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.
257
questions
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1answer
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Cation-anion radius ratio of manganese difluoride
How to determine the cation-anion radius ratio for $\ce{MnF2}?$
I tried to calculate the $r_\mathrm{c}/r_\mathrm{a}$ ratio using the relationships:
$$2r_\mathrm{c} = c$$
and
$$(2r_\mathrm{c} + 4r_\...
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0answers
25 views
Sphalerite type structure
There are binary diamond type structures for example S and Zn form sphalerite. I thought the reason this formed was because of the big difference in the radii of the atoms that allows the smaller atom ...
0
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0answers
33 views
Why do amino acids exist as zwitter ions in the solid state? [closed]
I was going through the ionization of amino acids and came across the concept of zwitterions. I assume that zwitterion existence in the aqueous state is pH driven. Pka of cooh in amino acids is ~2 and ...
0
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1answer
57 views
Is there a crystal structure of ammonia in ionic form?
Like solid $\ce{PCl5}$, does solid $\ce{NH3}$ exist as $\ce{[NH4+][NH2-]}$ (i.e. ammonium amide)?
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0answers
45 views
Why is liquid germanium denser than solid germanium?
Why are some elements like Ge and Si have liquids denser than their solids? In water it is explainable by H bonding, but no H bonds or such are there in Ge and Si.
Well, I want an explanation about ...
1
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1answer
87 views
Does a unit cell have to contain a whole number of atoms?
I was given this problem recently to compute the number of ions in a unit cell of ferrous oxide $\ce{FeO}$. The data given was:
Side length $a = \pu{5 Å}$
Density $d = \pu{4 g/cc}$
Using the ...
-4
votes
1answer
84 views
Why does Xenon Hexafluoride exist as [XeF5+][F-] and not [XeF5+][XeF2-] in the solid state [closed]
I already referred to this similar question but it yielded no explanation for the reason. Cations and anions of similar sizes stabilize each other through lattice energy effects in the solid state. ...
4
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1answer
71 views
Fractional index in a chemical formula of metal oxide
I have just read an article in which they used $\ce{WO3}$ and $\ce{WO_{2.9}}$ as precursors, whose objective was to form $\ce{WS2}$, in an atmosphere of argon by CVD. In one boat there is the powder ...
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0answers
49 views
Data-processing pipeline for protein x-ray crystallography: uncertain of terminology and order of procedures [closed]
Background: I am trying to get an overview of the data-processing pipeline for solving protein structures by x-ray crystallography, and in a very simple way understand what mathematical procedures are ...
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0answers
14 views
The Limitation of Solid Phase Peptide Synthesis In Case of Polyglycine
I was wondering if I could use your experience and all the precautions you would like to recommend for a long peptide synthesis via SPPS.
I've already got a low loading resin so this way I'll minimize ...
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2answers
105 views
How to determine the chemical state of a reactant or product in a chemical equation?
I am asked this question:
Write a balanced equation, including state symbols, for this reaction:
$\ce{calcium + hydrochloric acid -> calcium chloride + hydrogen}$
I answered this:
$\ce{...
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0answers
57 views
Violation of Fajans' rule
According to Fajans' rules, greater charge in an ionic compound results in more covalent character. But why is it that sodium oxide is more covalent than magnesium oxide? Google says boiling point of ...
3
votes
1answer
81 views
Does the Fermi level correspond to the highest occupied energy level?
I know that, in the band structure of a solid, the Fermi level is the energy level at which there is a 50% probability of finding an electron (at thermodynamic equilibrium), and that it doesn't have ...
2
votes
1answer
38 views
Is an amorphous solid a single phase?
Amorphous solid possess short-range order but no long-range order (e.g. amorphous silica, the short-range order is originated from the tetrahedral bonding between Si and O). Is it possible to have ...
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2answers
46 views
Lattice enthalpy and ionic charater
As we move down in sulphates of group 2 their solubility decreases because there is a drastic decrease in hydration enthalpy as compared to decrease in lattice enthalpy.
Does the decrease in lattice ...
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1answer
101 views
Unexpectedly low melting point of Aluminium
According to Wikipedia, the melting point of aluminium is 933.47K (660 oC) while the melting point of magnesium is 923K (650 oC), yet the melting point of sodium is merely 370.87K (98 oC).
With huge ...
2
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1answer
97 views
Why does aluminum chloride have a higher lattice energy than aluminum fluoride?
