Questions tagged [solid-state-chemistry]

Study of chemical species that are in solid phase, either in cases of their properties, or about ways of synthesizing them.

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0answers
138 views

Reason for isotropy in amorphous substances

I'd be thankful if someone explains why amorphous substances are said to be isotropic and crystalline substances anisotropic
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1answer
83 views

Must compounds formed between solids be a solid as well?

My teacher gave us a long list of compounds and asked whether they are solid, liquid, or gas at room temperature and normal atmospheric pressure. I only know the more common compounds (eg. carbon ...
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2answers
581 views

How can diamond have a fixed refractive index?

I was doing a lesson on solid states. There were given two kinds of solids namely amorphous solids and crystalline solids. Some differences between these two solids were given in my book. One of the ...
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1answer
2k views

What is the oxidation mechanism of gunpowder?

I've been recently looking into fireworks and the chemistry of explosives, and I found out that, amongst others, one of the most important reactions in gunpowder ignition is the oxidation of charcoal ...
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1answer
757 views

Why is Cubic closed packing called “cubic”?

How is Cubic Closed Packing "cubic" and also how is hexagonal closed packing "hexagonal" ? I have been thinking over this since a few hours but I am unable to visualise. I understand that when ...
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5answers
11k views

Why are there only 7 types of unit cells and 14 types of Bravais lattices?

Why are there only 7 types of unit cells and 14 types of Bravais lattices? I was reading about solid-state chemistry for the first time and this limitation made no sense to me. I tried to do the ...
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1answer
1k views

Why does the dielectric constant of a solid increase due to a Frenkel defect?

In crystalline solids, an atom may be displaced from its original position in order to create a vacancy in the original location. This is referred to as a Frenkel defect. Why does this defect result ...
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2answers
4k views

Yellow color of NaCl

My book says: $\ce{NaCl}$ shows metal excess defect, which results into the formation of an F-center in the crystal. This F-center is responsible for the yellow color of $\ce{NaCl}$. How does an F-...
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1answer
1k views

Why can oxygen have a coordination number of 3 in a complex between silver and SiO2?

I am running an MD simulation of silver with $\ce{SiO2}$. Initially, my silver atom is neutral and oxygen has a coordination of 2 with silicon having a coordination of 4. After the deposition of ...
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3answers
4k views

Why is solid phase peptide synthesis limited to 70 amino acids?

I'm reading document about Solid phase protein synthesis (SPPS) from Wikipedia, and according to the document: SPPS is limited by yields, and typically peptides and proteins in the range of 70 ...
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0answers
246 views

Isolating radium oxide

Why is radium oxide yet to be isolated when a wide range of other radium (II) compounds are known ?
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1answer
3k views

What is the world's finest powder substance?

What is the world's finest powder substance that has the smallest granules but remains solid?
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2answers
311 views

Are molecular optimizations in quantum chemistry really in vacuum?

I know that Gaussian (or other quantum chemical packages) assumes the molecule is alone in vacuum, that is, the molecule doesn't interact with anything, when optimizing the molecule. But I've found ...
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107 views

Interstitial sites: edge and face sharing?

In close packed structures there is one octahedral hole per close packed atom. In a HCP unit cell these octahedra form a chain of face sharing polyhedra. Is this this universal in close packing or ...
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5k views

How does chromium help stainless steel prevent rusting?

Various sources (such as this one) say that stainless steel is stainless because a passivation layer of an oxide is formed, but I haven't found details on why chromium helps create this passivation ...
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1answer
46 views

Why so differance in alkali halide's crystal forms?

I always wonder that though Both $\ce{NaCl}$ and $\ce{CsCl}$ are alkali halides, why they adopt different crystal forms, FCC and BCC respectively? and I have a doubt about $\ce{CsCl}$ structure that ...
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43 views

Is hydrolytic polymerisation the mechanism by which the precipitate forms from the neutral complex?

