7
votes
1answer
52 views

How is spiro[4.4]nonatetraene antiaromatic

How is spiro[4.4]nonatetraene antiaromatic? I know that spiro compounds exhibit homoaromaticity, but how do they exhibit antiaromaticity?
0
votes
0answers
22 views

nail polish remover WITHOUT ACETONE and My poor Laptop

today i was trying to clean my Poor Laptop with a nail polish remover. Not only it didn't get clean but some white thing remained on the keys. I tried boiling water and a piece of cloth to make it ...
3
votes
0answers
14 views

Water/ethanol mixing problem

In the following question, the water/wine mixing problem was recast in chemical terms. However, partial molar volumes can make this a much more challenging problem than it appears on the surface. ...
-2
votes
0answers
14 views

Molar heat of combustion question

The molar heat of combustion of ethanol is 1367 kJ/mol. What mass of ethanol must be combusted to raise the temperature of 0.250 kg of water from 20 °C to 60 °C? I know $\Delta H = mc \Delta T$. I’m ...
-2
votes
0answers
21 views

How do you balance very complicated chemical equations? [on hold]

For example, I was trying to balance the chemical reaction of a complete propanol combustion, and found it difficult to. Is there a systematic way?
0
votes
0answers
13 views

R32 Space Group

Which are the elements of the Twofold Screw Axis in this image? The "+" and "-" elements that intercept the red line are the elements of the Twofold Screw Axis 2/3? And if so, is the height of the ...
1
vote
1answer
27 views

How many electrons can have the quantum number set n=5, l=3, ml=-1? [on hold]

How many electrons can have the quantum number set $n=6,\ l=3,\ m_l=-1$? Also, please explain why. I know that n describes the number of shells in an atom but what do n, l, and ml have to do with ...
3
votes
1answer
28 views

Boiling/melting points of cyclohexane and cycloheptane

I’m looking at a chart in my book, and while cycloheptane has a higher boiling point than cyclohexane like I’d expect, cycloheptane has a melting point of −12 °C, while cyclohexane has a melting point ...
-5
votes
0answers
22 views

Between benzene and pyrrole which more stable and why? [on hold]

Between benzene and pyrrole which more stable and why? By stability I mean lesser tendency to react. My guess: Pyrrole is a 5 membered resonating structure. Benzene is 6 membered resonating ...
6
votes
1answer
43 views

Why does acetate aldol with Evans auxiliary give almost no diasteroselectivity?

Following acetate aldol gives no diasteroselectivity: Because I don't know what the basis of above statement is (I heard it in a lecture and read it on some internet web pages). I expect the two ...
3
votes
0answers
39 views

Calculating Fluoride in toothpaste

I need help calculating the concentration of fluoride in toothpaste. Thanks in advance. A linear regression line was obtained; $$\log(\ce{[NaF]})~(\mathrm{mol~L^{-1}})~ \mathrm{vs~EMF}: y = 59.8x ...
-3
votes
0answers
41 views

Wine/water mixing problem [on hold]

The Water/Wine Problem is a classic logic problem that likely originated in the 1800s and was first published in 1896. The problem is usually stated something like this: Suppose your have two ...
0
votes
0answers
22 views

How can I use sunlight to heat a RBF and reflux a reaction?

This may seem like a off topic question but I really need help on it. I am currently working on a polymerization reaction in which I'm breaking down plastic polymers into smaller molecules. However, ...
1
vote
1answer
34 views

What makes many water soluble fertilizers blue?

I've noticed that water soluble fertilizers tend to be blue. What chemicals or chemical reactions cause this color here? Is this necessary or for aesthetic purposes? I haven't seen this in organic ...
0
votes
0answers
25 views

What do we mean when we say “atomic orbitals are directed towards more electronegative atom in a chemical bond” [duplicate]

I am studying about Bent Rule.And there it says that atomic p character tends to be directed towards the more electronegative element and atomic s character towards more electropositive element.Why ...
0
votes
1answer
39 views

What is the structure of NO2-?

