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12 views

Can nanotechnology reverse the effects of moldy food?

I was reading an article from Wired’s Artifacts from the Future; where a hypothetical future cooking station has a feature called “Nanobot De-molder” which I assume takes moldy food and then gets rid ...
-1
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0answers
8 views

Mass concentration question with calculations [on hold]

20cm3 of hydrogen peroxide solution of unknown concentration reacts with 12.15cm3 0.04 mol/dm3 of potassium permanganate solution in sulfuric acid media. Calculate the mass concentration of hydrogen ...
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0answers
24 views

Is paraformaldehyde safe as a catalyst in cosmetics?

I am making a new body wax to sell. I have a supplier that is selling a very interesting ingredient but I happen to know it contains paraformaldehyde. They claim there is no formaldehyde left in the ...
3
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1answer
16 views

Why does the viscosity of honey decrease when mixed with other viscous fluids?

In order to make honey mustard, I mix honey and mustard. But the resulting mixture is less viscous then both honey and mustard. How does mixing two viscous substances give a less viscous one?
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0answers
21 views

How to control nucleation of NaCl crystals?

In addition to a previous question I posted, I have a second question. The previous question I shall link here: How to counter crust formation when crystallizing NaCl on the liquid-air interface? ...
1
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1answer
22 views

Is enthalpy of combustion the 'heat released' or 'enthalpy change'?

In a constant volume calorimeter, $\pu{3.5 g}$ of a gas with molar weight $\pu{28 g}$ was burnt in excess $\ce{O2}$ at $\pu{298 K}.$ Temperature of calorimeter increased from $298$ to $\pu{298.45 K}$ ...
-1
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0answers
11 views

Calculating the enthalpy and entropy [on hold]

I would like to know the answer and comment of this question Caculate the enthalpy and entropy changes of1mol Diopside as it is heated at 1atm from 600k to 1000K. Standard state of 298.15K and 0....
-2
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0answers
16 views

Movement and Position of Electrons in Atoms and Compounds with respect to various models

This may sound vague, but here goes. I've often wondered how electrons revolve in compounds (and not just atoms). That was before I came across various theories / models of the atom and I found out ...
3
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0answers
21 views

What gas would be suited best to form a density gradient in a long tube?

I want to set up an aero-optics experiment using a sealed ~5 m length of pipe with a gas inside. The gas must form a density gradient, and must be transparent enough to view a target at the other end ...
1
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0answers
18 views

Which has more lattice energy calcium oxide or calcium carbonate?

Which has more lattice energy calcium oxide or calcium carbonate? Calcium carbonate can get polarized. Does this have anything with lattice energy value compared to calcium oxide?
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0answers
23 views

Can I use the quasi-equilibrium approximation when drug and ligand distribution volumes are different?

A drug $D$ binds a ligand $L$ to form a complex $C$ according to the law of mass action. Furthermore, mass balance should be achieved. Can I still assume quasi-equilibrium when the distribution ...
-3
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0answers
13 views

How can I calculate molar concentration from a precipitate? [on hold]

In a sample of water, $V=\pu{1000 mL}$, I found the concentrations of $\ce{Mg^2+}$ and $\ce{Ca^2+}$ ions that cause the hardness of the water. Then added enough $\ce{Na2CO3}$ to get $\ce{MgCO3}$ and $\...
2
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1answer
49 views

How does the splitting in this molecule take place?

Consider the following molecule and data: $$ \begin{align} \mathrm{H_a} &= \pu{1.0 ppm} &\quad J_\mathrm{ab} &= \pu{5.0 Hz}\\ \mathrm{H_b} &= \pu{3.0 ppm} &\quad J_\...
1
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0answers
22 views

Right Raman Spectrum of Cyclohexane

In this site, https://www.princetoninstruments.com/userfiles/files/assetLibrary/Technical%20posters/Poster-Aberration-Free-Raman-Spectroscopy-with-the-IsoPlane.pdf the raman spectrum of cyclohexane ...
1
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0answers
15 views

Factors affecting order of heat of combustion

I was asked the following question in Ai²TS-4 FIITJEE test: What is the correct order of heat of combustion of the following compounds: I started with the solution by counting number of \alpha-H ...
0
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1answer
19 views

