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 ...

learn more… | top users | synonyms

2
votes
1answer
25 views

Calculating the number of molecules remaining

This is the question in my text book: From $392\:\mathrm{mg}$ of $\ce{H2SO4}$, $1.204 \times 10^{21}$ molecules are removed. How many moles of $\ce{H2SO4}$ are left? What I tried doing: First I ...
6
votes
4answers
456 views

Why is CF4 non-polar and CHF3 polar?

This question is a bit tricky to me because of the following: Take in consideration these two molecules: $\ce{CHF3}$ and $\ce{CF4}$ These are their Lewis dot structure: $\ce{CHF3}$ $\ce{CF4}$ ...
9
votes
2answers
305 views

How long do the bonds in a molecule hold under nominally stable conditions?

Disclaimer: I am not a chemist I was just drinking my Ice Age mineral water which is 'untouched since the Ice Age' and wondered if the bonds formed in each molecule have remained intact for all those ...
7
votes
1answer
517 views

Really how rare are hydrogen atoms?

Hasok Chang, a chemist, but perhaps more a philosopher recently published the book Is Water H2O? . Chang used the question and an extensive web of arguments ultimately as a platform to support a ...
3
votes
1answer
35 views

What causes “stringy” melted cheese (and similar behavior in other materials)?

I was wondering about this. What is the physics underlying the "stringy" consistency of melted cheese? That is, when the melted cheese is hot, and it is pulled apart, it forms strings of cheese. This ...
1
vote
1answer
44 views

Equivalent hydrogens in 2,3-dimethylbutane

So while calculating for the relative yield of monochlorination for 2,3-dimethylbutane, I was counting the primary hydrogens, I counted 6, but in fact it was 12. Why is it 12? How do you find ...
2
votes
1answer
35 views

MO for $N_2^{2-}$

Could someone please show me the MO diagram for $\ce{N_2^{2-}}$? What I did was since N has 5 valence $\ce{e^{-}}$, then $\ce{N_2}$ must have 10, and $\ce{N_2^{2-}}$ must have 12. And $\ce{N}$ has $s$ ...
1
vote
0answers
14 views

What radius best represents reaction distance?

Molecules must be within a certain distance for a reaction to begin as well as satisfying a myriad of other factors. Whilst the exact distance varies from reaction to reaction, is their any ...
4
votes
2answers
25 views

Interaction radius of a molecule

What is the most commonly used radius of an atom or molecule to describe the area that must touch another area of another molecule for the two to react. Is there one radius that always works or does ...
2
votes
1answer
83 views

Why might two different chemical structures smell the same?

From what I understand, it is the functional group attached to a structure that determines the odor it will give off, for the most part. Which explains why two similar molecules, except for their ...
8
votes
2answers
65 views

What causes spray cans to get cooler when shaken?

I've been searching the web for this phenomenon and surprisingly I found only one post about it. And the reply to this question about canned air begins with words: I don't know about the shaking ...
9
votes
3answers
365 views

Explain the formation of replicators to a layman

I am reading The Selfish Gene by Richard Dawkins. I am on chapter two. He speaks of the observation of the formation of amino-acids when you simulate environmental conditions of primordial ...
0
votes
0answers
58 views

Diatomic Molecules/Elements

What is the difference between diatomic molecules and elements? Also, If oxygen is element of a single atom, then what makes it a diatomic element? But, then I read that a single oxygen atom can ...
3
votes
1answer
33 views

Amount of substance of a molecule in a solute the same as amount of substance of constituent elements?

I’ve done absolutely no chemistry since high school. Now, 16 years later, I’ve been asked to look at some chemical analyses and I’m having trouble! Context: I’ve got a series of spectroscopy ...
1
vote
0answers
34 views

Chirality vs Resonance in chemical structure

In a reference book, chirality of a molecule is explained as "handedness", like our right and left hand, which are mirror images of each other. These are also called as enantiomers. The nearest clue ...
1
vote
0answers
13 views

What is the mean curvature of nitrates and nitrites?

I am reading the book Soft Matter Physics - Synthetic and Biological Self-Assembling Materials from Hamley and particularly page 201. I started to think how this packing occurs in case of molecules ...
1
vote
1answer
85 views

Is this a possible explanation as to why sigma bonds are stronger than pi bonds?

Sigma bonds form due to the axial overlap of two orbitals whereas pi bonds form due to their lateral overlapping. Since the former is more effective, we can say that sigma is stronger than pi. We mean ...
3
votes
1answer
20 views

How exactly do alcohol molecules dissolve in seawater?

The book "Lehrbuch der anorganischen Chemie" by Arnold F. Hollemann on page 47[link here][1] states that dropping 0.8g Alcohol (M = 46g/mol) in a sea or ocean would result in every litre seawater ...
2
votes
2answers
37 views

Does Uranium ore count as a mixture?

I'm doing an assignment where we must research the separation of a mixture to obtain a useful final product. I thought about the separation of Uranium from its ore after it has been mined, but I did ...
2
votes
0answers
47 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
119 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
vote
1answer
38 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 ...
-4
votes
1answer
88 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
65 views

On the molecular level, how do catalysts work? [closed]

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
votes
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
70 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
47 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
74 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
130 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
51 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 ...
2
votes
0answers
52 views

First ionization energy of hydrogen molecule

If we have the dissociation's energies of hydrogen molecule $\ce{H_{2}}$($D_{0}$) and the corresponding molecule ion $\ce{H_{2}^{+}}$ ($D_{1}$) together with the first energy of ionization of hydrogen ...
0
votes
0answers
54 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
91 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
428 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
849 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
1k 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
471 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
101 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
797 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
138 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
89 views

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

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 ...
2
votes
1answer
27 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
1k 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
votes
0answers
48 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
94 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 ?
3
votes
2answers
36 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?
6
votes
1answer
4k views

What holds atoms together?

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? How are molecules of ...
-2
votes
1answer
60 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
268 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 ...