I know that NO2 has 3 effective pairs, so it is likely to have trigonal planar structure. In trigonal planar structure we usually see three atoms bonded to central atom at 120°. But in NO2-, I ...
1
vote
1answer
33 views

Real space term for PPPM vs PME

I was under the impression that differences between the various long range electrostatic algorithms, ewald, PME, PPPM, to name a few, lied solely in their treatment of the reciprocal space term. ...
1
vote
0answers
19 views

Shapes of ionic compound

Can anyone explain the shapes of ionic compounds? What does it mean? What does the coordinate number mean? I know that in $\ce{NaCl}$, one $\ce{Na}$ atom is surrounded by 6 $\ce{Cl}$ atoms, and vice ...
2
votes
0answers
32 views

Can I successfully use a humidifier to distribute caffeine to wake someone up without the usual morning drowsiness?

Would I have any success putting coffee in a humidifier? Or perhaps water mixed with caffeine powder? So I could wake up without a jolting alarm clock, feeling like I already had a cup of coffee? I ...
0
votes
0answers
11 views

intermolecular interactions between polyethylene and polyamide in presence of a solvent [on hold]

What happens in terms of intermolecular interactions if you mix polyethylene and polyamide with a solvent?
3
votes
0answers
46 views

Does cyclobutanol undergo acidic catalysed dehydration?

In an exam I had to find a substance X for the following reaction to be correct: $$\ce{X <=>[\ce{H2SO4}] Y + H2O}$$ I picked cyclobutanol. My teacher said cyclobutanol is wrong . Why?
14
votes
5answers
2k views

Which substance has the highest temperature range between melting and boiling point

Which substances exist that are normally liquid and that will not freeze nor boil even at relatively low/high temperatures as compared to the freezing and boiling points of water? Or how can I ...
7
votes
1answer
43 views

Calculation of fluorescence quantum yield

The fluorescence quantum yield of a sample $\Phi$ is defined as the fraction of photons emitted per number of photons absorbed. The quantum yield is often calculated by comparing a sample with a ...
0
votes
0answers
25 views

About the proton exchange membranes fuel cell connect [on hold]

Why in the PEMFC stack connect is series connection but can increase current. In the PEMFC stack the anode(1) reaction produce H+ and e-. The e- through the bipolar plates to cathode(2).In logic the ...
4
votes
0answers
38 views

Why ginger reacts with sparkling water?

I think that the ginger ale is born this way. Anyway, if you put the ginger in a glass and add sparkling water, small drops splash out of the glass, the water is fizzier, more effervescent. Why? ...
5
votes
0answers
25 views

Which mechanics or law is predominately seen in nanoscale

Nanotechnology and sciences are the study or the manipulation of matter on an atomic, molecular, and supramolecular scale especially at nano meter range. We know that at macro molecular level a system ...
3
votes
1answer
48 views

Oxidation of Carbon atom in Alkene, Alkyne and Alkanes of functional groups?

Nomenclature priorities are in order of the degree of oxidation of the carbon atom. I am not sure if it's advisable to just take it as it is and use it or try to understand the basis of the ...
3
votes
2answers
45 views

Why does diffusion work in presence of similar atoms?

Studying biochemistry I noticed that equilibrium is reached for K and Na separately (not taking into account electric potential), as would be the case I assume for any molecule or atom. This is of ...
3
votes
1answer
24 views

Electroplating metal inside polymer foam with acetone

In my research we have a method of making polymer open-cell foams with high tortuosity and pore sizes on the order of 50–200 nanometers. I can make thicknesses of 100 µm to 2 mm thick (and up to 5 ...
3
votes
1answer
58 views

Complexity in computing the integrals involving higher angular momentum

I am quite familiar with Hartree Fock theory. However, writing it into program is an entirely different task, and that is where I have a couple of questions. I wrote a HF routine in Python a couple ...
3
votes
1answer
118 views

Is there a way to dissolve glue?

Background: I have a journal from my childhood. I applied glue (uhu brand. this one) to the papers almost 10 years ago. Q: Is there a way to dissolve the glue and make the pages readable?
5
votes
1answer
56 views

Average or individual molar heat capacity?