From basic coordination chemistry and acid-base equilibria we understand that a metal hexa-aqua ion can be deprotonated until it's positive charge is balanced by the negative charge of the hydroxides ...
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2answers
21k views

Distance between successive tetrahedral voids in FCC

What is the distance between successive tetrahedral voids in a FCC crystal structure? The distance between a face centered atom and a tetrahedral void is $\sqrt{\frac{3a}{4}}$ if the cube's edge ...
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3answers
6k views

Is there a way to turn alcohol into a solid gel?

I'm wondering if there is a way to turn alcohol or another bacteria killing substance into a solid gel form, sort of like the gel you can use to clean a keyboard. Source: Aliexpress.com Computer ...
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1answer
78 views

Coloration of substances because of F-Centers

In case of metal deficient defects in the crystal lattice of a metal, the positive voids are filled by electrons. How does this result in the coloration of a substance? Does this condition arise ...
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1answer
852 views

Unit cell of CdCl2

I understand that $\ce{CdCl2}$ has a rhombohedral unit cell as shown in this book. However I often find it being referred to as a "CCP analogue" of $\ce{CdI2}$. Presumably it is the chlorides which ...
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1answer
5k views

Are all lattices Bravais lattices?

Can all lattices be described as one of the fourteen Bravais lattices? Is the hexagonal close packed structure also one of the fourteen Bravais lattices?
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79 views

What makes ceramic coated pans fail? Is it reversible? [closed]

If one reads reviews on ceramic glazed cookware (esp. frying pans) one pattern becomes apparent: the pan is awesome at first, nothing sticks to it, even with little to no oil. Then, after a few months ...
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1answer
427 views

Amorphous to crystalline: Opposite trend?

Well my book says that on heating- amorphous solids crystalline at some temperature. As far as I know , amorphous solids have a very disordered structure compared to crystalline solids and on further ...
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1answer
443 views

Formula of a cubic lattice

Question: In a cubic lattice of XYZ, X atoms are present at all corners except one corner which is occupied by Y atoms. Z atoms are present at face centres. What is the formula of compound? (...
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1answer
827 views

How to predict the 31P NMR spectra?

What can I predict about the $\ce{^{31}P}$ spectra of $\ce{TiP2O7}$? To get the required information about the crystal structure of the compound Here is a screenshot from the ICSD ...
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2answers
564 views

What allows all 3 states of H₂O to be present at the same time?

How is it possible for there to be a glacier floating on water but under clouds? Depending on the temperature, shouldn't there only be one state of water?
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1answer
269 views

What is the actual reason behind PCl₅ existing as an ionic solid?

Why does $\ce{PCl_5}$ exists in the solid state as $\ce{[PCl_6]^{-}[PCl_4]^{+}}$? What is the problem with it that it doesn't exist in its original form in solid state? Like why isn't it just $\ce{...
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1answer
277 views

In ionic solids such as NaCl, do the cations fill interstital holes in the cation's cubic close pack structure? [duplicate]

Are binary ionic solids like $\ce{NaCl}$ comprised of a cubic close packed structure of the anions with the cations filling interstital holes or do the cations and the anions contribute to the cubic ...
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1answer
188 views

The Verb for Polymorphism

How can you elegantly describe that a polymorphic substance changes its structure? It polymorphs It morphs It undergoes polymorphic transition It experiences a morphic change Or what ...
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1answer
379 views

Cohesive forces in solid solutions

I have searched through printed books and the Internet, but I cannot find a definitive answer on an issue that fascinates me: what forces keep the various compounds belonging to a solid solution ...
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2answers
353 views

Why does a liquids height in a Barometer depend linearly on pressure?

Here is a derivation I found relating the pressure P, gravity g, height h, and density $\rho$, of a liquid in a barometer $$ P=\frac{mg}{A}\\ V=Ah \\ P = \frac{mgh}{V}\\ \rho=\frac{m}{V}\\ P = \rho g ...
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2answers
5k views

Rock salt structure: chloride lattice or sodium lattice?

Source From this diagram of the rock salt structure ($\ce{NaCl}$) we see that both the chloride and sodium ions have the same environment. That is to say, they each have the same number of neighbours ...
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3answers
410 views

Why do molecular orbitals in solids merge to bands?

