Unanswered Questions
516 questions with no upvoted or accepted answers
13
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1
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7k
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Why do alpha-hydroxy ketones respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests?
I learnt from a certain textbook that aldehydes and formic acid respond positively to Tollens', Fehling's, Benedict's, Schiff's and HgCl2 tests.
However, in another textbook I read that even alpha-...
- 1
10
votes
0
answers
20k
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Why does the reaction of sodium nitrate, aluminium, and sodium hydroxide yield ammonia?
From Russian test problem 4301:
$$\ce{3NaNO3 + 8Al + 5NaOH + 18H2O -> 8Na[Al(OH)4] + 3NH3(g)}$$
How does ammonia evolve here? Is it that we get hydrogen gas evolving in the reaction between Al and ...
- 6,801
8
votes
0
answers
392
views
What exactly is an "electron-sponge"?
What exactly an "electron-sponge" [behavior/action/property/system] nickname is, and what makes a material an "electron-sponge" (preferably, quantitatively)?
From what I found, it's typically a ...
- 38.4k
6
votes
0
answers
451
views
How to explain oxidizing power from Molecular Orbital Theory
I am trying to explain the oxidizing property of $\ce{Fe^3+}$ in $\ce{H2O}$ and $\ce{CN^-}$ which is $\ce{[Fe(H2O)6]^3+}$ and $\ce{[Fe(CN)6]^3-}$.
The electrochemical reactions along with their ...
CommunityBot
- 1
6
votes
0
answers
164
views
Why is supersaturated sodium acetate so (meta)stable?
Sodium acetate is a common example used in general chemistry lectures to illustrate the idea of supersaturation, and that precipitation of a supersaturated solution can be initiated by a seed crystal. ...
- 71.6k
6
votes
0
answers
775
views
How can copper(II) sulfate crystallize outside a glass vial?
I'm making copper sulfate crystals in glasses. Within a few weeks, the copper sulfate seems to crystallize both inside and outside the glass:
(A few weeks after making a new solution)
(Yet another ...
- 17.5k
6
votes
0
answers
2k
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Finding theoretical mechanism of sodium thiosulphate and hydrochloric acid
In class we conducted an experiment where we timed reactions between sodium thiosulphate and hydrochloric acid. We kept the concentration of the $\ce{HCl}$ constant, while changing the concentrations ...
- 71.6k
6
votes
0
answers
15k
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How to determine the iron content in spinach from a titration with permanganate solution?
I used titration to find the mass of iron in a $5~\mathrm{g}$ sample of spinach after leaving the spinach to soak in tap water for five different lengths of times. I added $\ce{H2SO4}$ to the solution ...
- 6,801
6
votes
0
answers
373
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Lemieux-Johnson oxidation on cycles
Consider 5-cyano-2,2-dimethylpentyl 4-methylbenzene-1-sulfonate:
What would it yield by a Lemieux-Johonson oxydation ($\ce{OsO4}$, $\ce{NaIO4}$)?
My first guess would have been that $\ce{OsO4}$ was ...
- 44.3k
5
votes
0
answers
78
views
Does catechol give Tollens’ test?
Do hydroquinones like catechol or p-hydroxyphenol give Tollens’ test?
I know that β-diketones can reduce Tollens’ reagent to give a “silver mirror”, so I would guess that due to tautomerization ...
- 38.4k
5
votes
0
answers
123
views
Regarding the standard reduction potential and electrolyte/solid interface
I am modelling lithium-sulfur batteries ($\ce{LiS}$ batteries) and a strange phenomenom happens during charge, named infinite charging, which I show below:
The factor $f_\mathrm{C}$ that appears in ...
- 3,669
5
votes
0
answers
81
views
Oxygen tolerant RAFT polymerization using AIBN?
I want to do some RAFT polymerizations but don't have a nitrogen line at the moment. It seems that people have recently implemented oxygen scavenging strategies to enable open-air RAFT polymerization. ...
- 30.4k
5
votes
0
answers
121
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Will charcoal (carbon) oxidize in the air?
Wikipedia — Carbon sequestration claims that burying charcoal into the soil offsets $\ce{CO2}$ and thus reduces the greenhouse effect:
In the soil, the biochar carbon is unavailable for oxidation to $...
- 38.4k
5
votes
0
answers
187
views
What pH value of 1M sodium crotonate solution supposed to be?
I need to prepare the $\pu{1M}$ solution of sodium crotonate, however, I don't have one in lab, but I do have sodium hydroxide and crotonic acid.
Thus, I calculated that for $\pu{100 mL}$ of $\pu{1M}$ ...
- 151
5
votes
0
answers
793
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Solubility of PbSO4
The solubility of $\ce{PbSO4(s)}$ increase with the addition of $\ce{H2SO4}.$ Why?
I don't quite understand this. When dissolving $\ce{PbSO4(s)}$ we get the equilibrium equation:
$$\ce{PbSO4(s) <=...
- 38.4k