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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Calculate the percentage of sulfur and oxygen in: sulfur dioxide & sulfur trioxide

It says to divide the mass of the sulfur by the mass of the compound, but I'm having trouble trying to figure out how to find the mass of the compound.
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34 views

Compound empirical exercise

A compound has $67.3 \% \rm~C,4.62 \%~N,6.93 \%~ H$ and O. Determine the molecular formula of the compound knowing its molar mass is $283\rm~\frac{g}{mol}$. My solution : The percentage for the ...
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1answer
40 views

Can you create artificial molecules with a machine?

Is it possible to create molecules with machines? For example: you shoot one Oxygen-atom (O) on one diatomic Hydrogen ($\ce{H2}$) to create one water molecule ($\ce{H2O}$).
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1answer
50 views

Stability of CN molecule

The CN molecule has been observed spectroscopically in comets where pressure has been estimated to be as low as $10^{-10}$ mm Hg. Draw a Lewis structure for CN. Suggest an explanation as to why this ...
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0answers
26 views

DNA sub modules

In a large polymer molecule (such as a DNA chain) which is made from multiple component monomers containing many atoms, how was it determined that the chain was made up from the four groups of ...
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1answer
34 views

In which cases do you say “oxide” when naming a molecule?

Based on the names of following molecules I got quite confused about the correct nomenclature: $\ce{NaHCO3}$ $\ce{K2SiO3}$ $\ce{PbCrO4}$ In none of the above molecule names you ever say "oxide" ...
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3answers
532 views

Is there a way to use free software to convert SMILES strings to structures?

So far I've been unsuccessful in finding an open source tool that will convert a large number (>100k) of SMILES strings to a chemical structure. Is this really only solved by commercial applications? ...
4
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1answer
303 views

Why is NO2 formed when N valency is 3

Sorry if the question is silly but this is troubling me more than enough. Here's what I know about chemical formula: Reverse the valencies of the combining elements. But in this case, $\ce{NO2}$ is ...
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2answers
73 views

Shouldn't all of group 16 form double bonds? [duplicate]

I notice that out of all of group 16 oxygen is the only element that can form a double bond. Why is that because shouldn't all of group 16 be able to form a double bond and be diatomic because they ...
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1answer
30 views

Can $\ce{CO_2}$ be separated into $\ce{C}$ and $\ce{O_2}$? [duplicate]

I am a grade 8 student and I need to do some background research for a science project of our choice, and my project relies on if $\ce{CO_2}$ can be separated into a $\ce{C}$ and $\ce{O_2}$. So, Is ...
3
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1answer
56 views

How is a side-group that contains a double bond named?

In my chemistry lecture, we are working on the naming and nomenclature of organic molecules. When we got to the naming of alkenes and alkynes, we were told that the functional group had to be in the ...
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1answer
38 views

Are the collisions between the real gas particles perfectly elastic?

Well my question is simple, if two real gas particles are colliding (head on collision) then will the kinetic energy will be conserved i.e. will it be a perfectly elastic collisions?
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2answers
56 views

Is this graphic of molecules correct?

First off, huge fan of chemistry, not a chemist – do be nice :D Would an image like this make sense as an infographic for the molecular composition of the air? I especially wonder if the different ...
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1answer
45 views

What would carbon-oxygen polymer be called?

So I have a chain molecule made of carbon and oxygen, and I'm not sure what it would be called. Would any of you lovely fellows be able to help me? The best name I've been able to come up with so ...
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0answers
39 views

Can one component of a mixture penetrate the skin if the whole mixture cannot?

There's a general rule that says that compounds under 500 dalton are able to penetrate the skin without any special vehicle (such as ethanol). I've started using castor oil, which contains different ...
14
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1answer
207 views

Symmetrize nearly symmetric molecule

In the overall good paper of Beruski et. al.,[1] an algorithm of how to symmetrize an "almost symmetric" molecule by symmetrizing the distance matrix is given for the example of Methane. The ...
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2answers
38 views

Is water a heterogeneous molecule? [closed]

My question is based upon the statement found here: an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium ...
0
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1answer
41 views

Which of the following samples is impossible? [closed]

