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49
votes
1 answer
Mechanism of arene side chain oxidation by permanganate
When treated with hot, concentrated acidic $\ce{KMnO4}$, arenes are oxidised to the corresponding carboxylic acids. For example, toluene is oxidised to benzoic acid.
I've tried to examine how this happens, using the mechanism of oxidation of double…
ManishEarth
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49
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1 answer
Why doesn't frozen sugar solution taste sweet?
I'll try to make this as brief as possible:
Dissolved two teaspoons of table sugar (sucrose) in about 250ml water. Sipped it, and as expected it tasted sweet. I let the rest of it sit in the freezer overnight. Next day, I took out the frozen sugar…
paracetamol
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49
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3 answers
How can I predict if a reaction will occur between any two (or more) substances?
I am new to chemistry and I find it fascinating. I am trying to learn about chemical reactions and I was wondering if there was an easy way to quickly tell if any combination of chemical substances would produce a reaction and what product(s) if any…
Ben Norris
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49
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4 answers
Why do the names of most chemical elements end with -um or -ium?
Why do the names of most chemical elements end with -um or -ium for both primordial and synthetic elements?
lambda23
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49
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5 answers
Why does bond angle decrease in the order H2O, H2S, H2Se?
I know that bond angle decreases in the order $\ce{H2O}$, $\ce{H2S}$ and $\ce{H2Se}$. I wish to know the reason for this. I think this is because of the lone pair repulsion but how?
Yomal Amarathunge
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49
votes
6 answers
Why does wood burn but not sugar?
Fundamentally, they're both carbohydrates, although the cellulose in wood is essentially polymerized glucose, which combined with its isomer fructose forms sucrose.
So why does wood readily burn while table sugar chars?
SwagMcMuffins
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48
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2 answers
What volume does one mole of an ideal gas occupy?
This has been bugging me for a while now...
Obviously, to calculate the volume/space occupied by a mole of (an ideal) gas, you'll have to specify temperature ($T$) and pressure ($P$), find the gas constant ($R$) value with the right units and plug…
paracetamol
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48
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5 answers
Fundamental forces behind covalent bonding
I understand that covalent bonding is an equilibrium state between attractive and repulsive forces, but which one of fundamental forces actually causes atoms to attract each other?
Also, am I right to think that "repulsion occurs when atoms are too…
wolfik
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48
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2 answers
Why does nitration of N,N-dimethylaniline occur at the meta position?
The nitration of N,N-dimethylaniline with $\ce{H2SO4}$ and $\ce{HNO3}$ gives mainly the meta product, even though $\ce{-NMe2}$ is an ortho,para-directing group. Why is this so?
Andrew
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48
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3 answers
What happens to a radioactive carbon dioxide molecule when its carbon-14 atom decays?
When carbon-14 decays, the decay products are nitrogen-14 and an electron (and an electron antineutrino, but that's chemically irrelevant*):
$$\ce{^14_6C -> ^14_7N + e- + \overline{v_e}}$$
Let's assume that the carbon atom in question is part of a…
Marcel
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votes
2 answers
Does oil break down condoms?
It seems that every website on sexual health advises against using oil-based lubricants with condoms. It is claimed that "oil breaks down latex". One source claimed that a latex condom completely breaks down in only 60 seconds. It made me curious,…
anon
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48
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3 answers
What is resonance, and are resonance structures real?
My teacher told me about resonance and explained it as different structures which are flipping back and forth and that we only observe a sort of average structure. How does this work? Why do the different structures not exist on their own?
bon
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48
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3 answers
Is buckminsterfullerene aromatic?
According to Wikipedia,
The $\ce{C60}$ molecule is extremely stable,[26] withstanding high temperatures and high pressures. The exposed surface of the structure can selectively react with other species while maintaining the spherical geometry.[27]…
M.A.R.
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48
votes
5 answers
Difference between thermodynamic and kinetic stability
What is the difference between thermodynamic and kinetic stability? I'd like a basic explanation, but not too simple. For example, methane does not burn until lit -- why?
Cyrus
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47
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7 answers
How can carbon dioxide be converted into carbon and oxygen?
How can $\ce{CO2}$ be converted into carbon and oxygen?
$$\ce{CO2 -> C + O2}$$
Alternatively:
$$\ce{CO2 + ? -> C + O2}$$
I'm aware that plants are capable of transforming $\ce{CO2 + H2O}$ to glucose and oxygen via photosynthesis, but I'm interested…
Wouter Dorgelo
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