Tagged Questions

A molecule is an electrically neutral group of two or more atoms held together by covalent chemical bonds

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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 ...
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20 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%?
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0answers
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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.
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1answer
20 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 ?
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2answers
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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?
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422 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 ...
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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: $\ce{O2}$ $\ce{H2O}$ ...
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1answer
63 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 ...
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3answers
128 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
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1answer
45 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 = ...
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1answer
47 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
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1answer
57 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 ...
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1answer
26 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 ...
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2answers
57 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
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1answer
48 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
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1answer
204 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 ...
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2answers
57 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?
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2answers
531 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 ...
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2answers
54 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 $\ce {O-Cl-O}$ ...
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0answers
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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 ...
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2answers
43 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
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1answer
120 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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0answers
52 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 rateā€¦, one can learn about ...
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1answer
82 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 ...
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1answer
61 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 ...
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1answer
43 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 ...
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1answer
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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 ...
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1answer
96 views

How can a chemical structure be stored in a matrix?

How do I represent a chemical structure in a matrix format in Matlab? Can I input a chemical structure into Matlab using the S.M.I.L.E.S notation? I have to specify the connectivity of different ...
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3answers
80 views

What does 'organic/non-ogranic molecule' means exactly?

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 ...
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1answer
223 views

How does the pyramidalization effect the bonding angles in a distorted octahedral environment?

This is a follow up on "Generally Octahedral - Meaning?". Since Dissenter asked in the comments to my answer: I'm not sure why the $\ce{F_{eq}-S-F'_{eq}}$ bond angles would be compressed, even if ...
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1answer
69 views

Molecular orbitals and “generalized” aufbau principle for heteronuclear molecular configurations

Is there any general ordering or rule for heteronuclear molecules like $\ce{AX_2}$, $\ce{AX_{n}}$, and their molecular bonding/antibonding configurations ($\sigma/\pi$ orbitals) accordingly to some ...
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1answer
44 views

Relationship between Van der Waals forces and the boiling point

Choose the right answers in the following statement: The boiling point of a liquid substance is higher as the Van der Waals forces (in/between) the molecules of the substance are (lower/higher). I ...
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0answers
40 views

Argon chemistry, molecular geometry and hybridisation

Can Argon hybridize orbitals and/or form covalent-like/ionic-like compounds? Is there any study of that?I would be happy to read concrete references... What kind of molecular geometries for argon ...
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3answers
85 views

Any FREE chemistry software to view molecule pictures in explorer

I am testing my small api library that generates lots of chemical files such as MOL and SDF. I was wondering if there is a software that can show me the pictures of chemical structures inside each ...
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1answer
140 views

Calculate the number of moles of phosphorus in 15.95g of tetraphosphorus decaoxide

I've got this question and I cannot figure out how to get the correct answer. Calculate the number of moles of Phosphorus in $15.95\:\mathrm{g}$ of tetraphosphorus decaoxide. ($\ce{P4O10}$) I tried ...
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1answer
62 views

Existence of Hyponitrite Molecule

Does the hyponitrite molecule exist? I know the hyponitrite ion exists (http://en.wikipedia.org/wiki/Hyponitrite) but what about the molecule? I have found no reference to the molecular form on ...
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1answer
63 views

In which of the following chemical compounds are the building blocks molecules?

In which of the following chemical compounds are the building blocks molecules? (A) $\ce{AgNO3}$ (B) $\ce{HNO3}$ (C) $\ce{KNO3}$ (D) $\ce{NaNO3}$ (B) is the correct answer, but I have ...
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3answers
48 views

Reduce sizing of molecule - Oxygen

Can the size of molecule oxygen reduce smaller? If yes, how is that possible? Is it related to proton and electron surrounding the nucleus?
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1answer
92 views

Fractional Bond Order - How to Visualize?

Consider nitric oxide, which has a real bond order of 2.5, contrary to what this UC Davis rendering might imply: What's the best way to visualize a molecule with a fractional bond order? What ...
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2answers
288 views

What is there in this 3D representation of organic molecules I fail to grasp?

I think there's a basic idea I'm missing about 3 Dimensional representation of molecules. I think it may be about converting to Fischer representation. Consider the following two products of ...
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2answers
154 views

How can we rationalise the amount of crystal water in coordination complexes?

I was wondering why specific number of water molecules are attached to salts like $\ce{CuSO4.5H2O}$? Searching gave me a satisfying picture : I think $\ce{FeSO4.7H2O}$ should have a similar ...
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2answers
59 views

Calculating the mass in g of a molecule [closed]

If I have the amount of the molecule in moles, how do I calculate the mass of an individual molecule? For example, if the molecule was water?
3
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1answer
63 views

What attributes cause a substance to be nonconductive or conductive

I understand what causes elements to be conductive or nonconductive. But what causes a substance say rubber to be nonconductive at a molecular level?
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4answers
103 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 $\ce{SO3}$ (sulphur ...
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3answers
126 views

Would decomposing an object into molecules be an environmental problem?

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 ...
2
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1answer
132 views

UV radiation on IBr (Radical Substitution)

I came across a radical substitution which Methane reacts with $\ce{IBr}$ to form iodomethane and hydrogen bromide and many more products. I understand the whole process but I don't quite see how the ...
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2answers
98 views

How does glue work?

Simple question. How does household glue work? How does it attach to almost any other compound? Thanks.
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1answer
71 views

what is the name of the molecule that has the greatest number of different atoms? [closed]

What is the name of the molecule that has the greatest number of different kinds of atoms? For example, H2O is water has 2 different kinds of atoms which are H and O. For example, C6H12O6 is ...
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1answer
187 views

If you try to use the VSEPR model to predict the molecular geometry of XeF6, you run into a problem. What is it?

A. If you try to use the VSEPR model to predict the molecular geometry of XeF6, you run into a problem. What is it? B. What could you do to resolve the difficulty in part A? C. The molecule IF7 has a ...
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1answer
60 views

How to estimate the dielectric constant of a liquid?

Are there any approximate relationships between the (static) dielectric constant of a liquid and properties of the individual molecules? For example, suppose I know the polarizability and dipole ...