Why do molecular orbitals in solids merge to bands? For example: In silicon every atom is sp3 hybridised, but when I merge two of these orbitals then it yields a bonding and an antibonding MO. When a ...
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2answers
3k views

Why are there no cheap diamond equivalents?

We recently learned in school that diamonds sparkle as the are very optically dense, meaning that it takes longer for light to pass through them, thus meaning that the light totally internally ...
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1answer
4k views

Coordination numbers of ionic and intermetallic compunds

If $\ce{NaCl}$ crystallizes in an fcc lattice, its coordination number should be 12. Then why do we say that $\ce{NaCl}$ has a coordination number of 6? Also, if $\ce{CsCl}$ crystallizes in a simple ...
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2answers
891 views

Cocrystals vs Eutectic mixtures

I was reading around about the different solid states of materials and I got to a point where I have reached the multi-component solids. I was not able to find a major difference between the cocrystal ...
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0answers
370 views

What is the carbon footprint of a diamond? [closed]

I think it would be interesting and illuminating to calculate the carbon footprint (per carat) of diamond. The answer would undoubtedly be different for artificial (industrial grade) diamonds vs. ...
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2answers
6k views

Cubic lattice: How corner atom of a cube is shared by 8 atoms? [closed]

Each atom is at the corner of a cube and 8 cubes meet at each corner. Therefore each atom is shared by 8 cubes. But I can't imagine it in space, so please tell how I visualize it.
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370 views

How to predict the type of intrinsic defect? [closed]

Intrinsic defects occur when a pure material crystal shows either vacancy or interstitialcy. When an ionic compound has vacancy, the imbalance in charge has to be compensated with another defect. When ...
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1answer
602 views

Fractional Subscripts?

What is the physical meaning when we have an empirical formula with fractional subscripts such as $\ce{LiMn_{1-x}Fe_{x}PO4}$ $(0 \le x \le 1)$? This an example of the paper the notation above is ...
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1answer
3k views

Carburizing Calculation

The problem is stated as follows: The surface of a steel gear made of 1022 steel (0.22 wt% C) is to be gas-carburized at $927$ °C. Calculate the time necessary to increase the carbon content to 0.30 ...
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2answers
603 views

Fick's Second Law of Diffusion

In the book "Foundations of Materials Science and Engineering" (Smith and Hashemi) the following is written: For cases of non-steady state diffusion in which diffusivity is independent of time, Fick'...
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1answer
903 views

A semi-transparent material that is a solid

I am trying to find something I can get the ingredients for and make that starts out a liquid and sets into a solid. My end goal is to create a simple 8bit art figure so I want to pour it into a mold ...
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2answers
1k views

Why do different impurities create different colors in diamonds?

Traces of nitrogen make diamonds yellow while traces of boron make them blue. What accounts for the differences in color for a given element?
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70 views

Is there a compound where one element has a CCP structure with all voids occupied by others?

My Google-fu hasn't got me anywhere. All results have been quite fuzzy about it, nothing explicit.
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7answers
6k views

How to solidify sand

I'm doing a research project where we analyzing the structure of sand after a certain process. To get a better idea of the internal structure of the sand, we use different colors to visualize the ...
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1answer
69 views

How do scientists check which kind of unit cell is present in a crystal?

There are many types of unit cells like: Tetragonal Monoclinic Orthorhombic Rhombohedral Hexagonal Triclinic Cubic But how do scientists identify the type when a ...
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2answers
535 views

How do people check the type of defect in a crystal?

There are many types of defects like Vacancy Interstitial Schottky Frenkel Non-Stoichiometric Alien Impurities But given a sample, how do scientists know which kind of defect is present in it [...
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1answer
732 views

What is the length of a unit cell of CuCl assuming that it is fcc?

The density of $\ce{CuCl}$ is given – $x\ \mathrm{g/cm^3}$ The crystal structure is assumed to be fcc. My teacher is claiming the we can apply the formula $$\rho=\frac{Z \cdot M}{a^3 \cdot N_\mathrm ...