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2
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43 views

Would the detaching of dendrites from electrodes in a cell, result in the crystal dissolving back into the electrolyte?

Dendrites that form on the electrodes of cells shorten the cell's lifetime, and result in reduced capacity before the end of life. If the dendrites could be detached from the electrode, would they ...
9
votes
1answer
3k views

Identifying a glass frosting chemical

I have purchased an "unknown" white coloured powder from the market which can frost glass objects. Here are some properties of this powder White in colour When mixed with HCL or water, it results in ...
8
votes
3answers
343 views

Clogged drain, commercial products are ineffective

I have a clogged drain from my shower. Commercial products like Savo or WC Net totally don't work. Is there any chemical substance which can be bought without permission or which can be made easily to ...
3
votes
2answers
202 views

When considering Van der Waals forces, why do dipoles form?

Imagine two atoms, and only consider the Van der Waals force. The electron cloud will jitter due to its quantum mechanical nature- some of these jitters forming dipoles, some not. However, on average ...
6
votes
2answers
672 views

Separating NaClO from its aqueous form in bleach

I was wondering, can I separate the $\ce{NaClO}$ from the $\ce{H2O}$ in bleach. The decomposition point for $\ce{NaClO}$ is $374.14\ \mathrm{K}$, so I'm risking decomposing the compound if I do simple ...
4
votes
2answers
417 views

In orbital hybridisation, what determines the number of orbitals that hybridise to be at the same energy level?

For example, in phosphorus pentachloride five orbitals hybridize, but why not 6, as in the hydrated Al ion? I have read that the reason six orbitals hybridize is that a maximum of six oxygens can ...
2
votes
1answer
1k views

Which element is being reduced in this reaction?

Which element is reduced in this reaction: $$\ce{2KMnO_4 +3NaSO_3 +H_2O ->2MnO_2 +3NaSO_4 +2KOH}$$ I am trying to figure out which elements lose their electrons, but how am I supposed to know ...
4
votes
3answers
4k views

Why are isomers difficult to separate?

I recently learned that attempts to compare the spectra of two isomers of $\ce{C_3H_3^+}$ were frustrated by the difficulty of separating the two species. What makes these isomers difficult to ...
2
votes
1answer
225 views

Find empirical formula when individual masses are known

I'd like to illustrate my question with an example: Imagine nickel reacts with fluoride and you start with $0.766\ \mathrm{g}$ of nickel, an unknown amount of fluoride and you end with $1.261\ \...
18
votes
3answers
39k views

Bond order for carbonate ion for resonance

I saw in a textbook that for carbonate ion, there are 3 resonance forms and the bond order is 1 and 1/3. So in general, how should we calculate the bond order for resonance structures? Is there any ...
10
votes
1answer
1k views

Molecular orbitals of heteronuclear diatomic molecules

For drawing MO diagram for heteronuclear diatomic molecule, how do I know which is lower in energy than the other? For example, given a heteronuclear diatomic molecule $\ce{NO}$, which one is lower ...
1
vote
5answers
1k views

Is crushing an avocado a chemical or physical change? [duplicate]

Applying pressure can result in chemical changes, does this hold true for an avocado?
27
votes
2answers
93k views

How do non-polar substances dissolve in non-polar solvents?

The case of polar solvents is clear to me - we get an attraction between opposite charges. However, how do non-polar substances dissolve in non-polar solvents? How could it be explained on a molecular ...
7
votes
2answers
9k views

Why does 9-fluorenone dissolve in hexane?

I know like dissolves like, but I am still unclear. 9-fluorenone has a polar $\ce{C—O}$ bond. Is it because 9-fluorenone can only form London forces with other 9-fluorenone molecules and hexane can ...
4
votes
1answer
3k views

Why are noble gases stable? [duplicate]

Generally, noble gases are very unreactive. Why? I understand that it has to do with electron shielding prospective electrons that could join the atom or leave and the energies associated with both ...
10
votes
1answer
131 views

How does the work that won the 2012 Sustainable Chemistry Award contribute to sustainable chemistry?

