All Questions
0
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0answers
13 views
Solving carbon black
I want to remove a layer of 2 mm thick carbon black on a copper bowl. I have tried different solvents, but the carbon seems to be very resistive.
Which formula solves carbon black without solving ...
0
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0answers
16 views
How to calculate mole fraction of each element in an ionic compound?
A solution is prepared by dissolving 518g of K2SO4 in a small amount f water and diluted it with water to a volume of 2.5L(calculate the mole fraction of water,K+,SO4-2)
I got that the mole fraction ...
0
votes
0answers
16 views
How to calculate molarity,molality, vapor pressure, freezing point, boiling point?
A solution is prepared in a cold room(4.0 C) by dissolving 118g of potassium nitrate(KNO3) in 750 mL of water. The resulting solution had a volume 745 mL.
Calculate the molarity of the resulting ...
0
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0answers
25 views
HCl synthesis from sulfuric acid and sodium salt
I'd like know if this is right. The reaction between $NaCl$ and $H_2SO_4$ should yield $HCl$ and sodium sulfate. This is a double substitution, true? No oxidation took place here. The thing is, when I ...
1
vote
2answers
24 views
On the scale of stuff with a pH
I am a confused (and somewhat anal retentive) non-chemist who is trying to understand what pH is. I have come to understand it is a measure of acidity, but I have not yet figured out what that means ...
0
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0answers
16 views
GAMESS Firefly Bond Dissociation Energies and Bond Energy
I'd like to calculate Bond Dissociation Energy and Bond Energy of ATP to a similar molecule. I was told GAMESS or Firefly (pcgames) are able to do this Computational Bond Dissociation Energies and ...
0
votes
1answer
18 views
Is energy required to form bonds [phase change]
My question is if any energy is required to form bonds, for instance when there is a phase change?
If I am correct, energy might be required in the beginning, to make the reaction start and then ...
0
votes
1answer
19 views
Computational Bond Dissociation Energies and Bond Energy
I'd like to calculate Bond Dissociation Energy and Bond Energy for ATP to a similar molecule. What free (at least for academic use) computer programs will do this.
0
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1answer
26 views
Where did the acac come from in Cr(acac)3 synthesis by CrCl3 reagent?
Those are the reactions:
$$\ce{(H2N)2CO + 3 H2O -> CO2 + 2 NH4+ + 2OH-}$$
$$\ce{CH3COCH2COCH3 + OH- -> acac- + H2O}$$
$$\ce{CrCl3.6H2O -> Cr3+ + 3Cl- + 6H2O}$$
$$\ce{Cr3+ + 3acac- -> ...
0
votes
1answer
34 views
Easy to do experiments that clearly show outstanding properties of graphene
By chance we received for free some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires at our University. I would like to prepare some very easy to do experiments for the ...
1
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0answers
24 views
PEG (polyethylene glycol) and ITO (indiumtinoxide)
The binding of proteins to an ITO surface can be prevented by coating it with PEG groups (polyethylene glycol). PEG-silane is used to create the coating.
can somebody help with:
*Why does PEG silane ...
2
votes
1answer
44 views
Chemical methods to extract Oxygen from Rust
Let's say I have a large quantity of rust and want to extract the oxygen from it in a way that allows me to collect the oxygen in a container.
What chemical process can I use to do this and what ...
0
votes
0answers
25 views
Make CaMnO3 crystal structure with Avogadro
The question is exactly as the title suggests .. i can't figure out how to make bonds between unit cells. Any help?
0
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0answers
20 views
How can diesel fuel produce less carbon monoxide but more carbon particulates?
My guess at why diesel produces more carbon monoxide is that more heat is required for combustion of diesel fuel, so there is therefore less incomplete combustion, so rather than carbon monoxide being ...
1
vote
1answer
33 views
In Goodman and Gilman what does R,S-citalopram refer to?
In Goodman & Gilman's The Pharmacological Basis of Therapeutics, 12e R,S-citalopram is referred to. The problem is that from what I am aware of citalopram only has one stereocentre, and hence I am ...
0
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0answers
15 views
How Does The Mordant, Ferric Acetate, Interact With Tannins When Ebonizing Wood?
Ferric Acetate (II) and (III) are "mordants," which intensify wood staining in direct proportion to the tannin concentration in the wood. Some wood stainers add tea to increase the tannin content and ...
0
votes
1answer
28 views
What Is This Colorless Ferric Solution?