About Fe(III) and Fe(II) coordination complexes

Why does Fe(III) form octahedral coordination complexes if it has 5 electrons in its d-orbitals? I understand that Fe(II) has 6 electrons in its d-orbitals and 6 lone pairs from 6 ligands as the 12 ...
-2
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0answers
9 views

Effect of electronegativity [on hold]

Explain the effect of electronegativity when the surrounding atom is the same with different central atom having lone pair,refer to the second point of effect of electronegativity in Blockquote JD ...
7
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2answers
837 views

Explanation for why nickel turns green in hydrochloric acid

My daughter has a chemistry test that I am helping her prepare for. One question is Nickel sulfate, $\ce{NiSO4(aq)}$ is a green solution. Nickel chloride, $\ce{NiCl2(aq)},$ is a yellow solution. If ...
1
vote
1answer
23 views

Size of target substance in IR and Raman Spectroscopy

Usually what is the size (in nanometer) of the sample or target substance in IR and Raman Spectroscopy? Which one has largest size of sample it can scan, how many molecules or atoms are involved? If ...
-3
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0answers
25 views

The mechanism of separating AlCl3 [on hold]

For this question I have gotten to: I know I am supposed to separate the $\ce{AlCl3}$ through aqueous work up, but I am not sure what the mechanism is. The resulting answer is the enol/keto form + $\...
2
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1answer
27 views

Hyperconjugation in bridged carbon systems

While studying about hyperconjugation, I came across the following compound which posseses one α-hydrogen (with respect to the $\mathrm{sp^2}$ hybridised carbon atom with an empty $\mathrm{p}$-orbital)...
-3
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0answers
17 views

What determines how substances should be stored? [on hold]

(Що впливає на умови зберігання речовин) Some substances can be stored solely dissolved, others only pure. Give at least two fundamentally different examples of both organic and inorganic substances ...
-3
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0answers
55 views

Do you know a material containing all these elements? [on hold]

I would like to know that maybe this matter.
1
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2answers
36 views

How is energy not stored in bonds? [duplicate]

Consider the paraphrase from Ebbing: It takes energy to break bonds & energy is released when bonds are formed Let's look at the first statement It takes energy to break bonds. Is this true ...
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0answers
11 views

Voids around each sphere [on hold]

My physical chemistry book says that "Number of triangular voids around each sphere are 24 or in other words voids per atom in crystal are 8." Is there a way to deduce this result like we do in ...
-1
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0answers
7 views

Whats the matter with ignition and cooking point [on hold]

Why does gasoline have a boiling point, but when we heat it, it will combust?
-2
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0answers
24 views

Why isn't Kw = ([H+][OH-]) / [H2O], when H2O is the reactant?

For the hypothetical reaction: $$ \ce{A <=> B + C}$$ the equilibrium constant expression is written as $$\ K= \frac{[\ce B][\ce C]}{[\ce A]} $$ So, why is $ K_\mathrm w $ written as: $$ K_\...
6
votes
1answer
50 views

Is black tea a pH indicator?

Today, I made a cup of lemon tea in a different way than usual. Instead of pouring hot water in to a mug containing lemon juice and black tea (my normal routine), I let the tea steep for a little ...
-1
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0answers
30 views

Ionic Silicon Compounds [on hold]

Are there any strong acids that react with silicon to produce an ionic silicon compound? I’m referring to a “saltlike” silicon compound that dissociates in water to produce “silicide” ions.
0
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1answer
48 views

Isolating barium(II), copper(II) and zinc(II) from aqueous solution [on hold]

Q15 Each metallic ion was separated from an aqueous solution containing $\ce{Ba^2+},$ $\ce{Cu^2+},$ and $\ce{Zn^2+}$ by the procedure shown in the following figure. From ①–⑥ in the table below choose ...
-2
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0answers
22 views

Why highly electropositive elements form strong bases? [on hold]

I know that elements like sodium form hydroxides which completely dissociate in water but why do they dissociate more than others like magnesium hydroxide? Does reactivity has a role here ?how?
-1
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1answer
9 views

Electrophilic base / nucleophilic acid / basic electrophile / acidic nucleophile [on hold]

