All Questions
Tagged with ionic-compounds crystal-structure
28
questions
4
votes
6
answers
2k
views
Does an ionic bond have a dipole?
Is an ionic compound like NaCl considered a dipole? It has a positive side (Na+) and a negative side (Cl-). Or is it true that an ionic bond does not have a dipole because a dipole is, by definition, ...
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....
0
votes
0
answers
55
views
Data for Madelung Constants
Where can I find data for the Madelung constants for various ionic compounds? Specifically, I am looking at silicon tetrachloride, yttrium (III) chloride, zirconium (IV) oxynitrate hydrate, niobium (V)...
4
votes
2
answers
555
views
Why aren't ionic crystals stronger than diamond?
If ionic bonds are stronger than covalent bonds, then why aren't ionic crystals stronger than diamond, which is bonded by covalent bonds?
Diamond has tetrahedral structure with carbons forming ...
- 59
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
4
votes
1
answer
5k
views
Finding the atomic packing factor (APF) of Sodium Chloride and other FCC ionic compounds
For a piece of coursework I am doing, I need to calculate the atomic packing factor of some ionic compounds. I have had no formal teaching in this area, so what I know comes from information I have ...
- 41
2
votes
1
answer
2k
views
Why is the ionic radius of hydride so large?
The order of ionic radii for halides and hydride is apparently as follows:
$$\ce{F-} < \ce{Cl-} < \ce{Br-} < \ce{H-} < \ce{I-}$$
Why is the hydride ion so large, even larger than bromide ...
2
votes
1
answer
559
views
Unit cell structure of ionic crystal
I have a question about the structure of an LiH unit cell, and while this is related to a homework problem, it isn't the problem itself, I'm just looking for conceptual understanding. I've already ...
- 29
5
votes
1
answer
231
views
Why don't ionic compounds show stereoisomerism?
When I was reading about crystalline nature of ionic compounds, I came across the statement that ionic compound doesn't show stereoisomerism. What does that mean and can anybody explain the reason ...
- 107
8
votes
1
answer
464
views
What would superionic water ice look like?
Phys.org's Giant lasers crystallize water with shockwaves, revealing the atomic structure of superionic ice links to
Nature Physics: Experimental evidence for superionic water ice using shock ...
- 5,900
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
2
votes
1
answer
1k
views
How to get ionic radii for coordination number 12?
I am studying $\ce{ABX3}$ perovskites, and I would like to calculate Goldschmidt tolerance factors for them. The $\ce{A}$ sites in these materials have a coordination number $12$.
The Shannon's ...
0
votes
1
answer
136
views
The Conductivity of Electrolytes based on structure of Ionic Crystal [closed]
Background
I want to run an experiment to test the conductivity of various ionic compounds dissolved in water. I was hoping to see some sort of trend in the increase/decrease of conductivity based on ...
- 57
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
1
answer
6k
views
Why is the empirical formula of sodium chloride NaCl? [duplicate]
Since we know in sodium chloride crystal sodium ions are surrounded by $6$ chloride ions and each chloride ions are again bonded to $6$ sodium ions. What I want to know is that on what basis empirical ...
- 1,005