I made a solution of Iron acetate through placing steel wool in 1L of acetic acid (vinegar 5%) and adding a few tablespoons of hydrogen peroxide of questionable age. The solution turned a nice brown ...
0
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0answers
26 views
Do you use an electronic lab notebook? [closed]
As I said; do you use an electronic lab notebook? If so, which one, and if not, why? I'm trying to design my own notebook and am looking for neat features that people think are useful, or things to ...
0
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0answers
29 views
Why calcium chloride is used to melt ice over sodium chloride
I'm not quite sure I understand this. My question is:
Calcium chloride is a salt used widely to melt ice on sidewalks and roads. Explain why one mole of $\ce{CaCl2}$ would be more effective ...
0
votes
0answers
26 views
I need the mathematical equations that represent the absorption of CO2 in a column
I want to mathematically model a carbon dioxide absorption column using the equilibrium model (not rate based or dynamic) but I am having trouble finding the same number of numerical equations as I ...
-3
votes
1answer
50 views
The most common elements in functional group [closed]
My question is what are the most two common elements in functional groups?
0
votes
0answers
31 views
Calcium carbonate and hydrogen phosphate producing calcium phosphate, carbon dioxide and water
How does the balanced reaction look for these compounds? I found that phosphoric acid instead of hydrogen phosphate creates a much easier problem, but the teacher said hydrogen phosphate and I can't ...
0
votes
0answers
29 views
Resisting phosphorlazation by ATP/ADP/AMP
AZT is a triphosphaste nucleoside which ATP binds to by way of a protein 3KLE. I have another chemical and I want to know if it will form a dinucleoside. Can someone tell me which computer program ...
0
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0answers
24 views
Why does the Förster resonance energy transfer exhibit $\frac{1}{r^6}$ scaling?
The title more or less contains my question - why does the Förster resonance energy transfer (FRET) (photon?)-based energy transfer mechanism, which folks sometimes use as a spectroscopic ruler to ...
0
votes
0answers
13 views
Reverse Rates in SSH Theory
I am currently implementing V-V transitions for $N_2$ in a code I work with. For now, I am only using Schwartz-Slawsky-Herzfeld Theory for this, and will move on to more accurate/sophisticated ...
0
votes
1answer
27 views
Find the volume of the CO2 product
I've been stuck on this for some time, so I decided to ask you. Below you can see the chemical reaction I'm working with:
$\ce{CH_3CH_2OH(l) + 3O_2(g) → 2CO_2 (g) + 3H_2O(g)}$
I've got so far:
How ...
0
votes
0answers
22 views
Dispersion system breaks when ph-balance changes
So... why? It breaks when Ph-balance getting lower and both when it getting higher. Why?
0
votes
1answer
17 views
Can I synthesize salicylic acid from salycylaldehyde?
I have a homework set about synthesis. One of the questions is:
You have a bottle of salycylaldehyde. And you want to make salicylic acid from salicylaldehyde. You can use all reagents and ...
0
votes
1answer
26 views
Why is periodicity seen in these certain properties?
I missed my lesson on periodicity so had to teach myself, and have always forgotten to ask my teacher to explain to me why these trends are seen, which, unfortunately, the textbooks don't.
Density: ...
1
vote
0answers
23 views
Can I maintain a constant relative humidity using saturated salt solution, at greater than atmospheric pressure?
At atmospheric pressure and between temperatures of $\sim 0$ to $100^\circ C$, well known relationships between established humidity and given saturated salt solution are available. I.e. ASTM E104 ...
1
vote
1answer
34 views
What does reaction exothermicity say about the stability of molecules
If a reaction is exothermic it means that the energy state of the products is lower than that of the reactants so this will be the state that 'nature' will naturally strive for. Often you see that ...
0
votes
0answers
19 views
Butane Burning Color
Why does Butane burn blue? From my (very) basic understanding of chemistry, carbon and hydrogen do not burn blue, their radiation spectra are different-so why should the combination burn blue?
Please ...
1
vote
2answers
36 views
What does it mean for a reaction to favor the reactants/products?
(This example is purely hypothetical.)
You have the reaction $$\ce{H2(g) + O2(g) <-> H2O2(g)} \text{(500K)}$$
The reaction reaches equilibrium at the following concentrations:
$$\ce{[H2]} = ...
1
vote
1answer
45 views
Why x in equilibrium calculations can be “ignored”
You don't need to work out anything for me. I am just giving an example so you can explain something to me.