What I was understanding is that all bases are nucleophiles and acids are electrophiles means the condition for them is same and all nucleophiles are basic and all bases are nucleophiles and same for ...
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0answers
15 views

General way to identify number of node of an arbitrary wave function [on hold]

Assume an arbitrary wave function, how we can identify number of its node?
-1
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0answers
5 views

Where can I find flux formulation for different solder composition? [on hold]

I am looking to make my own soldering flux and want to understand where do I get started?
2
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1answer
133 views

Spectra from Dipole Moments [on hold]

If there is a change in dipole moments such as absorption spectroscopy, there are infrared absorptions (and/or transmittance) corresponding to them. Is the reason change in dipole moments are in ...
0
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0answers
12 views

What trend exists in the enthalpy change of reaction of group 2 carbonates with HCl

I am currently investigating the trends in enthalpy change of the reaction of group 2 carbonates with HCl. As per ion polarization theory there should be an upward trend in stability and thus a ...
0
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0answers
34 views

Confusion with IUPAC naming of Morphine

I'm having trouble understand what sections of the molecule morphine relate to what sections of its corresponding IUPAC name of (4R,4aR,7S,7aR,12bS)-3-methyl-2,4,4a,7,7a,13-hexahydro-1H-4,12-...
0
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0answers
16 views

Does any body know which organic solvent can solute LiOH? [on hold]

Does any body know which organic solvent can solute LiOH? Very very very thanks for your answer ><
-1
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0answers
21 views

Hydrochloric Acid Melting Point [on hold]

Is there a specific reason why hydrochloric acid has a negative melting point of -114.2 degrees Celcius?
-1
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0answers
7 views

Derive # of atoms of a certain element in a compound given compound weight [on hold]

The answer is listed as (a) on the answer key. This is likely 99% accurate but there is a very small chance (a) is not correct.
1
vote
1answer
51 views

Why is the carboxyl proton in salicylic acid more acidic than the phenol proton?

I know I'm just wrong about this but I'd appreciate some help seeing why. It seems to me like the phenol proton in salicylic acid should be more acidic than the carboxyl proton. When I try to draw ...
0
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0answers
24 views

Major Organic Product of pheylpropene and diazomethane? [on hold]

What is the major organic product synthesized from phenylpropene and diazomethane? I get that N2 from the diazomethane is going to be the leaving group correct and it forms the carbene :CH2 correct? ...
-3
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0answers
19 views

Melting Points Because of Electronegitivity [on hold]

Why is sodium iodides melting point lower than calcium chloride?
-1
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0answers
35 views

Diels-Alder - aromatic compound - mechanism [on hold]

I am trying to figure out a mechanism for the following reaction but I am sort of lost and I can't find anything that would help me... All the reactions I found are "pretty easy" to solve... Thanks ...
1
vote
0answers
23 views

Calibration curves and dilution factors

I am currently taking a course where we are exploring nitrate concentrations in water samples. We are using a UV-Vis Spectrophotometer and have created a calibration curve in the first part of the ...
-1
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0answers
30 views

Is there an economical way to neutralize sodium in compost? [on hold]

I have compost that has too much sodium. It has a CEC of over 50 due to high organic matter, so washing the sodium out takes a lot of water. (About 3 times the volume of soil.) Currently there are ...
-2
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0answers
30 views

Non-Metallic properties shown by some metals [on hold]

I want to ask why Li, Be and Mg which are metals show Non-Metallic properties. I know they have small atomic size and high electronegativity as compared to other metals, but I don't know the reason ...
0
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1answer
26 views

Cross-conjugation

Could somebody please explain the concept of “cross-conjugation” (Organic Chemistry) to me? In what kind of conjugated systems is it observed, what are its effects on resonance of the system as a ...
-3
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0answers
13 views

Solution mixture help please [on hold]

What is the ratio two solutions of H2SO34 have to be mixed in order to result a 20 percent H2SO4 solution The two solutions are 2.06M with a density 1.125 grams per ml H2SO4 2.a solution with 25 ...
2
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0answers
20 views

Varying sizes in LUMO of acrolein

I want to ask a question about the varying sizes in the LUMO of acrolein during a 1,2- or 1,4-addition. Today in our introductory lesson to Organic Synthesis with 1,2- and 1,4-addition we were ...

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