Questions tagged [ionic-compounds]
Compounds in which at least some of bonds have ionic character stronger than covalent or metallic. Many compounds called salts are ionic compounds but not all of them.
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What are the limitations of the Born-Lande' equation?
The Born-Lande' equation is used to theoretically calculate the lattice energy, $\Delta U$, of ionic compounds. It is often cited as such in literature,
$$\Delta U = -\frac{k_Az_1z_2Me^2}{4 \pi \...
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Why does beryllium have an exceptionally high hydration energy?
You would expect solubility of Group $2$ fluorides to increase down the group, as lattice energy plummets much more sharply than hydration energy does. For the most part, this is true: $\ce{BaF2}$ is ...
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How can I transform Thiamine sulfate to Thiamine hydrochloride?
I have got thiamine sulfate and want to have thiamine hydro chloride. Can I obtain it by dissolving thiamine sulfate in water and adding calcium chloride water solution as long as calcium sulfate will ...
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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 ...
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Gap in ionic radii
The above picture was shown in a presentation by my prof in inorganic chem as we were discussing ionic radii more in depth (all in pm). These are all isoelectronic radii. Notice the sudden leap in ...
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What type of bonding is present in lithium tetrahydridoaluminate?
I can tell that the negative ion has one bond which is a co-ordinate/dative covalent bond.
However, overall, would you say that lithium tetrahydridoaluminate (lithium aluminium hydride) is ionic? If ...
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Calculating the ionic strength of a histidine solution
I'm trying to repeat the calculation of the ionic strength of a solution containing histidine as a buffer I recently read in a paper. In their paper, the authors calculate the ionic strength of a 20 ...
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Expression comparing the Solubility of Ionic compounds
In chemical bonding, I am taught an expression that compares the Solvation Energy and the Lattice Energy of an ionic compound which is being dissolved in a polar solvent (could be water, could be ...
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why does lithium fluoride have a higher lattice energy than lithium iodide?
Based on my knowledge, lattice energy is proportional to the multiplication of the charge of the ions, divided by the sum of the radius of ions, as follows:
$$\text{Lattice energy} \propto \dfrac{q_+ \...
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Tin (II) chloride is white while tin(II) iodide is red. Why?
Tin (II) chloride is white while tin(II) iodide is red. Why?
The answer given in my book says:
Bigger anion has higher polarizability; more polarization greater is the intensity of colour(...
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Chemical bond at Aluminum / Aluminum oxide interface
I am trying to find out what chemical bond holds aluminum oxide to the aluminum on which it forms. The only information I was able to find on the internet was in a Google book which suggested that the ...
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Crown ether complex formation with cesium carbonate
I am searching for some papers which form complex between crown ether and caesium carbonate. But Most papers only use caesium carbonate as a base in the synthesis of crown ether, not ionic compound ...
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Why is the Conductivity trend same in fused and in dissolved or aqueous state of ionic compounds?
For an example if we take $\ce{KCl}$ and $\ce{NaCl}$ then I have understood the part where in aqueous state $\ce{Na+}$ becomes bigger than $\ce{K+}$ hence the conductivity reverses but in fused state ...
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What is the structure of sodium chloride in the liquid state?
I understand that sodium chloride when solid, is a lattice, so NaCl there is an empirical formula,(so, expresses that the ratio of Na to Cl is 1-1), and not a molecular formula expressing exact ...
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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 ...
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Why isn't the chemistry of a zinc-air battery (meaningfully) hindered by an activation energy barrier?
Virtually every source I've read pertaining to zinc-air batteries explain the chemistry of it either using these formulae or a simplified version of them:
$$
\begin{align}
&\text{Anode:} &\...
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Can one describe the bonding of Na to F in terms of molecular orbital theory? What about valence bond theory?
I would kindly appreciate an explanation in terms of the two accepted quantum mechanical theories -valence bond & molecular orbitals- for the electronic energy level structure in natrium fluoride $...
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Bond strength of carbon compounds
I read online that C=O is more stronger than C=N and the reason behind this was, 'Since bond between C and O is more polar hence it will have a slightly higher ionic nature than C and N. As we know ...
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A question about nicotinamide adenine dinucleotide
In the structure of NAD+, why does the nitrogen of pyridine bind covalently to the the first carbon of glucose while the anion stabilizing the nicotine amide ion is the phosphate group? In other words,...
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Comparing thermal stabilities of MgCl2 and BaCl2
I read that to compare thermal stabilities of ionic solids:
if the solid has a monoatomic anion, we compare thermal stability on the basis of lattice energy which is inversely proportional to size.
...
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How to interpret the shape in this representation of an electride?
This excellent answer describes the appearance of solvated electrons in ammonia as first a blue, and then metallic color. It is produced by dissolving sodium in ammonia at low temperature. According ...
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polar covalent bond
Please take a look at the image of polar covalent bond in the $\ce{H2O}$ molecule below. My question is given in bold type in the following discussion.
Here is my flow of thought that confused me so ...
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Which has more ionic character, LiF or K2O?
After drawing the structures of both and considering dipole moment, doesn't it seems that all K2O should have more ionic character than LiF?
My textbook says its LiF.
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Using electron affinity to calculate lattice energy
I am trying to calculate the lattice energy of $\ce{CaBr2}$, I am uncertain of how to incorporate the electron affinity value provided for $\ce{Br2}$ into my calculation.
Since electron affinity is ...
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Few basic questions about ionic bonding and batteries (lead)
I've got a few very very basic questions about ionic bonds and their role in batteries.
