All Questions
Tagged with inorganic-chemistry physical-chemistry
344
questions
2
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1
answer
110
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Why is the Molar mass of CO2 different than the weight of the sum of its particles?
The Molar mass of CO2 is stated to be 44.009 grams per mol
But in a calculation of the weight of each atom's particles((Electrons,Protons,Neutrons) times Avogadro's constant
I get 44.36 grams per mol
...
- 155
2
votes
0
answers
22
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How to Prepare Vanadium (Na3VO4) solutions buffered at pH = 7.5?
"I need to conduct adsorption studies on Vanadium using various substances like biochars and nanooxides. To prepare Vanadium solutions up to 320 ppm with a pH buffered at 7.5 using PIPES buffer, ...
- 91
2
votes
0
answers
78
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Does copper(II) hydroxide dissolve in ammonia solution?
According to University of Oregon — Chemistry Interactive Demonstrations and Educational Resources — Copper-Ammonia Complex, the equilibrium constant for the formation of copper(II) hydroxide is ...
- 620
0
votes
1
answer
68
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Do Electron-Withdrawing-Groups give an hypsochromic shift or a bathochromic one? and why?
I'm not familiar with this topic,but i know that bathochromic shifts occur when the energy gap between energy levels of the substituted molecule, are lower than the unsubstituted one;viceversa ...
- 19
0
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0
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51
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Mercury meniscus in plastic
Let's suppose you sample mercury in a polystyrene plastic test tube at 25 °C. Would it be expected that the meniscus of Hg is convex (upward curvature) ?
I assume that the only possible adhesion ...
- 9
0
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0
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30
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How does a conc. electrolyte solution extract water from a organic phase like diethyl ether or ethyl acetate?
In organic chemistry, often, during the last steps of a workup we use concentrated brine solution (NaCl) to "extract" the water from the organic layer, especially when we have an organic ...
- 51
8
votes
1
answer
1k
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Melting point of sulfur
The melting point (m.p.) of rhombic sulfur is 385.8 K while the m.p. for monoclinic sulfur is 392 K. Also, the transition temperature of rhombic to monoclinic sulfur is 369 K.
Now, consider heating ...
- 163
3
votes
0
answers
73
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Why is a C=C weaker than a C=N and even weaker than a C=O when C-C is stronger than C-N and C-O?
Why is a C=C bond weaker than a C=N and even weaker than C=O ? In terms of orbital overlap it doesn't make sense, since there is a difference in energy between the orbitals which lower the interaction ...
- 51
0
votes
1
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143
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Why is phosphoric acid a weak acid?
What is the reason for the phosphoric acid $\ce{H3PO4}$ being a weak acid despite having a structure similar to that of sulfuric acid $\ce{H2SO4}?$
I found some sources claiming that the resonance of ...
- 19
1
vote
0
answers
68
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Are there ionic compounds that dissolve in water but do not dissasociate into their ions?
I would assume such a molecule would be possible because polar ionic compounds have a partial charge that can help them dissolve in water yet not disassociate into their ion parts, but I am not sure.
- 169
9
votes
1
answer
864
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Are London dispersion forces in xenon tetrafluoride strong enough to make it a solid?
Xenon_tetrafluoride ($\ce{XeF4}$) is a well-known square-planar molecule with no dipole moment. Molecules are thus have to be bound to each other by London dispersion forces (LDF) which are known to ...
0
votes
0
answers
24
views
How to extract Copper from softgel?
I have an assignment. I need to determine the concentration of copper in a pharmaceutical product using UV-Vis spectroscopy. The product is Chophyll of Healthy America, a softgel that contains: copper ...
- 11
4
votes
0
answers
142
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Solubility or reactivity of tantalum carbide and potassium polyselenides?
It is probably an unexplored system, but is there anything known about the low temperature thermodynamic equilibrium state of this?
By 'tantalum carbide', I mean $\ce{TaC}$, and by potassium ...
- 45
2
votes
0
answers
47
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Splitting of electronic states in Tanabe-Sugano-diagrams
In Tanabe-Sugano-diagrams, different electronic transitions of term symbols of a given symmetry are shown. However, these electronic states arise due to splitting of term symbols of spherical to ...
- 383
2
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0
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35
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Question Involving Bonding (VSEPR AND VBT)
So basically any chemistry book will tell you about the extent of overlapping in different orbitals.
For formation of sigma bonds, head on overlapping happens. Chemistry textbooks always state that $p-...
- 72