, it emphasizes that six Carbon atoms tend to bond ...
0
votes
1answer
13 views

Does STED microscopy allow us to see reactions happening on a substrate

This years nobel prize for chemistry went to nanoscopy using STED as a control mechanism. I have seen the atoms/molecules of a lattice vibrating as shown by Stefan W Hell in a presentation at some ...
1
vote
1answer
40 views

Stereo Isomerism - syn/anti

I was studying the types of stereo-isomerism E-Z, Cis-Trans and then I come across syn-anti stereo-isomerism this one is giving me a bit of fight in understanding, especially where lone pairs are ...
16
votes
2answers
791 views

Proper typography of “NOx”

I am a journal typesetter, and recently I came to a problem that I'm not sure I know to solve. The question is how to properly typeset the "NOx" abbreviation for nitrogen oxides. Which is ...
4
votes
1answer
89 views

Why is water transparent?

Some substances like Copper Sulfate for example have vivid colors. But why is water transparent? Does it not emit any visual light from the electromagnetic spectrum?
-1
votes
1answer
69 views

How would you find the mass in grams, if you only know the number of particles of a portion of the formula?

If you were given a question like below: What is the mass in grams of a sample of $\ce{Fe2(SO4)3}$ that contains $3.59 \times 10^{23}$ sulfate ions, $\ce{SO4^{2−}}$ ? The molar mass of ...
0
votes
1answer
17 views

definition of relative atomic mass

I found out there are 2 definitions of relative atomic mass. First definition is Ar is the mass of 1 atom of an element relative to 1/12 the mass of carbon-12 atom. It can be found in any chemistry ...
0
votes
1answer
302 views

Chemical composition of petrol

What is the chemical composition of petrol? What are the molecular available in petrol? Some time which is marked with 95% octane. So what is the remain element occupied 5%?
0
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0answers
35 views

Relating Molecular Orbital Theory and Valence Bond Theory

As I have studied both the theories only superficially, I am unable to correlate them. I would like to know the link between the two.
0
votes
1answer
58 views

Molecular Orbital Theory and No. of bonds

The order of filling of molecular orbitals $\ce{O2}$ by MOT is this : But from it, how can I deduce that there is one sigma and one pi bond in an oxygen molecule ?
2
votes
2answers
32 views

How can we confirm the number of protons in an atom?

The periodic table tells us that there are 6 protons in a carbon atom. Is there a way to verify this first-hand? Or are we just expected to believe it unquestioned?
4
votes
1answer
2k views

What holds atoms together?

1.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? 2.How are molecules of ...
-1
votes
1answer
55 views

Dipole, Symmetrical, ASymmetrical [closed]

I don't understand what a dipole is, I kind of have an idea but not exactly. Also, how do you know if a molecule is Symmetrical or ASymmetrical. For example, the following: $\ce{O2}$ $\ce{H2O}$ ...
1
vote
1answer
228 views

Converting from Grams to Molecules

I was doing some problems from the textbook on converting between units using dimensional analysis and I came across this problem. A vat of Hydrogen Peroxide ($\ce{H2O2}$) contains 455 grams of ...
4
votes
3answers
170 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 ...
2
votes
1answer
49 views

Find the partial pressure in a container

I have an air mass which consists of 78.1% $\ce{N_2}$, 20.9% $\ce{O_2}$, 0.964% $\ce{Ar}$, and 0.0378% $\ce{CO_2}$ in a container which volume $\mathrm{V=40~L}$ at a temperature $\mathrm {T = ...
3
votes
1answer
85 views

Electrolysis of Beer

Electrolysis of water, means that the water is separated into hydrogen and oxygen. As beer also includes water, I initially thought electrolysis of beer would cause the water to separate, and the ...
2
votes
1answer
67 views

Can you calculate the properties of a substance based soley on its atomic properties?

I'm trying to write some software that I can use to determine, roughly, what the physical properties of a pure substance are. I know I could just use a database of the known properties of each ...
0
votes
1answer
29 views

Chemical nomenclature of ions

I'm a very beginner in chemistry. The book I'm studying says that an ion is an atom, or a collection of atoms, that has an electric charge, then it writes about the difference between molecules and ...
3
votes
2answers
71 views

Why does water break salt really

A kid asked me this question just the other day, and I said that the positive part of $\ce{H2O}$ attracts the negative $\ce{Cl}$ ion and the negative part of the $\ce{H2O}$ attracts the positive Na ...
2
votes
1answer
51 views

About the way chemicals and molecules are represented

The standard way of representing molecules with letters like $\ce{C}$ for Carbon, $\ce{O}$ for Oxygen etc.; and a lot of lines and double lines like a graph from Graph theory where each letter is a ...
3
votes
1answer
619 views

Phenyl vs phenol functional group?

Phenyl is a functional group with an aromatic ring bonded to another group. And, phenol is a molecule that is just a phenyl bonded to a hydroxyl group. However, some sources consider phenol itself a ...
4
votes
2answers
132 views

Nitrogen dioxide dimerization

$\ce{NO}$ can't dimerize and that is explained because the free electron is in an antibonding orbital. The same is true for $\ce{NO2}$, but it can dimerize, how?
3
votes
2answers
1k views

Why are least electronegative elements usually in center of lewis structure

Many sources state that one of the primary rules for molecular structures is that the least electronegative element is in the center. However, none of them explain why this is the case. Is this ...
2
votes
2answers
58 views

Why is it O-Cl-O and not O-O-Cl?

I'm currently preparing my exam and while I did never think about this question during the course, it begins to confuse me right now... Why is it the structure of $\ce {ClO_{2}-}$ like $\ce {O-Cl-O}$ ...
1
vote
0answers
27 views

H2, dipole transitons [closed]

I'm a not a chemistry expert, so please forgive me if what I write is not entirely correct. I come from an astrophysics background and in several astrochemistry papers it is mentioned that dipole ...
0
votes
2answers
45 views

Molecules that get charged in Water

I am a chemistry super noob and I was watching a MIT video where the professor states that: "Certain molecules become charged when they come in contact with water in the natural state" Can someone ...
2
votes
1answer
235 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 ...
1
vote
0answers
53 views

Invariants in chemistry used for model selection

What invariants related to geometrical structures that describe molecular geometry are used in chemistry? Explanation: Here, Electronic model with highest prediction rate…, one can learn about ...
4
votes
1answer
94 views

IBrF2 - van der Waals repulsions - and number of unique bond angles

I understand that the molecule $\ce{IBrF2}$ is T-shaped, with three ligand atoms and two non-bonding pairs. However, how many unique bond angles can this molecule exhibit? My professor argues for ...
1
vote
1answer
84 views

Greater entropy: an atom or macromolecule?

A question that appeared on my last chemistry exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size ...
3
votes
1answer
63 views

Oxidation numbers of phosphorus pentachloride

I read detailed explanations of what oxidation numbers/ states represent and it boils down simply to this: If it's positive, it shows how many electrons the element lost, and in the case of a negative ...
2
votes
1answer
52 views

What is molecular system in general terms? What is a supramolecular system?

What is a molecular system in general terms? Could the solution of sugar in water be called a molecular system, if we were not interested in sugar-water interaction? Today Jean Marie Lehn told me ...