Given the following atomic masses: Aw(Al) = 26.98 amu Aw(O) = 16.00 amu Aw(C) = 12.01 amu Aw(H) = 1.00 amu Aw(Fe) = 55.85 amu I'm trying to determine which of the following doesn't make sense, ...
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1answer
120 views

Structure diagrams indicate plausible structures? [closed]

Structure diagrams have a hexagonal, "chicken wire" shape, which leads to more elegant representations of some molecules than others. For example, the following diagram must deviate from the usual ...
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3answers
78 views

Teaching: Two elements that make XY2 and XY4 molecules

I am not a chemist, but I will be explaining chemistry to some third-graders. I want to give the example of how different things can be made of the same parts, but arranged differently. My "real ...
2
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1answer
168 views

Why is Iodine's melting point is lower than water?

My teacher told us that melting point of Iodine is lower than Ice as it is a Simple molecular structure bonded by weak van der waals forces. However I gooogle and found out its melting point is ...
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0answers
50 views

positions of a methane molecule with carbon atom at the origin [closed]

Let $\text{CH}_4$ be the molecule of Methane: The four hydrogen atoms form vertices of a regular tetrahedron with the carbon atom in the center of the regular tetrahedron. Here we regard all atoms ...
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2answers
3k views

What is the difference between “molecular mass”, “average atomic mass” and “molar mass”?

I don't understand the difference between "molecular mass" and "average atomic mass". They seem like the same thing to me. Is it that average atomic mass is just the weighted average of the ...
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1answer
90 views

Molarity of Sodium Ion Concentration (and some really weird answers…)

I know how to do this problem really easily but I don't know why my answer is wrong... The problem is: What is the molarity of sodium ions in a solution prepared by diluting $250\ \text{mL}$ of ...
3
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1answer
133 views

Is there any molecule visualizing software for Python?

I am looking for a free and open-source software written or wrapped for Python that would simply allow me to generate bunch of figures (in eps, jpg, or pdf format) from a set of xyz files, e.g. water ...
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1answer
57 views

Molecules aren't the same as atoms?

Question is simple but tricky, for example my chemistry teacher says that preservatives on food for example Nitrate N3 are not good in excess for your body (like everything else), but if Nitrogen is ...
3
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1answer
84 views

If you can smell something does that mean that this thing loses molecules?

When you can smell something there must be some molecules in your nose which signalize the smell in your nose. Does that mean, that e.g. a cheese is losing molecules which fly into your nose? And does ...
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1answer
44 views

Good measures ot atomic size

I was looking up the Lennard-Jones parameter $\sigma$ (which, to my understanding, is a measure of molecular size) when I was surprised to discover that the value for the $\ce{N2}$ molecule (3.667 Å) ...
15
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1answer
771 views

Are long Oxygen molecules possible?

Are large oxygen containing molecules possible? Either large rings, or chains with hydrogen atoms at the ends. Like this: $\ce{H-O-O-O-O-O-O-O-O-O-... -O-O-O-O-O-H}$
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1answer
64 views

At what point does Avogadro's law not apply?

A mole of hydrogen gas takes up 22.4 L, but so does a larger molecule like $\ce{CO2}$. Methane ($\ce{CH4}$) is an even larger sized molecule, but a mole of it will still take up 22.4 L. I would assume ...
2
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1answer
87 views

Molecules made of molecules?

When a molecule of water ($\ce{H2O}$) and a molecule of hydrochloric acid ($\ce{HCl}$) react together, would they become a molecule made of molecules? What's the name for such thing? How would it be ...
8
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1answer
147 views

What makes water a liquid (when it is)?

I'm curious about what the minimal conditions for some collection of water molecules to be liquid water are. What is the minimum number? What sort of bonds must hold? What other sorts of things I ...
6
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1answer
1k views

Why does SO2 have a larger bond angle than H2O, H2S, and NH3

So we have to find which of the follwing compounds has the smallest bond angle: $\ce{H2O}$, $\ce{H2S}$, $\ce{NH3}$, $\ce{SO2}$. So L $\propto \frac{1}{BA}$ where $L$ is the number of lone pairs and ...
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1answer
78 views

Identifying the number of bonding and lone pairs without a dot and cross diagram

I've just learned how to predict the shapes of molecules in class today using VSEPR theory. I would like to ask is there anyway to find the number of bond pairs and lone pairs without drawing a ...
4
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1answer
147 views

How does molecular collision excites the electron?

