# All Questions

29,902 questions
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?
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 ...
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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### 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 ...
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### 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 ...
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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### 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 ...
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### 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 ...
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 ...
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### 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 ...
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### 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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### 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 ...
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### 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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### 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. ...
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### 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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### 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 ...
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(...
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### 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 ...
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.
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### 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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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### 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 ...
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### 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 ...
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 ...
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 ...
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 ...
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### 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 ...
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### 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 ...
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### 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 ...
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 ...
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 ...
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 ...
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.
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### 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 ...
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### 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 ...
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### 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.
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### 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 ...
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### 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 ...
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 ...
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 ...
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'...
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
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### 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?
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 ...