My assumptions (correct me if I'm wrong):
Ionic bonds occur between a metal and a non-metal (the non-metal ...
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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 ...
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Can solutions of polar covalent compounds conduct electricity?
I learned in class that solutions of polar covalent compounds are weakly conductive, while ionic solutions are strongly conductive.
But I'm getting different answers online. According to this lecture,...
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Hannay smith equation derivation
Our chemistry teacher taught us about Hannay smith equation for calculating the percent ionic character. He did not told how that equation was derived. I could not find any satisfactory result from ...
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How to change the counterion of a nucleotide salt?
I need to take the sodium nucleotide salts I have available in my lab and modify them to instead contain some more exotic counterions. Can I do this by binding my nucleotides to a strong anion ...
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Confusion related to exception in Fajan's rule (Regarding prediction in solubility of compounds in polar solvents)
My teacher taught us that higher the ionic character in a compound, higher is its solubility in polar solvents like water.
To illustrate this statement, he also gave us the following example-
LiOH< ...
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Which atom carries charge in polyatomic ions?
I have a basic confusion regarding polyatomic ions:
Is it meaningful to say "which atom" in a polyatomic ion is charged?
Consider for instance hydroxide OH$^-$:
The oxygen has greater ...
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What force causes an electron to jump from say Na to Cl?
Every explanation I can find says something like: valence electrons in metals have low ionising energies and non-metals ''want'' to complete their valence shell.
But I can't seem to get my head around ...
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How to determine the van't Hoff factor for different salts in water experimentally?
How do I experimentally determine the van't Hoff factor for different salts in water?
I'm going to dissolve each of sodium chloride, potassium chloride, and lithium chloride in $\pu{20 mL}$ of water ...
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Measurement of the lattice energy
The lattice energy of a solid ionic compound is the energy released when one mole of the solid compound is formed from its constituent gaseous ions at $\ce {298 K}$ and $\ce {1 bar}$. However, gaseous ...
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Lattice Energy of MX2 type
While finding the solution to the question that which among BaO and BaCl2 has hi that is energy I found that it was BaO whose lattice energy is high and there were explaining it just with charges. So ...
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Ionic liquids and deep eutectic solvent cation vs anion shape
If we consider an ionic liquid of a deep eutectic such as the choline chloride type DESs, why are ionic liquids (and deep eutectics) with not very symmetric cations and very symmetric anions more ...
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Where can I find a downloadable database of basic physical and chemical properties?
The web has many online databases of properties of compounds locked behind search interfaces, but I can't find anything you can actually download.
I want a corpus of data that might allow me to, say, ...
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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 ...
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Ionic compound gases
Does any molecule containing only ionic bonds exist as a gas in room temperature? In the case of carbon dioxide, it is a covalent molecule which is a gas at rtp. Does the same apply for ionic ...
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Type of reaction between metal and salt
What type of reaction is the following?
$\ce{ 10Na(l) + 2KNO3 (s) -> K2O(s) + 5Na2O(s) + N2 (g)}$
So far my best guess has been that it's a double replacement reactions with evolution of gas. Is ...
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Does the activity product decrease with increasing ionic strength?
I have a question regarding what happens to the solubility of $\ce{CaSO_4}$ or the rate that $\ce{CaSO_4}$ will dissolve when we add $\ce{NaCl}$ to the solution:
$\ce{CaSO_4}$ will dissolve into $\...
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How to clean copper(II) sulfate crystals from sulfuric acid?
I am going to prepare copper(II) sulfate by electrolysis with sulfuric acid for crystal growing.
How would I separate the copper(II) sulfate from the sulfuric acid left over from the electrolysis ...
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Does solid sodium hydroxide react with carbon dioxide and air moisture?
I heard a claim in the context of soapmaking that a stray grain of sodium hydroxide will decay into soda ash, i.e. sodium carbonate, on contact with air. This reaction happens in an aqueous solution, ...
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AlCl3, Al2O3, Al(OH)3. What is more ionic?
I tried with fajans' rules.
First I got AlCl3 and Al2O3. There, because O2- has high negative charge I decided that Al2O3 is less ionic. But my teacher told us that we can get the same thing by ...
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Data for Madelung Constants
Where can I find data for the Madelung constants for various ionic compounds? Specifically, I am looking at silicon tetrachloride, yttrium (III) chloride, zirconium (IV) oxynitrate hydrate, niobium (V)...
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Calculating ionic strength at different concentrations
Zn$^{2+}$ reacts with a molecule, B, in a solution at several different concentrations of NaCl.
Determine the charge of the biomolecule and k$_0$ (second order) (assume that Zn$^{2+}$ does not ...
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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+(...
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Determining ion charge using rate constants and ionic strength
I am given the following data:
The rate constant $k$ at $\pu{25 ^\circ C}$ in a reaction of persulfate ions and iodide ions in a water solution is assumed to vary with the total ionic strength of the ...
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Why does iodine trichloride dimerize?
In which of the dimerization process, the achievement of the octet is not the driving force
$\ce{2AlCl3 \to Al2Cl6}$
$\ce{BeCl2 \to BeCl2}$ (solid)
$\ce{2ICl3 \to I2Cl6} $
$\ce{2NO2 \to N2O4}$
...
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Why are stable ionic charges so strongly related to the group number?
Why do lighter elements have ionic charges so strongly related to the group number? For example, why does $\ce{Al}$ only show +3 ionic charge? The basic concept of stability in an ionic compound is ...
