All Questions
45,375
questions
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Why would the theoretical pH not match the measured pH when performing a titration of NH4OH with HCl?
I ran a weak base - strong acid titration experiment using an automatic titrator. I started with an aqueous ammonia stock solution (somewhere in the range of 0.1 - 2.5 wt.%) that was left open to ...
- 29.1k
0
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0
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Can Gibbs Free Energy equation be used to explain why some phase changes are exothermic or endothermic?
I was wondering about some ways to explain why some phase changes are exo / endo.
I am aware that for endothermic phase changes (boiling, melting, sublimation) energy input is required to raise the ...
0
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[Zn(edta)]2- optical activity?
hey guys this is my first time asking a question on stack exchange so not really sure about the format but here's my attempt
[Zn(edta)]2-
So in this compound the ligand EDTA is apparently optically ...
- 38.4k
6
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1
answer
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Treatment of ketones with excess Tebbe reagent
The reaction in black below was presented in a set of lecture notes as an example of the use of the Tebbe reagent, however it's not immediately obvious (to me, at least) that the product should be the ...
CommunityBot
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off-resonance Raman and normal Raman spectra [closed]
What is the difference between the off-resonance Raman and normal Raman spectra in gaussian? How to calculate the off-resonance Raman spectra in gaussian?
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determine the percentage of nitrogen Amide nitrgen - Nitrate nitrogen - organic nitrogen [closed]
Is there a way to determine the percentage of nitrogen according to its source using the Kjeldahl device?
Amide nitrgen - Nitrate nitrogen - organic nitrogen
26
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3
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141k
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Why does chlorine have a higher electron affinity than fluorine?
Since fluorine has its valence electrons in the n=2 energy level, and since chlorine has its valence electrons in the n=3 energy level, one would initially expect that an electron rushing towards ...
- 59.5k
4
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answers
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NMR pulse sequence for precise measurements of coupling constants?
The usual procedure for measuring $J$ coupling constants in NMR is to record a 1D spectrum and estimate the constant from the differences of peak frequencies. Fitting the spectrum to a lineshape ...
- 822
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2
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What are the units of equation 13 of Buckingham's 1960 paper about chemical shift influenced by electric field?
Has anyone read Buckingham's 1960 paper 'CHEMICAL SHIFTS IN THE NUCLEAR MAGNETIC RESONANCE SPECTRA OF MOLECULES CONTAINING POLAR GROUPS'? I'm having trouble understanding Equation 13 regarding the ...
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How to interpret molecular orbital (HOMO - LUMO) plots in Chem3D 22.0?
Recently, I have been trying to understand the origin of the difference in reactivity of alkynyl-boron(ate) complexes so I tried to generate a molecular orbital plot on Chem3D (Version 22.0.22 64bit) ...
- 1,282
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Cat litter crystals causing toxic smell upon rubbing and pouring out of the package, safe?
I am under-educated in terms of chemistry hence the question and assumptions.
Basically, for our cats, we are using what seems to be the latest scientific achievement in litter sand - the litter ...
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-1
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Mechanism for formation of both Iron (III) Oxides in rust equation?
In the equation
$4 \mathrm{Fe}^{2+}(a q)+\mathrm{O}_2(g)+(2+4 x) H_ 2 \mathrm{O} \rightarrow 2 \mathrm{Fe}_ 2 \mathrm{O}_ 3 \cdot x H_ 2 O+4 \mathrm{H}^{+}(a q)$
I'd like to know how both the Iron (...
4
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1
answer
1k
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Calculating ΔH from bomb calorimetry
Suppose we carry out a reaction in a bomb calorimeter whose starting temperature is $298.15\ \mathrm K$. Here we assume $\Delta V$ is close enough to zero that we consider the process to be at ...
CommunityBot
- 1
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Why does chlorine have a higher electron affinity value than fluorine? [duplicate]
Why does chlorine have a higher electron affinity value than fluorine? Since this periodic property tends from the bottom up (in the group), the logic would be that the fluorine is the element with ...
- 4,608
1
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1
answer
110
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Converting cif file with powdll, plotting cif file in excel
When I press convert in powdll converter software, I get this error message "Object reference not set to an instance of an object". I haven't been able to convert any kind of file type ...
- 30.3k