I have this question for a long time that in LASER when we do the pumping by heating how does molecular collision causes the atoms(molecules) to reach in excited state. E.g. in $\ce{He-Ne}$ laser when ...
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1answer
62 views

Find oxidation number of a metal in a compound

Calculate the oxidation number of $\ce{Fe}$ in $\ce{Fe2O3}$. Alright. So we have a metal and an non metal. This means that iron will lose electrons and give them to oxygen. So it will be a ...
3
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0answers
43 views

How can I tell if a molecule is polar or not? [duplicate]

Consider $$\ce{PCl3}\\ \ce{CH2Cl2}\\ \ce{HCN}\\ \ce{SiO2}$$ Which ones are polar substances? I appear to be lacking on the concept of "polar substance". I was just studying about Lewis ...
3
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0answers
160 views

What makes a compound a dehydrating agent?

When a carboxylic acid with low molecular weight is heated with $\ce{P2O5}$ we get the corresponding anhydride. My book says that this reaction happens with dehydrating agents such as $\ce{P2O5}$. I ...
5
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1answer
163 views

Can molten sugar also rotate polarized light as sugar water does?

It is well know that the sugar water can rotate the plane of linearly polarized light, so light bends when travelling in sugar water. However, do the liquid state of sugar but not the sugar solution ...
3
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1answer
109 views

Empirical and molecular formula

I was doing a homework assignment and I got the following question wrong because I was supposed to multiply the empirical formula by 3 to get the molecular formula of $\ce{C6H10S2O}$. I put ...
4
votes
1answer
65 views

Reaction of Silicon monoxide with alcohols

Elements from the carbon group tend to form compounds with two oxygen's. Let's say I want to produce $\ce{SiO_2}$ out of $\ce{SiO}$ by mixing it with some alcohol, for example: $$\ce{SiO + ...
6
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1answer
139 views

Only-C chain molecules

Are (cyclic) $\ce{C}$-chain molecules as in the picture likely to occur or do they exist at all? and so on... EDIT: I'm considering only double bonds between $\ce{C}$ atoms. This rules out most ...
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0answers
40 views

Why are H2O asymmetric while CO2 is not? [duplicate]

What is the reason for water molecules $\ce{H_2O}$ being asymmetric while other molecules like $\ce{CO_2}$ being completely symmetric? See the pictures below: In both case there is an ...
3
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2answers
104 views

Are all molecular structures symmetric?

Are all molecular structure symmetric either in relation to a plane within itself or in relation to other molecules? Are there any completely asymmetrical structures when looking at molecular ...
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0answers
48 views

Method of representing molecules as 3d objects with surfaces [closed]

I need a way of representing molecules in 3d form. I wish to be able to define a 3d surface for simple organic molecules. Can anyone advise me on this? Are there any approaches, or solutions to this ...
7
votes
1answer
1k views

Which relatively simple molecules violate the octet rule?

I'm learning how to draw Lewis diagrams. Everything I've read emphasizes the octet rule. However, to the best of my knowledge, that rule only applies to elements in the first three periods. On our ...
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1answer
44 views

Which one of the following has less probability to create multiple bonds : N, P, C, S, Al, Ba? [closed]

Which one of the following has less probability to create multiple bonds? Phosphorus , Nitrogen, Aluminum, Sulfur, Carbon, Barium How can I know that from the Periodic Table? is there a certain ...
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0answers
39 views

Sugar dissolution test

Is there a way to detect whether sugar is completely dissolved in a cup of water other than looking at the bottom of the cup? I was wondering if there is a test or something that can be carried out ...
7
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1answer
133 views

What does the 129Xe NMR spectrum of XeOF4 look like?

What will the $\ce{^129Xe}$ NMR spectrum of $\ce{XeOF4}$ look like? I know that its electron pair geometry is octahedral, and the molecular pair geometry is square pyramidal. I believe that the ...
3
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2answers
183 views

Are these 3 molecular structures of ammonium bicarbonate the same?

Are these 3 molecular structures of ammonium bicarbonate the same? A: B: C: