All Questions
Tagged with ionic-compounds solid-state-chemistry
15
questions
4
votes
1
answer
257
views
How to Derive the Born-Mayer Equation?
Born-Mayer Equation: $E_{P,min}=-A\frac{N_A|z_1z_2|e^2}{4\pi\varepsilon_0d}(1-\frac{d^*}{d})$
Here is where I have gotten:
$$
E_P=-A\frac{N_A|z_1z_2|e^2}{4\pi\varepsilon_0d}, E_P^*=N_AC'e^{-d/d^*}\\
$$...
- 128
5
votes
3
answers
279
views
Does chromium chromate — Cr₂(CrO₄)₃ — exist?
Is it possible to synthesise chromium(III) chromate/dichromate? The intended formulas are $\ce{Cr2(CrO4)3}$ and $\ce{Cr2(Cr2O7)3}$ and they feature both trivalent and hexavalent chromium. However, ...
user144956
4
votes
0
answers
316
views
Chemistry of Rutile, CdCl2 and CdI2
During lectures, we were told that 3d transition metal fluorides generally prefer a rutile structure. Chlorides prefer a $\ce{CdCl2}$ structure where $\ce{Cl-}$ adopt a CCP lattice and the metal ...
- 323
4
votes
1
answer
669
views
Why does KCl have FCC structure instead of BCC?
I have this table here.
\begin{array} {|r|r|}\hline \text{Radius Ratio} & \text{Coordination number} & \text{Type of Void} \\ \hline <0.155 & 2 & \text{Linear} \\ \hline 0.155-0....
-1
votes
1
answer
458
views
Balancing a chemical reaction with oxidation numbers
We have been teached how to balance chemical reactions with oxidation numbers in school, but somehow I can't understand it.
This is the equation to balance
$$\ce{Cu(s) + NO3−(aq) + H+(aq) -> Cu^2+(...
- 7
3
votes
1
answer
389
views
On the exact definitions of Frenkel and Schottky defects
The wiki page on vacancy defects says;
It is also known as a Schottky defect, although in ionic crystals the concepts are not identical.
As far as I'm aware, they're the same. Furthermore, the wiki ...
- 1,134
2
votes
1
answer
4k
views
Why does aluminum chloride have a higher lattice energy than aluminum fluoride?
From the table below (source: McMurry's Chemistry [1, p. 212]), it is evident that $\ce{AlCl_3}$ has a higher lattice energy than $\ce{AlF3},$ even though $\ce{F}$ is smaller than $\ce{Cl}$. Why is ...
- 2,109
8
votes
2
answers
665
views
Calculating the strength of an ionic bond that contains poly-atomic ions
So the bond association enthalpy for ionic compounds like $\ce{NaCl}$ and $\ce{NaBr}$ can be easily calculated from a Born-Haber cycle. But the way a Born-Haber cycle is constructed it uses info that ...
- 685
1
vote
1
answer
5k
views
Comparing the Lattice energy of different compounds
I am confused about some concepts related to Lattice energy.
First of all,how to compare lattice energy between $2$ compounds belonging to different groups and periods?
1.Between $\ce{AlF3}$ and $\...
- 113
0
votes
0
answers
820
views
To what extent are the radius ratio rules valid for predicting the crystal structure of an ionic compound?
The ionic radii of $\ce{Ba^2+}$ and $\ce{O^2-}$ in barium oxide are $\pu{135pm}$ and $\pu{140pm}$, respectively. The ratio of the radius of $\ce{Ba^2+}$ to $\ce{O^2-}$ is approximately $0.964$.
...
- 853
1
vote
0
answers
482
views
Substituting Ulexite
I'm working on ceramic glaze chemistry. One ingredient I don't have, but want to substitute is ulexite:
$$\ce{NaCaB5O6(OH)6.5H2O}$$
I have borax, calcium borate, and calcium silicate:
$$\ce{NaB4O7 ...
- 1,167
4
votes
1
answer
477
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 ...
3
votes
2
answers
6k
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 ...
- 1,796
23
votes
6
answers
5k
views
Are there any ionic amorphous solids?
This question on NaCl crystalization actually got me wondering: are there any ionic amorphous solids? Like ionic crystals are crystalline materials of electrostatically-attracted ions, can ions form ...
- 23.8k
24
votes
4
answers
5k
views
How does NaCl maintain its crystalline structure?
My understanding is that $\mathrm{NaCl}$ is an ionic compound, in which $\mathrm{Cl}$ becomes (effectively) $\mathrm{Cl^-}$ and $\mathrm{Na}$ becomes $\mathrm{Na^+}$. So I understand why I would get a ...
- 563