All Questions

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0answers
2 views

Difference between oxo and formyl

What is the difference between oxo and formyl? both represent aldehyde when used as a substituent(correct me if I am wrong). But when should I use formyl and when oxo?
1
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1answer
16 views

How is hair tissue mineral analysis performed?

This might be a mixed chemistry / physics question, but I've always wondered what methods were used to precisely determine the levels down to trace amounts of all minerals in human tissues. I know ...
1
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0answers
7 views

Hydration, Coordinate Bonding, and Reduction Potential in Groups 1 and 2 Elements

Whenever an alkali metal such as Lithium is hydrated/solvated, coordinate bonding occurs and it is the high hydration enthalpy of lithium which makes it the strongest reducing agent in aqueous ...
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2answers
22 views

Where do negative ions migrate from the salt bridge to which electrode in the voltaic cell?

In the voltaic cell with $\ce{Mg/Mg^2+}$ and $\ce{Ag+/Ag}$, I am not sure whether the ions move from the salt bride to the $\ce{Mg}$ cathode or the $\ce{Mg^2+}$ cathode. I distantly recall my teacher ...
1
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0answers
26 views

Why isn't trinitramide planar?

The lewis structure of trinitramide has four major resonance structures, whereby the lone pairs of the central nitrogen can resonate with the nitro groups. This seems to indicate that each of the ...
1
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1answer
28 views

What makes a compound basic?

Aluminum chlorohydrate is often referred to as basic aluminum chloride. The pH value of ACH is about 4. How is basicity in this context defined?
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0answers
12 views

Creating a Solution [on hold]

I would like to create a 1.0 mM (millimolar) 100 ml solution that is a combination of water, sodium oxalate (from a 10 mM, 100 ml solution), and calcium chloride dihydrate (from a 10 mM, 100 ml ...
1
vote
1answer
35 views

Bond angle and bond lengths in Arginine

Based on the Lewis structure of arginine, the terminal primary amine attached to the guanidine group seems to be $\mathrm{sp^3}$ hybridized and trigonal pyramidal. Also, in quantum mechanical ...
2
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2answers
29 views

Colour of metal complexes with the same type and number of ligands

Crystal Field Theory says that because of d-orbital splitting caused by different ligands we have 2 different energy levels for d-orbitals. It also says that transition metals are coloured because ...
0
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1answer
23 views

Does Suncream have any affect or help protect against radiation

So I was just watching the HBO series Chenoybl and saw that people suffered various degreesvof burns from radiation form Uranium 235 and some were very minor and looked like a normal sun burn. My ...
1
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1answer
23 views

Products of the reaction between chromium(III) chloride, zinc and sulfuric acid

The aim of my experiment was to make a Cr(II) aquacomplex in situ, and for that I have the reaction: $$\ce{CrCl3·6H2O + Zn}$$ and I add concentrated sulfuric acid to it. I know that chromium(III) ...
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0answers
16 views

Entropy change in non-ideal solutions

We know that some solutions show positive deviations and some show negative deviation from Raoult's law.The former is endothermic and the latter is exothermic. And again, the volume change show ...
-1
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0answers
7 views

Electrochemistry problem- delta G [on hold]

What is delta G per mole of dichromate ions for the reduction of dichromate ions, Cr2O7 2-, to Cr 3+ by bromide ions, Br-, in acidic solution? (Hint: Use the standard cell potential.) (a) +26.3 kJ (...
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0answers
6 views

How to get the reagent masses if you know one of the product masses [on hold]

This is probably a really basic question, but say you have an equation like CH3COOH + NaHCO3 = CH3COONa + CO2 + H2O, and you know the moles of one of the products, like 0.02 moles of CO2 are produced. ...
-1
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0answers
8 views

Electron Affinity Trend down Group 2

Usually, electron affinities tend to become more negative up a group. However, for group 2, I saw that that is not the case. For example, Be and Mg both have positive electron affinities, Ca has -2 kJ/...
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0answers
19 views

Does the radius of the atom change when an electron is excited?

The radius of the atom increases when the electron in a hydrogen atom undergoes a transition from the 1s-orbital to a 2p-orbital. How is this possible? Why does exciting an electron to a higher ...
1
vote
1answer
34 views

I want to synthesis a diamine from fluorescein, but the efficiency of this reaction is very low, please help me

in this work, fluorescein was incorporated with an equal molar of 1-chloro-4-nitrobenzene and double potassium carbonate(molar ratio), the solvent of this reaction is dimethylacetamide (50(ml) for 5(...
1
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0answers
7 views

How do I go about either finding or calculating Aluminum-Oxalate salt solubility values in aqueous medium?

