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1500 questions
41
votes
2 answers
What causes the "rotting fish smell"?
Rotting fish seem to give off the same (very pungent) kind of smell, regardless of the kind (salmon, seabreen, tuna, etc).
What exactly is it that's responsible for this unique smell?
(Though I've answered my own question below, do feel free to…
paracetamol
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41
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5 answers
Why does potassium react more violently with water than lithium?
Recently, I was telling my friends about the violent reaction that takes place when you throw potassium into water. Soon after, a friend of mine claimed that lithium would react more violently than potassium.
I disagreed with him, because potassium…
Nick
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41
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2 answers
Why is arsenous acid denoted H3AsO3?
Inspired by this question, I'm wondering why arsenous acid is frequently denoted $\ce{H3AsO3}$, as opposed to $\ce{As(OH)3}$, which would appear to more accurately reflect its connectivity?
[edit]
I feel like such a doofus, forgetting about sulfuric…
Richard Terrett
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41
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5 answers
Is it safe to drink reboiled water?
There have been some claims saying that drinking reboiled water is dangerous because it produces arsenic, nitrates, etc. Is this true?
user29621
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41
votes
3 answers
Is methanol more acidic than water?
Methanol is slightly more acidic than water. Their $\mathrm{p}K_\mathrm{a}$ values, in water, are $15.5$ and $15.7$, respectively. All other aliphatic alcohols, however, are less acidic than water.
Is the following reasoning correct? This is my…
Dissenter
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41
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4 answers
Why does carbon monoxide have a greater affinity for hemoglobin than oxygen?
Hemoglobin is an iron-containing oxygen transport metalloprotein in the red blood cells of most mammals. Simply put, it's a carrier protein. Interestingly it doesn't carry carbon dioxide in the same way it does for oxygen. Oxygen binds to the iron…
bonCodigo
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41
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1 answer
Can 100% covalent bonds exist?
Every covalent bond has some ionic character and every ionic bond some covalent character. I can understand why a completely ionic bond is an ideal situation. But completely covalent bonds can exist(?).
Take the case of $\ce{H_2}$ or any other…
Gerard
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41
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3 answers
Why is the bond angle H-P-H smaller than H-N-H?
$\ce{N}$ & $\ce{P}$ are in the same group. Both $\ce{NH3}$ and $\ce{PH3}$ have one lone pair and according to VSEPR theory, both the central atoms are predicted to be $\ce{sp^3}$ hybridized.
But in spite of that, the bond angle in the former is…
user5764
41
votes
4 answers
Why can a diamond be broken using a hammer if it's the hardest natural substance known?
I've heard that diamond is the hardest natural known material but, on Google search, I found that it can easily be broken by a hammer as it's not tough.
So, what is difference between hardness and toughness? According to me, both should be the…
Harsh jain
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40
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4 answers
Five-pointed crown alkane C25H40: does it exist?
My 4 year old granddaughter, playing with molecular models, began making a cyclopentane ring, each of whose carbons bore a spiro-connected cyclopentane ring of its own , in the manner of spiro[4.4]nonane. If she hadn't run out of carbon atoms…
Charles H. Bennett
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40
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5 answers
Choosing the right condenser
What are the advantages and disadvantages of the various types of condensers commonly found in the laboratory? Obviously more intricate pieces of glassware are more costly but assuming they are all available why would one use a Dimroth condenser vs.…
Radu
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40
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2 answers
What do the prefixes meta, ortho, pyro mean in inorganic chemistry?
In inorganic chemistry, when is the prefix meta used? (as in metaborate and metasulphite)
What about the terms pyro and ortho (as in orthophosphorous acid)?
For example, I recently came to know about the prefixes per and hypo which are used to refer…
Karan Singh
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40
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3 answers
Is Hexafluorocyclohexane the "Most Polar" Small Molecule?
Earlier this year, there was a lot of attention when all-cis 1,2,3,4,5,6-hexafluorocyclohexane was synthesized*:
Notably, C&E News quoted the lead author:
This compound is remarkable for being the most polar nonionic compound now known to…
Geoff Hutchison
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40
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4 answers
DFT Functional Selection Criteria
I have a very very general question:
In DFT functional selection , mostly people speak about the most recent ones. For example my professor always asks: " which DFT Functional did you select ? " and if I say B3LYP, he says : " No ! that's too old…
Aug
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40
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Which "exotic salt" can lower water's freezing point by 70 °C?
The Medium.com article Mars Phoenix Lander, 10 Years Later shows several remarkable images and discoveries on Mars by the Mars Phoenix Lander circa 2008.
One image (shown below) shows what looks like droplets of liquid water, condensed on the…
uhoh
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