I'm seeking a lay explanation for how the work of Dr Marc Taillefer that won the 2012 European Sustainable Chemistry Award, contributes to sustainable chemistry. From the press release, Dr. Taillefer ...
8
votes
1answer
257 views

What chemical file formats are compatible with 3D printing?

I would like to print some molecules rather than building them using a kit. What file formats work?
4
votes
1answer
203 views

Calculating laser wavelength/power to cause emission of light in a gas?

It's been a long, long time since I've had to worry about electron excitation levels and band gaps. Please forgive (and correct!) my terminology and misconceptions. I've become interested in ...
10
votes
2answers
3k views

Calculating entropy: why consider a reversible path?

I am reading up on entropy in a textbook and I got confused by this: It says that to calculate the entropy for an irreversible process using heat flow, one must imagine the reversible process in ...
7
votes
1answer
170 views

Are redox half-reactions “real”?

Are the half-reactions used in analyzing redox reactions a real thing or are they a conceptual shortcut? Is there a way to, however briefly, run a half-reaction by itself without the corresponding ...
7
votes
2answers
258 views

Is it possible to get energy from frozen methane without oxygen?

In one of the solar system documentaries it was mentioned there are moons in the solar system with lakes of frozen methane. Assuming humans or robots or whatever could make it there, would there be a ...
3
votes
1answer
616 views

Are there any nonflammable thermal insulators which can be made at home?

I am trying to build a homemade thermos. It needs to be able to conserve the heat in 125 ml of water for 15 minutes. However, unlike a normal thermos, it also needs to be able to be heated. What ...
5
votes
1answer
1k views

Using Dalton's law of partial pressures

A container of volume $\pu{4.0 L}$ contains nitrogen at $\pu{25 °C}$ and $\pu{803 kPa}.$ This container is connected by a valve to another container of volume $\pu{10.0 L}$ that contains argon at $\pu{...
0
votes
1answer
2k views

Specific heat capacity and the periodic table

Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium ) The question I have encountered is as follows: ...
9
votes
1answer
131 views

Materials used in metallic glass

I've been looking over the lists of materials used together to make metallic glass. Is it purely coincidental that if you round up/down any decimals from the atomic weight of elements used to ...
3
votes
2answers
609 views

What's the name of this electrolysis device?

I've seen it in a couple of videos, it's used to electrolyze water in 2 different containers at the same time to make a comparison and thus is very handy. What is it called (besides just a ...
20
votes
3answers
5k views

What are the chemical reactions behind fire?

I've always wondered what the chemistry behind fire is. What are the basic chemical reactions behind a simple wood fire, and how do they manifest into this phenomenon?
8
votes
2answers
4k views

Which species dissociate completely in ionic equations?

I am tasked with writing a molecular equation, an overall ionic equation, and a net ionic equation for the reaction between an aqueous solution of phosphoric acid, $\ce{H3PO4{(aq)}}$ and an aqueous ...
8
votes
2answers
677 views

Proper IUPAC name of a substituted cyclohexenol

Here's the molecule: So far I've tried: 6-methylcyclohex-2-en-ol and 4-methylcyclohexen-3-ol but both are wrong. I'm rather confused as to where I should start: the alcohol or the double bond?
4
votes
1answer
5k views

Is there a way to detect bleach residue on a surface?

I was wondering if there is a way to detect for presence or residue of bleach using household items. I am curious about either chlorine-based or peroxide-based. It can be any sort of reaction that ...
-1
votes
2answers
4k views

How does Phosphorus Pentachloride bond?

The thing I am having trouble with: why does $\small\ce{PCl4}$ form a +1 ion and $\small\ce{Cl}$ a -1 ion?
2
votes
1answer
157 views

How are crystals formed from a gas?

In crystallization, crystals are formed from liquids by cooling. How can crystals be formed from a gas by cooling?
6
votes
1answer
18k views

Is there a way to calculate how fast water will cool?