For example:
$$\ce{ClF3(g) <=> ClF(g) + F2(g)}\\ \ \ K_c=8.77\times10^{-14} \ \ @\ ...
0
votes
1answer
41 views
Finding pH using pKa
The Q a) is calculate the pH of a solution made by mixing 57.5ml of 0.160M ammonium chloride ($\ce{NH4Cl}$) with 60.0 ml of 0.260 M ammonia solution
b) calculate the pH of the above buffer colution ...
0
votes
0answers
24 views
Entropy of activation
In Price & Dwek, I find a small section discussing entropy of activation for three examples
$$
1: \ce{Ce^{4+}} + \ce{EDTA}^{4-} \rightarrow (\ce{CeEDTA})\\
2, \text{S}_N\text{1 reaction}: \ce{AB} ...
0
votes
0answers
13 views
alpha/beta polysaccharides
In polysachharides like sucrose or any other disachhaharides , how is it that we assign whether the glycosidic bond is alpha/beta ?
For example the images here: ...
1
vote
2answers
62 views
When did the atom Theory Become indisputable?
We know that the Greeks were the first scientists (or better, philosophers) to introduce the idea that matter is made up of little “chunks”, and they named these chunks “atoms”. This idea that matter ...
0
votes
2answers
28 views
Does a rotary evaporator need a draft chamber and a vacuum pump?
I am using DCM ( dichloromethane) in my research, as a solvent. At the end of the day I have to separate the salute and measure it.
Up until now, I have been using a constant temperature oven, set a ...
0
votes
1answer
21 views
What Could Formations of Linkage Isomers of [Co(NH3)NO2]^2+ be like ?
I am trying to draw the structure of this complex [Co(NH3)NO2]^2+ ,however I am not sure if the linkage isomers of this complex like this ;
0
votes
0answers
20 views
Calculate the pH of a solution given [OH] [closed]
I need to calculate the pH of a solution with $[\ce{OH}^-] = 3.16*10^{-10} $. If somebody could explain to me how to obtain the answer or walk me through it that will be great.
1
vote
1answer
26 views
Conducting current in electrolytes
I keep trying to figure out how current is conducted through an electrolyte but all I can find are BS half answers. They say the ions conduct, but the specifics are poorly explained or absent. I ...
0
votes
1answer
21 views
Plastic: Reputable Publications
I would just like some reputable textbooks and or publication companies that have extensive research on plastics, as, for example, dealing with life cycles of plastics, degradation factors, effect on ...
2
votes
3answers
57 views
Le Chatelier's Principle: How can the equilibrium shift, while Kc remains constant?
The answer is D.
I understand that when more H+ ions are added, the reaction shifts in reverse.
So I've understood that this is known as having the equilibrium shift to the left, toward the ...
2
votes
0answers
38 views
Total magnetic moment of atom
Whenever I read about coordination compounds in my textbooks, I always find a discussion about spin-only magnetic moment which is given by $\sqrt{n(n+2)}$ BM,
Where $n$ is the number of unpaired ...
0
votes
1answer
49 views
Buffers calculating amounts of acid & base
Quick run down, I was given ph OF BUFFER 4.5 AND THEN pKa of acid 4.79
I then had to work out volume of acid and volume of base using pH=pKa+log10([a^-1]/[HA])
using that I calculated the volumes of ...
0
votes
1answer
41 views
Markownikoff's addition to halogenated alkene?
The justification or rather intuition behind Markownikoff's rule is the stability of intermediate carbocation. The more substituted the carbocation the more stable the product. But based on this ideas ...
0
votes
1answer
30 views
How do I know if concentration of Ammonia affected my absorbency measurements?
This is for determination of copper in a penny Lab. After making standard solutions we made a solution with a penny, dissolving it in nitric acid and adding ammonium hydroxide to form a more ...
0
votes
1answer
37 views
Why are the vinylic bonds in alkenes slightly polar?
when searching in the internet about why are alkenes more polar than alkanes (but still they are non-polar), they are always saying that the double bond is more polarizable , i understood the whole ...
1
vote
0answers
30 views
Degradation mechanism of hydroxymethylfurfural to 2,5-dioxo-3-hexenal and 4-oxopentanoic acid
I want to understand the degradation mechanism of hydroxymethylfurfural (HMF). According to the Wikipedia article, HMF is degraded in honey. Someone said that the degradation proceeds via 2 possible ...