In finding enthalpy change $\Delta H$ during adiabatic, reversible expansion of mixture of two ideal gases $n_1$ mol of $\ce{A}$ ($C_{\mathrm{m},v}=\frac{3}{2}R$) and $n_2$ mol of $\ce{B}$ ...
6
votes
1answer
339 views

Chemicals in Urinal Odor Eaters

What chemicals are used in so-called urinal "odor eaters"? Do they actually destroy odors, or do they just mask them? Also, are these chemicals subject to any environmental laws or regulations?
5
votes
1answer
82 views

Identifying functional groups

Edited to combine each question in one picture, so I can just ask my question here. Okay. I've spent a few days googling functional groups and reading my text assigned on organic functional ...
-4
votes
0answers
43 views

An unkown substance present in urine with the empirical formula CH4N2O [on hold]

An unkown substance present in urine with the empirical formula $\ce{CH4N2O}$. $91\ \mathrm{mg}$ from the substance in $11.9\ \mathrm{g}$ $\ce{H2O}$ solution freezing point is $-0.233\ \mathrm{^\circ ...
-2
votes
0answers
32 views

why does benzoic acid acidic more than acetic acid? [duplicate]

What is the reason for benzoic acid being acidic more than acetic acid? When we are concerning cabocation stability it is little bit different of a phenyl and methyl group
4
votes
1answer
32 views

What determines the elastic limit of a substance?

from what I know, the elastic limit of a substance is the maximum amount of stress/force/pressure (a bit of confusion on my behalf here) a substance can withstand and still return to its original ...
-4
votes
0answers
38 views

Container A and Container B? [on hold]

Container A with volume $V$ in temperature $T_1$ contains 3 moles of He gas. Container B with volume $V$ in temperature $T_2$ contains 3 moles of Ar gas. If the root-mean-square speed of the two ...
-1
votes
0answers
28 views

How to prepare vitreous flakes of Boric acid?

Can anyone please tell me how to prepare vitreous slippery flakes of Boric acid (exactly like in the pic)?
1
vote
0answers
32 views

Is the pH of a solution (orange juice) affected by the presence of a metal?

Is the pH of a solution (orange juice) affected by the presence of a metal (aluminium, tin or iron for example)? I know that the metal will corrode in the presence of an acid (citric acid in this ...
-2
votes
0answers
20 views

Michaelis-Menten 2 [on hold]

In an enzyme-catalyzed reaction that follows the Michaelis-Menten mechanism, calculate the value of the Michaelis constant KM if the forward rate constant k1 is 4.3 × 10^6 L / (mol s), the reverse ...
-4
votes
0answers
25 views

Michaelis-Menten [on hold]

At 25 ºC an enzyme accelerates a reaction by a factor of 10^7 over the uncatalyzed reaction in water. If the effect of the enzyme is solely to reduce the energy of the transition state, by what amount ...
3
votes
0answers
19 views

PTFE (Teflon) combined with Silicon Polymers

I wanted to know if it would be possible to combine basic silicon polymers with PTFE in order to create a stable, non reactive silicon rubber that won't react to butane or other hydrocarbons in ...
2
votes
1answer
42 views

The proper explanation for the general formula of the DU? [duplicate]

I found a formula for the degree of unsaturation (DU) in Clayden’s Organic Chemistry. It explains, simply, the unsaturation with the difference in H atoms. Then I stumbled upon the general formula: ...
-3
votes
0answers
36 views

Following Hurricane Katrina in 2005, what oxidizer did cleanup crews use to eradicate the mold that grew in homes __________? [on hold]

Following Hurricane Katrina in 2005, what oxidizer did cleanup crews use to eradicate the mold that grew in homes __________? any suggestion or help please
-2
votes
0answers
32 views

NaHCO3 pH solution [on hold]

What is the pH of $1~\mathrm{mg}$ of $\ce{NaHCO3}$ in $1\ \mathrm{L}$ of pure water? My trial: I guess I have to find how many moles of the compound are in $1\ \mathrm{mg}$, the ...
3
votes
1answer
74 views

Difference between oxygens in a carboxylic acid?

I've been reading about MO theory and am wondering if the traditional model of carboxylic acids is correct. Usually, how it's presented is that the carbonyl carbon is doubly bonded to one oxygen and ...
9
votes
2answers
261 views

A monocyclic 6 carbon ring with 6 double bonds

I would like to know if this molecule has ever been synthesized, if not why not, and what would its IUPAC name be? Thanks a lot!
2
votes
0answers
50 views

What are good books about MO theory that don't require a lot of math background?

Are there any books about MO theory that explain the theory to a certain detail but don't rely on a lot of math background or explain the math within the book?
0
votes
1answer
27 views

Deviation of real gases from ideal behaviour

From the Amagat's curve we can see two types of result for real gases. If we increase pressure,the value of $PV$ decreases initially and then the value starts increasing for the gases like- carbon ...

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