Is there a way to calculate how fast water will cool if you know the water's starting temperature and temperature of the environment that you put it in, such as a freezer?
4
votes
1answer
56k views

Order of elements in a formula? [duplicate]

Possible Duplicate: Why is methane's molecular formula conventionally “CH4”, while water is “H20” (among others)? If I have a formula containing 4 hydrogen atoms and 1 ...
9
votes
3answers
9k views

Chemical reactions with a room-scale cooling effect

Are there chemical reactions that could cool down an average sized room by a noticeable amount (say 5 °C)? I would like to investigate if it is possible to have a situation where I can mix 2 ...
1
vote
2answers
134 views

Should the anode potential be increased or decreased to generate current?

I am taking a course on fuel cells and we were talking about the activation energy needed to start a chemical reaction. I would think that the answer to this question is that the anode potential ...
3
votes
1answer
3k views

What is the electron dot structure of an alkyne? [closed]

I am trying to determine the electron dot structure of an alkyne like $\ce{C2H2}$. I know that hydrocarbons with at least one carbon-carbon triple bond are called alkynes, and their general formula ...
5
votes
1answer
438 views

Shape of C₂H₂ molecule

What is the shape of the $\ce{C2H2}$ molecule? The fact that is has a triple covalent bond between the 2 carbon atoms and 2 other bonding pairs between the hydrogen and carbon atoms leads me to ...
4
votes
2answers
10k views

Boiling point of vodka

What is the boiling point of vodka? I have found the boiling point of ethanol, ~173 (degrees) F. However, I am unable to find the boiling point of vodka. I found some information on it, but I do not ...
9
votes
1answer
3k views

Options for long term storage of helium?

Specifically, if I wanted to purchase a large amounts of helium, what are my options for purchasing helium in a state that is suitable for long term storage? It's my understanding that if I were to ...
13
votes
1answer
385 views

The Evans auxiliary: rotational freedom of the benzyl group - stereoselectivity still guaranteed?

I created the L-Phenylalanine based Evans auxiliary bearing a benzyl group with help of a molecular model set and got into some questions. The structural formula will do: As I suppose a low ...
4
votes
1answer
2k views

How do I balance the combustion reaction of butene?

I have butene being burned in a fuel rich engine and I can't seem to balance this reaction: $$\ce{C4H8 + $a$(O2 + 3.76 N2) -> $b$ CO2 + $c$ H2O + $d$ C4H8 + $e$ (3.76 N2)}$$ When I try write ...
3
votes
1answer
983 views

Understanding the rate of change in titration curves

As I am looking at titration curves, a few things stand out. For now, I have a two part question: When titrating an acid with a base, for instance, the pH rises more or less abruptly around the ...
1
vote
2answers
613 views

Can caffeine be separated from coffee?

Is there a way to extract caffeine from coffee completely?
7
votes
3answers
3k views

Why does polonium form acidic oxides?

All metals form basic oxides. Metallic oxides are basic in character. Polonium is a metal, so it should form basic oxides but it forms acidic oxides. Why are its oxides acidic in character?
4
votes
1answer
414 views

How does hot tub “shock” work?

Hot tub shock is potassium peroxymonosulfate. When added to a hot tub, it creates bubbles. It is said to oxidize organic debris in the water. What is the reaction?
4
votes
1answer
287 views

Is ash fireproof?

At high temperatures (almost) everything burns to ash. Is ash 'fireproof'? Is further combustion of ash possible for example by combining with hydrogen, oxygen, etc?
5
votes
1answer
246 views

Why not “Oxygate” OO4(2-)?

So many atoms can be surrounded by oxygen atoms to make anions - chromate, phosphate, etc. In particular there's Tellurate $\ce{TeO4^{-2}}$, Selenate $\ce{SeO4^{-2}}$ and Sulfate $\ce{SO4^{-2}}$ - ...
5
votes
2answers
279 views

Energy of the n-th level for an atom

Going through the Bohr's model and his assumptions, I came across with this formula to find the energy of the n-th level of any atom: $$E = - \frac{Z k_e e^2}{2r_n} = -\frac{Z^2(k_e e^2)^2m_e}{2\...
9
votes
1answer
10k views

How is the yellow colour of nitric acid removed?

Nitric acid obtained in laboratory is slightly yellow due to the dissolution of nitrogen dioxide which is produced due to thermal decomposition of a portion of $\ce{HNO3}$. $$ \ce {4HNO3 -> 2H2O ...

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