From the table below (source: McMurry's Chemistry [1, p. 212]), it is evident that $\ce{AlCl_3}$ has a higher lattice energy than $\ce{AlF3},$ even though $\ce{F}$ is smaller than $\ce{Cl}$. Why is ...
2
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1answer
81 views
Why does the colour of the same compound (e.g. magnesium nitride) differ?
When I am searching the colour of $\ce{Mg3N2}$ I came across photos showing different colours: greenish-yellow on Wikimedia,
and some other just yellow on some Google Images results.
I am eager to ...
4
votes
1answer
226 views
Structure of crystalline boron trioxide
I recently came across the statement
The structure of crystalline $\ce{B2O3}$ consists of $\ce{BO4}$ tetrahedra, two sets of which form two types of interconnected spiral chains, three $\ce{B-O}$ ...
1
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1answer
77 views
Why Frenkel defect does not impact the density of the solid?
The following text is from Chemistry Part I - Textbook for Class XII (NCERT), chapter "The Solid State", page 23, topic "1.9 Imperfections in Solids", sub topic "1.9.1 Types of Point Defects - (iii) ...
3
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3answers
195 views
Why cobalt reacts favorably with nitrogen?
I used also iron, nickel, zinc, copper. However, cobalt gives the easiest and straight forward yield of nitrides (XPS and SAED verified).
It is so easy to get cobalt nitride that I don't even have to ...
3
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1answer
74 views
Is there a “Comprehensive Solid State” book?
We have Comprehensive Coordination Chemistry, Comprehensive Organometallics, Comprehensive Organic Synthesis and probably few other similar works that aim to do a wide review of recent works at the ...
8
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2answers
515 views
Software for generating a lattice from a unit cell for molecular crystals?
I am looking for a software package which can take a unit cell (and lattice parameters, etc.) and from that generate a crystal lattice. Ideally it will have functionality for orthorhombic, hexagonal, ...
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0answers
46 views
Validity of Maxwell-Boltzmann distribution for solids [duplicate]
Suppose there is a solid made of avogadro number of, say, aluminium atoms. This solid is kept at 273 K. According to Maxwell-Boltzmann distribution, all the particles or atoms will not have the same ...
3
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0answers
118 views
Electrical and thermal conductivity of graphite
I was reading about carbon family where it was mentioned that electrical conductivity of graphite increases with temperature while thermal conductivity decreases.
However, I could not find a suitable ...
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0answers
24 views
Is silicon-oxygen bond length non-uniform in quartz glass?
In many pictures depicting the molecular structure of quartz glass(In fact, almost every picture that represents amorphous state of any solid that I have seen), the bond lengths are non-uniform (I do ...
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1answer
46 views
Do solids flow? [duplicate]
I am now confused whether solids flow or not. Some people say solidity is only a time scale notion. Some others say solids do not flow at all. While some authors say there is a threshold stress below ...
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0answers
40 views
Visualization of all hcp voids
There are 12 tetrahedral voids and 6 octahedral voids in hcp unit cell but I can't find any image that can show all tetrahedral voids and all octahedral voids in hcp unit cell (the common picture in ...
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0answers
44 views
Finding ionic radii from solubility data and density
$\pu{5.35 g}$ of a salt $\ce{ACl}$ is dissolved in $\pu{250 ml}$ of solution. The $\mathrm{pH}$ of the resultant solution was found to be $4.85.$ Find the ionic radius of $\ce{A+}$ and $\ce{Cl-}$ if ...
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0answers
67 views
Isotropic nature of Amorphous solid
Check the answer given by Divyansh Jain
I am writing this because I am not permitted to comment in that post.
Using Divyansh's idea, How can the physical properties be same in amorphous solid if ...
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vote
2answers
89 views
What's the definition of multi phase materials? Does it mean the different phases represent different materials?
I'm from a CS background and just trying to understand the real meaning behind multi phase materials. Following is the experiment which drove me towards this question.
With the help of DFT and ...
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2answers
43 views
Why the bond angles of crystalline compounds uniform while in the amorphous state the same compound has non uniform bond angles?
For example, let us take amorphous and crystalline quartz. While in crystalline quartz all bond angles are uniform, in amorphous form bond angles vary even though quartz has the same valency. Why is ...
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0answers
27 views
How do hard drives store information using magnetic layering? (Antiferromagnetic/ferromagnetic films)
I am doing some work with solid state materials in some chemistry courses and I've been doing some research into exactly how a hard drive stores information as 1's and 0's. It seems like a bunch of ...
