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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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
25 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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1answer
193 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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22 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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1answer
191 views

Yellow Color of NaCl

My book says - "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 NaCl." My question is, how does an ...
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3answers
791 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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44 views

Stability of 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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43 views

Why is the electrical conductivity of Cu(I) better than that of magnesium? [closed]

My professor said it is because each atom has a different electron and atomic nucleus structure, so bond distance changes. But in some cases orbitals overlap which causes the band gap to disappear. My ...
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1answer
119 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
87 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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22 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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2answers
472 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
31 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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28 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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1answer
175 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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0answers
115 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
37 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
55 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
238 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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1answer
45 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
77 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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63 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 website: Since ...
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2answers
63 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
127 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 ...
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1answer
53 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
63 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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24 views

So of the different characteristics of a XRD plot, wich is most appropiate to identify and suggested one phase among others?

This is the XRD Powder plot of a sample prepared with {La, Ti, K and O}. Thanks a lot for your suggestions. So of the different characteristics of a XRD plot, which is most appropriate and suggested ...
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2answers
104 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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1answer
212 views

Rock Salt structure

Source BY looking at this structure of rock salt (NaCl) we can say that the chloride ions and the sodium ions have the same environment that is the nearby atoms position relative to that ion except ...
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3answers
76 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
189 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
126 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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109 views

What is the carbon footprint of a diamond?

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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1answer
115 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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1answer
113 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, ...
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1answer
244 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
168 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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41 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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1answer
31 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 ...
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2answers
121 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
104 views

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

The density of CuCl is given - x gm/cmm The crystal structure is assumed to be fcc. My teacher is claiming the we can apply the formula $$\rho=\frac{Z * M}{a^3 * N_0}$$ And he took M = 35.5+63.5gm = ...
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1answer
88 views

Structure of diamond

"diamond structure. Every carbon atom is bonded to four other carbon atoms forming a three-dimensional lattice of chair conformations." SENTENCE FROM A BOOK What does this mean? Where I am struck ...
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2answers
363 views

What are Lattice Points

What are lattice points exactly? And Also How many Lattice Points are there in each of the Unit Cells?
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1answer
1k views

What causes photovoltaic (solar) cells to degrade?

Photovoltaic panels can have 20 or 25 year underwritten warranties with a guaranteed remaining efficiency of 80 % of the new panel. That means, that photovoltaic panels seem to degrade somehow. Why ...
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1answer
112 views

Salts of hydronium ion

Are there any solids with hydronium ion in its crystal structure? If so, what are they? If not, why not? I understand there are hydroxide-containing solids and gels such as aluminium hydroxide but ...
6
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1answer
89 views

How does the crystal know where to stop stacking the unit cells?

I tried to make different crystals in the cubic system by stacking cubes in a 3d software. However I need to tell the software where to skip rows or stop stacking the unit cells in a specific ...
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1answer
49 views

Octahedral Voids

The total number of octahedral void(s) per atom present in a cubic closed pack structure is (a) 1 (b) 2 (c) 3 (d) 4 PS- I answered it (d) 4 but a key on internet says it is (a) 1. Please clarify ...
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1answer
205 views

About the nomenclature: manganate or manganite?

I am a bit confused about the correct name of $\mathrm{LaMnO}_3$. Is it lanthanium manganate or lanthanum manganite? I was assuming that since $\mathrm{SrTiO}_3$ is called strontium titanate, ...
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1answer
60 views

Why there exist no void with co-ordination number 5

Here oh = octahedral td = tetrahedral CN = co-ordination number My problem is that, that why it is not possible to have a void with CN ...