Water would contain other salts which may complicate things a bit. But finding out the Aluminum-Oxalate salts solubility values in pure water would be a good indicator already. It's for temperatures ...
-3
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0answers
11 views

Do Gamma-Keto Acids undergo Decarboxylation on heating?

I have studied that Beta-Keto acids get decarboxylize easily than any other position but is there any other possibility for Gamma-Keto Acids.
4
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0answers
9 views

Why are Born-Haber enthalpy calculations inaccurate for transition metal compounds?

A senior high/secondary school level exam question is about discrepancies between calculated and empirical enthalpies of formation. It asks why a discrepancy “usually” exists for d-block compounds ...
0
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0answers
23 views

Why doesn't standard Gibb's Free Energy decide spontaneity? [on hold]

I know that Gibb's Free Energy decides the spontaneity of a reaction. But why doesn't standard Gibb's Free Energy decide spontaneity? Standard Gibb's Free Energy is basically Gibb's Free Energy at ...
0
votes
1answer
27 views

is every molecule either a base or acid

I read today that water is a base because it can receive a proton when mixed with some acids. That got me thinking: is every single molecule capable of either donating or receiving a proton -- when ...
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0answers
19 views

Do temporary dipoles form in silicon(IV) dioxide?

Textbooks only ever mention covalent bonds between silicon and oxygen atoms in silica. However, as electron movement is random, one end of a silicon atom in a given instant could be more positive than ...
1
vote
1answer
32 views

Temperature and pressure for three phase equilibrium of aqueous sodium chloride solutions

I am currently investigating the effect of adding Salt(NaCl) to water on its triple point. Let us assume the mass ratio of water to NaCl is $1:1$. I asked a similar question previously. But, I still ...
2
votes
1answer
22 views

Evaluate indicator choice (phenolphthalein)

A student wishes to find the concentration of a $\pu{50 mL}$ solution of acetic acid $(K_\mathrm{a} = \pu{1.8e-5}).$ He performs a titration using a solution of $\pu{0.2 M}$ sodium hydroxide. The ...
2
votes
1answer
25 views

Iron(III) nitrate and hydrogen peroxide reaction

When iron(III) nitrate is added to hydrogen peroxide as a catalyst, the temperature initially decreases and begins to increase after 30 seconds. Why is this the case? (is there any intermediate ...
0
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0answers
7 views

APTES GOPTES (silane lenkers) hydrolysis and storage?

The problem of usage epoxy/amino silanes is that they are subjected to hydrolysis of their ether sites by the water contained in the air. How fast is this hydrolysis and how to store those silanes ...
1
vote
1answer
37 views

Priority to longest carbon chain or double bond? [duplicate]

Priority to longest carbon chain or double bond? Above structure and its nomenclature is given in my notes. However, I suspect it is wrong because the Carbon chain of 8 instead of 7 is available. So ...
2
votes
1answer
26 views

Rearrangement considerations in feasibility of SN1 in given reactants

I have been asked to compare the feasibility of Unimolecular Nucleophilic Substitution ($\mathrm{S_N1}$) in the following question. I have received instruction that the reaction will be feasible only ...
2
votes
2answers
50 views

Energy absorbed by a system in isothermic process in which the phase changes from liquid to gas

A system contains $x$ mole of material, with surface area $S$ is pressed by a mass $M_1$ (no fraction and no any other outer forces involves). Let $\Delta H_\mathrm{l\rightarrow g}$ be the transition ...
1
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1answer
15 views

Solvents and Enzymes

I was reading recently about environmental remediation being done, using an esterase to break down / neutralize cocaine that had contaminated waterways in Europe. Are there similar enzymes that can be ...
-1
votes
0answers
16 views

electric potential of a redox reaction

I'm wanting to know how to figure out the electric potential of a redox reaction with the following half reactions: $$\ce{S (-II) - 8e- -> S (VI)}$$ $$\ce{4O(o) + 8e- -> 4O(-II)}$$ I can't find ...
1
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0answers
33 views

What chemical reaction could be used to make copper pennies a vibrant red?

