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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
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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
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Why is Density Functional Theory notoriously bad at describing oxygen molecules?
I read in several papers that DFT is notoriously bad at describing free oxygen molecules but in none of them an explanation or reference concerning the problem has been provided. I guess this has something to do with its triplet ground state but I…
Philipp
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Why do rare earth metal oxides vary in color so much?
I only know a little about what causes different color, but I know it has to do with the electron orbitals and how they reflect or absorb/emit incoming light. The rare earth metals are in the lanthanide series so they all have an identical valence…
Ryan
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Which d orbitals can form sigma, pi, delta bonds?
If two $\mathrm d_{xy}$ orbitals approach each other on $x=y,$ $z=0$, would a σ bond be formed? I would think so.
Can $\mathrm d_{z^2}$ form π bond with another $\mathrm d_{z^2}?$ (As all others can on $x$ or $y$ or $z$ as internuclear axis?) I am…
Mrigank
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Oxygen or carbon with a positive charge? (comparison of canonical structures)
Which of the contributing structures of the resonance is more stable?
I'm watching a video lecture by a professor of my college where he puts this question to the class. The class unanimously says B. At first I thought they were wrong, but then…
mikhailcazi
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Why doesn't curie temperature follow a periodic trend in ferromagnetic materials
I was writing up an answer to a question which was asking why the Curie Temperature's of $\ce{Fe, Co, Ni}$ don't follow a periodic trend. The OP voluntarily deleted his question before I could finish and post my answer.
The OP has reasoned as…
getafix
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Why are halogens ortho para directing even though deactivating?
Halogens bonded to benzene ring has three lone pairs. These three electron pairs can cause resonance in benzene ring. But, halogens are also highly electronegative and thus they have strong -I effect. So, they are deactivating groups. But, why are…
Rajath Radhakrishnan
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Why can enolizable aldehydes undergo Cannizzaro reactions?
Why does 2-methylpropanal undergo a Cannizzaro reaction even though it has an $\alpha$-hydrogen?
Utkarsh Gupta
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Synthesis of mandelic acid from benzaldehyde
For an upcoming exam, I have to describe the synthesis of 2-hydroxy-2-phenylacetic acid (mandelic acid) from benzaldehyde. The provided answers describe quite a long process, consisting of 8 stages. However, I've been suggested a much simpler…
avramov
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Toxicity of metallic lead (Pb)
I have some pieces of lead ($\ce{Pb}$) at home. I keep them in a box in the closet and never touch them.
Can it be harmful?
Should I throw them away?
I would like to keep them, but I am not certain about their toxicity.
BugHunter
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How should elements be colored? And how many bonds does an atom have?
I'm working on my own 3D molecule viewer for my AP Chem class. So far everything's going together nicely. There's a couple of things I'm not sure about though...
Is there a certain rule of thumb or standard for what colors each element inside a…
Chance Leachman
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3 answers
What does it mean for meth or any other compound to be 'pure'?
In Breaking Bad, Walter White can cook $99.1\%$ pure meth. In general what does it mean for a substance to be pure? In this case, what exactly does it mean for meth to be pure? Does higher purity mean less unhealthy? More addictive? Giving more…
BCLC
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Activated Carbon - Desorption in sunlight?
I have some activated charcoal pads or small "pillows" that can be used to adsorb odors and chemical fumes from different materials.
The instructions say to put them out in sunlight to reactivate them once they have been used for a while.
What is…
Casper
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What are the products of the reaction between methanamine and nitrous acid?
What are the products of the reaction between methanamine and nitrous acid?
I'm finding this particular reaction very problematic. Here's why:
My teacher tells me that methanamine, when treated with nitrous acid (created by reacting sodium nitrite…
paracetamol
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