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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1answer
60 views

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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23 views

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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1answer
525 views

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
60 views

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 ...
2
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0answers
50 views

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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33 views

When we tear a piece of paper do some of the molecules fall of as we tear? [duplicate]

So I mean are some of the molecules lost(fall of) while we tear the paper? Or all the molecules present in the sheet of paper just get divided in the two new pieces created?
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32 views

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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2answers
58 views

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?
2
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1answer
102 views

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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2answers
41 views

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 $\pi$ ...
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2answers
169 views

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 ...
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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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1answer
35 views

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! ...
3
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1answer
61 views

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 ...
2
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2answers
77 views

How to quantify the difference between two xyz files for the same molecule?

Sometimes I encounter xyz files with slightly different coordinates, for example, before and after optimization. What is the easiest way to compare how different are they? In the first approximation,...
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0answers
29 views

How to rationalise the resonance structures of nitrogen dioxide?

The following image depicts resonance in $\ce{NO2}$ molecule: I don't know if it is obvious or not, but I'm puzzled by this structure. I've read about the structure of the $\ce{NO2}$ compound, but it ...
4
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2answers
99 views

Long linear molecule with alternating elements? [closed]

In the classic freshman physics text Electricity and Magnetism by Purcell, one of his first examples is the computation of the electrical binding energy of a $\ce{NaCl}$ crystal. He models the crystal ...
3
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2answers
641 views

Which has the greater N–O bond length, NO₂⁻ or NO₃⁻?

Which has the greater N–O bond length, $\ce{NO_2^{-}}$ or $\ce{NO^_3^{-}}$? I don't understand why the N-O bonds should be of different lengths in these two molecules (don't the same bonds have the ...
3
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2answers
1k views

Choose the molecule with the strongest bond

Choose the molecule with the strongest bond: $\ce{F2, Cl2, Br2, I2,}$ or all are equal. All of them are nonpolar-covalently bonded, so I had thought that the answer would be "all are equal". However,...
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1answer
111 views

Do molecules containing only carbon exist?

Why doesnt carbon forms bonds with itself to form a molecule. Carbon shows the property of catenation then why doesnt it form a cyclic molecule as : ...
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1answer
38 views

Are there gases that spontaneously combust when mixed with oxygen? [closed]

Is there a known gas that would combust by there mere action of mixing with oxygen? So, we could put this hypothetical gas in a balloon, and if the balloon popped, it would combust and explode.
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1answer
458 views

Discrete molecules [closed]

I came a across a passage in my textbook on Formula Mass topic which mentioned something about discrete molecules. Some substances such as sodium chloride do not contain discrete molecules as their ...
3
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1answer
126 views

How do I visualise bicyclo[4.4.1]undeca-1,3,5,7,9-pentaene?

While reading my organic chem book, I came across this compound: Since this is an exercise question, I do not know the name of this compound. I am unable to visualize this compound (how it looks out ...
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1answer
58 views

At what temperature can molecules no longer form?

// hyper simplistic terminology in use for the question - apologies. Molecules are formed by atoms bonding together, and those bonds have an equivalent energy. At what temperature does the thermal ...
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0answers
66 views

Calculate concentrations in a system made up of molecules in order to calculate ionic strength

I understand how to calculate ionic strength where there are concentration data in molality or molarity units available and where the system is made up of only two components. However, I have been ...
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1answer
304 views

How many molecules are there in 17.53 grams of NH4ClO4? [closed]

How many molecules are there in 17.53 grams of $\ce{NH4ClO4}$? I get to 1 mol = 118 then I get stuck.
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1answer
229 views

Why are long oxygen chains unstable? [duplicate]

H-O-H (water), H-O-O-H (hydrogen peroxide), H-O-O-O-H, H-O-O-O-O-H, etc. This is analogous to hydrocarbon chains, methane, ethane, propane, butane, etc. Note the Hydroxygen Chains satisfy 2 covalent ...
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74 views

How would you write the empirical formula of an ion?

How would you write the empirical formula of e.g. X2Y42-?
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1answer
66 views

Collision rates between two molecules in a liquid

How would I calculate the collision rate between kaolinite and amylopectin particles in a liquid with a density of ($\pu{1.01g/m^3}$) and a viscosity of ($\pu{0.000434 Pa s}$)? I know this is related ...
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1answer
472 views

Calculating the Radius of a Molecule

Assuming the molecule is a sphere, would the radius of amylopectin be $9.17*10^{-22}~cm^3$? I arrived at this answer by deriving the molar volume by dividing the molar mass ($828.72~g/mol$) of ...
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1answer
70 views

Finding molecules that you randomly create using a modeling kit

I recently bought https://snatoms.com/ (which is just a real-life modeling kit for atoms/molecules) and was just keen on learning about chemistry in general. I often randomly join atoms to make up ...
3
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2answers
1k views

What is the difference between ''1 C atom and 1 mole of C atoms?'' [closed]

Does 1 C atom mean 1 single C atom out of Avogadro's number of C atoms = 1 single C atom out of 6.023 X 10^23 numbers of C atoms? Does 1 mole of C atoms mean Avogadro's number of C atoms = 6.023 X 10^...
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1answer
184 views

What to say 'one mole of C atoms or one mole of C molecules?

What to say 'one mole of C atoms or one mole of C molecules in CO? Please point out if I am wrong here As we know, one molecule of CO = one mole of CO molecules = 6.223 X 10^23 number of CO molecules ...
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1answer
65 views

Is a non-compound molecule a chemical substance?

The Wikipedia definition of chemical substance states: A chemical substance, also known as a pure substance, is a form of matter that has constant chemical composition and characteristic properties....
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3answers
2k views

How is sulphur trioxide formed and why is it stable? [duplicate]

Structure of $\ce{SO3}$ (sulfur trioxide): In the molecule, if each oxygen atom shares two electrons with sulfur atom then how does the sulfur atom remain stable? It already has 6 valence electrons ...
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1answer
87 views

Calculate the formula, and moles

If $\ce{1.84\times10^{-4}}$ moles of element A was completely reacted with element B to create $\ce{1.231\times 10^19}$ molecules of $\ce{(A3B2)_x}$ a hypothetical compound, what is the value of x? I ...
2
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1answer
688 views

Do alkali metals not form diatomic molecules?

I know hydrogen forms a diatomic molecule $\ce{H2}$, where the electronic configuration of hydrogen is $\ce{1s}$. But why doesn't lithium also form a diatomic molecule? Its electronic structure is $\...
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2answers
935 views

Are the breaking of bonds simultaneously endothermic and exothermic? [closed]

I understand that energy is NEEDED to BREAK bonds. But don't chemical bonds already have some form of potential energy in them already? So wouldn't it make sense that even though energy is required to ...
2
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0answers
63 views

Can the friction of air disintegrate objects if they are accelerated enough?

Can an object be thrown so fast that the individual atoms or molecules separate in air? I mean if you could accelerate an object fast enough, would it disintegrate from the friction of air? If so, ...
2
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2answers
138 views

A mole of atoms is the number of atoms whose total weight equals the atomic weight?

My textbook says, a mole of atoms is the number of atoms whose total weight = the atomic weight. There's something in the definition that's confusing me. Now what is confusing me is: Atomic weight =...
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1answer
135 views

Identification of an aromatic compound for a quiz [closed]

I need help identifying this structure for a puzzle. Original text was blurry, so a white overlay was added for readability, though some fragments might be different. Any help or suggestions are ...
3
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1answer
55 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], ...
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1answer
2k 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
661 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
342 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
93 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
6k 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
429 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
2k 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
397 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 ...