1
vote
1answer
5k views
Contribution of Tetrahedral and Octahedral voids in HCP
I cannot find anywhere what the contribution of atoms situated at octahedral or tetrahedral voids in a HCP unit cell would be. I need to know this to be able to calculate the formula of a compound ...
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0answers
33 views
Oxidation states of Cu in YBa2Cu3O6 based on crystal structure [duplicate]
How does on go about this? I understand There is a +5 charge distributed on 3 copper ions. So either we have 2+, 2+ and 1+ or 3+, 1+, and 1+. Judging from the structure there are to unequivalent types ...
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0answers
335 views
Conversion of graphite into diamond [duplicate]
The standard state Gibbs free energies of formation of C(graphite) and C(diamond) at $T = \pu{298 K}$ are $\pu{0 kJ mol-1}$ and $\pu{2.9 kJ mol-1}$, respectively.
The conversion of graphite [C(...
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1answer
33 views
Is there any book or text where ionic radius of elements are given?
So my research has me looking for ionic radius characterization. If anyone could post any link or give the name of any book where ionic radius of all elements are given that would be really great?
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0answers
432 views
Packing fractions of HCP and FCC
The packing fractions of hexagonal close packed unit cell and face centred cubic unit cell come out to be same when calculated geometrically.
Is it just a coincidence? Differently put, could it be ...
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0answers
16 views
charge transfer between layers of graphite with stacking fault
As a general rule, we only expect two parts of a system to have the exact same amount of charge if they are symmetry-related to each other. How much charge transfer would occur in graphite with a ...
2
votes
1answer
96 views
Why does dielectric constant of crystal fluctuates in case of Frenkel defect in a crystal?
So I was studying Frenkel defect in crystal and came across this line that said
The closeness of like charges tends to increase the dielectric constant of the crystal.
I'm not able to understand ...
8
votes
2answers
281 views
Calculating the strength of an ionic bond that contains poly-atomic ions
So the bond association enthalpy for ionic compounds like $\ce{NaCl}$ and $\ce{NaBr}$ can be easily calculated from a Born-Haber cycle. But the way a Born-Haber cycle is constructed it uses info that ...
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2answers
323 views
Chemical formula of fluoroapatite
My textbook says the formula for fluoroapatite is $\ce{CaF2 * 3Ca3(PO4)2}$, whereas according to Wikipedia it's $\ce{Ca5(PO4)3F}$.
What is the correct chemical formula of fluoroapatite and why there ...
3
votes
1answer
259 views
What does x mean in (1-x)A – xB composite materials, molar ratio, weight ratio or volume fraction?
I've been collecting data about ceramic materials and often I get to see composite materials are described as $(1-x)\ce{A} - x\ce{B}$. I am confused what this $x$ means. And I haven't seen any of the ...
-2
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1answer
312 views
Is there an element with no liquid state? [closed]
I know this question might be dumb but, is there an element that will go directly from solid to gas, with almost no visible or no liquid state? Just a random curious question.
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1answer
252 views
How does lime prevent soda lime glass from dissolving in water?
How does lime addition as an ingredient prevent soda lime glass from dissolving in water? Does it form calcium silicate in the process of melting?
3
votes
1answer
182 views
Influence of the neighbouring molecules in a crystal at the example of XeF4
For reasons of symmetry I (without deeper chemical knowledge) supposed, that $\ce{XeF4}$ has a shape like $\ce{CH4}$. But according to Wikipedia its
crystalline structure was determined by both NMR ...
0
votes
2answers
393 views
Solid state and Bragg's Equation
A frst order reflection from (111) plane is observed for LiX with 2theta =24.6 degree (X-ray of wavelength 1.54 angstrom). Assuming LiX to be a cubic crystal system, calculate the length of the side ...
3
votes
3answers
291 views
How do I know crystal structures from formula?
Give an explanation why $\ce{MgF2}$ and $\ce{CaF2}$ adopt different structure types.
For example, the structure of calcium fluoride is 'fluorite' and the structure of magnesium fluoride is 'rutile'. ...
2
votes
1answer
52 views
vapor pressure of one part of binary compound
Let's say we have a binary compound AB in an enclosed container, and let's say there's a tendency to form B-vacancies so that B atoms/molecules escape and form a vapor. Let's assume there's enough of ...
7
votes
1answer
128 views
Why do we need to add hydrogen to amorphous silicon?
I was recently studying about Staebler-Wronski effect observed in amorphous silicon (a-Si). I realised it was due to imperfections in the lattice structure and breaking of Si-Si bond to Si-H bonds.
...