I’m an artist working on a piece using pennies to illustrate my drawing and I need my pennies to be red in a certain portion. I’m trying not to use paint and was wondering if there was a way to make ...
0
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0answers
24 views

Comparing the emission spectrum of ethanol and mixture of alcohols

Sorry if this question has a simple answer, but I've been unable to find it elsewhere. Using a diffraction grating, burning ethanol (99.9%) will produce a rainbow of colours. However, when burning ...
1
vote
0answers
20 views

Significance of isotope mixtures for electrospray ionisation mass spectrometry

A follow-up question to Why are isotopes an issue in reading mass spectra?: in the case of electrospray ionization (ESI), the charge of an analyte can be >40, does the difference in mass of different ...
-3
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0answers
27 views

Old chemical reaction mechanism under quantum chemistry? [on hold]

Quite a few old chemical mechanisms are explained via the old atomic models. After the discovery of quantum chemistry, we have a new atomic and molecular theory like MOT. So how do this old mechanism ...
-2
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0answers
28 views

Can a strong base (in this case Sodium Hydroxide) be effectively weakened ie: safe without the neutralization of it? [on hold]

I wish to figure out If I can retain Sodium Hydroxides ability to hydrolyze fats yet allow it to be safe to humans. I was curious if it were possible without the neutralization of the base.
0
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0answers
28 views

Why is there visible liquid (possibly water) on matches when they're burning?

I was just burning a normal standard match and I observed visible liquid running down the wooden shaft as the fire burns and consumes it, what could explain such phenomenon ? could it be that the wood ...
-1
votes
0answers
22 views

Difference between Ascorbate & Semi-DHA (both C₆H₇O₆)

I wanted to know how Sodium Ascorbate functions in the AA family of molecules. However, all normal routes lead to dead ends (typically AA). Forcing NCBI to search only for Sodium Ascorbate mostly ...
2
votes
2answers
41 views

Which salts can be used to precipitate chloride ions?

We don’t have AgNO3 in the lab. I have no idea what else can be useful. I am washing a product and I want to make sure the chlorides are washed away.
-2
votes
0answers
11 views

Gold retrieval from electronics [duplicate]

I have a question about a process of extracting gold. A friend of mine follows this procedure: He put the core of an electronic in 50percent solution of HNO3 for 2 hours. After filtering we gather the ...
4
votes
1answer
64 views

How to calculate S² value of a broken-symmetry wave function?

$S$ represents spin, signifies the number of unpaired electrons in the system. For example, if the number of unpaired electrons is $1$, then $S=1/2$. $S^2$ is calculated as $S(S+1)$. From what I have ...
-1
votes
1answer
65 views

Burning magnesium ribbon [on hold]

I know that this might sound wrong but, in the reaction $$\ce{2 Mg(s) + O2(g) → 2 MgO(s) + energy}$$ isn't oxygen supposed to be oxidised as it has excess electrons $(\ce{O^2-})$ and can donate a ...
0
votes
1answer
50 views

Polyethylene glycol [on hold]

I used a product on my family containing 90 percent Polyethylene glycol. Now I’m reading how Polyethylene glycol can be contaminated with ethylene oxide and also the lower the weight the higher the ...
1
vote
0answers
25 views

Plutonium element configuration

For Plutonium 94 when I do it's element configuration I get 1s2-2s2-2p6-3s2-3p6-4s2--3d10-4p6-5s2-4d10-5p6-6s2-4f14-5d10-6p6-7s2-5f6 I found on this site that I'...
-2
votes
0answers
19 views

What is the pH value of 0.8M CuSO4 [on hold]

really need to know how 0.8M CuSO4 will influence the acidity of
-2
votes
0answers
10 views

What is the molar Mass of Cu2+? [on hold]

How can i find out the molar mass of copper by doing an Reduction from a Cu2+ to Cu (with an electrolysis) and which formula do i need?
-1
votes
1answer
44 views

Synthesizing amino acids - why sodium hydroxide goes after certain bonds [on hold]

everyone. In the following reaction, what is it that causes NaOH to attack either bond A or B over all the other bonds available? Subsequently, why does NaOH not continue with bond B once bond A has ...
2
votes
1answer
77 views

Quantify the effectiveness of baseline correction in Raman spectra

I've produced several thousand Raman spectra using hyperspectral imaging techniques. These suffer from significant fluorescent interference which produces a curved, sloped baseline. Using Matlab, I ...
-1
votes
0answers
20 views

How to determine which liquid has higher antioxidant content?

If I have two solutions with me and I want to find out which one has a greater antioxidant content then how can I experimentally find that out in a laboratory? What are the chemical reactions? The two ...

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