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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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Does partial charge violate the law of quantization of charge?

Well, we know that charge is quantized. Quoting wikipedia below, Charge quantization is the principle that the charge of any object is an integer multiple of the elementary charge. And we know ...
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2answers
582 views

How well known is the formula of carbonic acid? [closed]

My chemistry teacher in high school didn't know the formula for carbonic acid, which struck me as something someone with a degree in chemistry (as they allegedly do) should know instantly, or at least ...
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3answers
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how to determine which gas would have the lowest pressure

If the volume of each sample of gas was reduced to one-tenth of its original size and the temperature remained the same, which gas would have the lower pressure. I'm getting confused because my ...
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2answers
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Oxygen in water: How is it single if it's always double?

This is simple question, I think. At college (I'm an Intro Chem. student), the professor explained that oxygen is always found in molecules of 2 oxygen atoms combined together - $\ce{O2}$. On the ...
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2answers
281 views

Molecule with 13 total electrons

Is there a stable molecule with total number of electrons equal to 13? Molecule can be either organic or inorganic
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1answer
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Are all organic molecules with odd-numbered electron count radicals?

This question was triggered by another question on this site, about molecules with a total number of 13 electrons. I couldn't think of any (except the boring answer of $\ce{Al}$), and the answers to ...
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2answers
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How does molecular structure affect physical properties?

The question sounds vague and non-specific because my background in chemistry is limited to undergrad college courses. However, I am interested in learning the correlations between the atom-by-atom ...
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1answer
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Why doesn't EDTA have a double bond?

EDTA (Ethylenediaminetetraacetic acid) has a structure like this But why, as the name 'Ethylene' suggests, doesn't it should have a double bond between carbons?
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1answer
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Non polar molecular and attractive forces

How come when a non polar molecule increases in size, the attractive forces between the molecules of a substance also increase? I thought that when a molecule increases in size, the atomic radius ...
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1answer
130 views

Atomic properties [closed]

This may be a very broad question. I always asked myself how scientists manage to find out the exact molecular structures of for instance water or carbohydrates. How do they know? How do they know the ...
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1answer
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Torsion angle symbol

I'm reading up on molecular modelling and have come across some terms I should probably have learnt a long time ago but always scared me off a bit with the Greek letters. I guess I'm a big boy now so ...
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1answer
450 views

Why polymorphs form?

We always hear about the different arrangements of molecules that lead to the formation of polymorphs, my question here is why would a polymorph form in the first place? The material was given enough ...
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1answer
8k views

I need to make a solution with a specific concentration. How do i find the mass?

I have to make a 250 mL solution of $\ce{Mg(NO3)2}$, the concentration of the solution has to be 0.3 mol/L. How can I find out the mass of how much $\ce{Mg(NO3)2}$ I need to use?
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Egg-Detection in Pastries: An Analysis in Heat-Alterated Molecule Identification

I would like to know if anybody here knows of a method to detect the presence of ovalbumin--or any unique, egg-related molecule, in a baked good. Here I am anticipating that the "unique egg-related ...
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1answer
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(Organic Chemistry) Common Atoms in Organic Molecules [closed]

What are 6 atoms commonly found in organic molecules?
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2answers
390 views

How are pure substances (elements, compounds, etc) produced? [closed]

How are large quantities of the substances we use in the lab generally produced? (As in the process from getting the stuff out of the ground to use in the lab) How 'pure' are they? Also: is it ...
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1answer
660 views

Why can't you see air but can feel it [closed]

Is there a device that can measure the air in the room in lbs? I would appreciate the anseer
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1answer
483 views

Percentage of a conformer in vacuum

I just started with Molecular dynamics simulations. My background is computer science but I'm learning about scientific computing and thus my jump into MD. Having said that, I was asked to calculate ...
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1answer
565 views

Quantity of Carbon and Hydrogen according to the molecular formula

$1.367$ of an organic compound containing carbon, hydrogen and oxygen was combusted in a stream of air to yield $3.002$g of $CO_2$ and $1.640$g of $H_2O$. The molecular mass of the compound was found ...
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2answers
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Approximation of electron density of a small molecule

Starting point for Quantum Theory of Atoms in Molecules (AIM) is the electron density $\rho(r)$. It could be determined experimentally (X-ray diffractions). I want to know how can we estimate them ab ...
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Polar group strong dipole effect molecular axis

There are some fundamental charactaristics of liquid crystal. One of them is that all liquid crystals are organic compounds and at one side of their long molecular foundation there exists a polar ...
3
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1answer
761 views

Number of bonds in a Lewis Structure [duplicate]

I'm asked to find the Lewis Structure of sulfuric acid, $SO_4H^-$. After struggling for a while, I sumply looked it up. How can this be? Sulfur has 6 electrons in its valence shell, so it should ...
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1answer
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How long can polyethylene molecules be?

In this video, Steve Spangler says the substance he is using (a polyethylene oxide): http://www.youtube.com/watch?v=m-88M75_PCI He mentions that one molecule would go to the moon and back twice! I ...
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1answer
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How can one find products when one knows the reagents?

I'm going to use an example (I could have used a different one); On the document it is about the study of the chemical balance of an acid-basic solution. The chemists have written the chemical ...
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0answers
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Can magnesium chloride absorb water and ammonia at the same time?

Anhydrous magnesium chloride will absorb ammonia to the tune of ($\ce{Mg(NH3)6Cl2}$). Incidentally, magnesium chloride is usually a hexahydrate ($\ce{MgCl2(H2O)6}$) at STP. My question is, could ...
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1answer
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Why do single, double and triple bonds repel each other equal amounts?

I'm here to share with you something that totally confuses me, as I can't see the logic behind it, and my teacher doesn't know either. Let's take a set of bonds that's trigonal pyramidal, with a lone ...
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What makes a molecule a polyatomic ion?

I checked the Wikipedia page, but it did not seem to provide a very intuitive explanation. What distinguishes a molecule such that it behaves like a polyatomic ion? I understand that it is a ...