Most Popular
1500 questions
14
votes
1 answer
What determines whether a step in a reaction is reversible?
What makes a step in a reaction not reversible? I'm learning all these mechanisms and having to memorize which steps are reversible. Is there a way to figure out whether it's reversible or not?
user34748
- 371
- 2
- 9
14
votes
2 answers
Can drinking a lot of water be fatal?
I vaguely recall having heard that drinking too much water can, over time, prove fatal to the human body.
Nothing special about the water; not distilled or de-ionized or anything … just plain ol' water.
Now the reason that accompanied this "fact",…
paracetamol
- 18,297
- 26
- 102
- 166
14
votes
1 answer
Can diamond undergo a self sustaining combustion reaction all the way to carbon dioxide?
I know charcoal can smoulder in an incomplete combustion to produce carbon monoxide so I assume diamond also can. If it's heated to a sufficiently high temperature, will the reaction produce enough heat to sustain the full combustion reaction all…
Timothy
- 468
- 3
- 13
14
votes
1 answer
Help with derivation on why antibonding orbitals are more antibonding
I have read How can antibonding orbitals be more antibonding than bonding orbitals are bonding?. But I am intersted in a specific derivation. During lecture my professor stated that the overlap $S_{ij}$ integral can be between -1 and 1. In other…
CoffeeIsLife
- 4,236
- 1
- 20
- 49
14
votes
1 answer
Dipole-quadrupole polarizability term for induced dipole
For describing an induced dipole, I have usually seen the following equation,
$$
P_{i} = \alpha_{ij}E_{j} + \frac{1}{2}\beta_{ijk}E_{j}E_{k}
$$
where $P_{i}$ is the $i^{\text{th}}$ component of the induced dipole moment, $\alpha$ is the (dipole)…
ankit7540
- 1,562
- 8
- 20
14
votes
1 answer
How to make Poinsettia pigment into ink?
Like many families, this winter we had bought a red poinsettia plant to decorate our kitchen, and now that it's losing its leaves, I had the genius idea to extract the red pigment. The activity proved a success, and let my 5 yr baby girl amazed (and…
Adrian Man
- 143
- 4
14
votes
2 answers
How can aluminium oxide be called an acid?
Aluminium oxide is amphoteric. It is easy to see that it is a Brønsted-Lowry base through the following reaction:
$$\ce{Al_2O_3 + 6HCl \rightarrow 2AlCl_3 + 3H_2O}$$
The aluminum oxide splits and the oxygen accepts a proton, forming water.
But what…
Gerard
- 3,383
- 13
- 37
- 49
14
votes
6 answers
Handling and storing sodium hydroxide, hydrochloric acid, hydrogen peroxide and isopropyl alcohol
I'm an electrical engineering and I hope you can give me some advice as I'm not much into chemistry.
I'm trying to start making my PCB (Printed Circuit Board) at home but I'd like to have some advice concerning how to handle and where to store these…
user51166
- 457
- 3
- 5
- 9
14
votes
1 answer
Why are the total energies of transition states so commonly corrected for zero-point vibrational energy?
So often I see total energies of transition states corrected for zero-point vibrational energy which always confuses me. Zero point energy is the lowest energy that a ground state minimum energy configuration can have at 0K in a vacuum. Transition…
LordStryker
- 4,589
- 1
- 39
- 61
14
votes
1 answer
What are the practical differences between the various DMSO oxidations (Swern, etc.)?
Recently, I was reading a paper about a total synthesis of (+)-rubriflordilactone A (the article is open access: Angew. Chem. Int. Ed. 2015, 54 (43), 12618–12621). In two different steps where an alcohol -> aldehyde oxidation was required, the…
orthocresol
- 69,151
- 11
- 230
- 391
14
votes
3 answers
Why can't a reaction go to completion?
What is the reason for why an exergonic reaction would still have some remaining reactants (or an endergonic reaction to have any products)? The explanation given on this page (see Chemical reactions and mixing) is that there is a Gibbs free energy…
Yunfei Ma
- 1,562
- 3
- 17
- 30
14
votes
2 answers
Configuration of chiral center in cocaine
I couldn't get the absolute configuration for the chiral center I marked. I got R, but according to my answer key it is apparently S. Would really appreciate an explanation.
cynthia
- 149
- 1
- 3
14
votes
2 answers
Why is isoindole unstable?
According to this paper, isoindole is unstable because the 1-carbon in the isoindolidine tautomer is very electron-deficient. I figured that the electron-deficiency of this carbon must be because it is bonded to an aromatic carbon and double bonded…
Joshua Meyers
- 329
- 1
- 8
14
votes
1 answer
Aurora borealis - less favored energy transitions higher in atmosphere?
This question describes how some energy transitions become more prominent as you higher in the atmosphere. Short summary: Some electron transitions are "forbidden" by quantum mechanical selection rules, and so have a larger time delay from time of…
Adroit
- 770
- 3
- 21
14
votes
2 answers
What exactly is a spontaneous reaction?
What I understand by a spontaneous reaction is that - A reaction whose G is negative and which occurs without the input of energy.
Gasoline reacts with oxygen only if a spark is provided. So how can it be a spontaneous reaction?
Do nonspontaneous…
biogirl
- 1,360
- 7
- 18
- 34