Molten Salt: Disassociation or Vibration?

In summary: DIn summary, when molten salt is heated, the ions will separate and the atoms will remain paired. There is the potential for Chlorine gas to be produced, but it is not likely at such high temperatures.
  • #1
Andronicus1717
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Generally, when you melt a salt (CaCl2 @800deg C specifically) are the ions disassociated as in a solution or is molecular vibration simply great enough to not allow the formation of intermolecular bonds and the atoms are floating around still paired? This is probably a dumb question and my overwhelming instinct is the latter, anyone care to confirm?

Also, will there be the potential for Chlorine gas to be produced to be exhumed from the molten salt, again my instinct is no, but at such high temperatures there might be the potential for the ionic bonds to be displaced in a collision and form Cl2? Enthalpy of formation of CaCl2 is -795.4 kJ/mol for a solid, I'll see if I can find it for a liquid and run the numbers for the reaction CaCl2(l) -> Ca(?) + Cl2(g). Would this reaction be accelerated if there was a galvanic cell taking place in the mix?
 
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  • #2
Most molten salt solutions conduct electricity so they exist as ions. As for producing chlorine, it is possible if the temperature is high enough.

CaCl2 + heat <--------> Ca + Cl2(g)

As shown the reaction is reversible. Just add heat to force the reaction to the right. How much heat (temperature) is the question. I do not know the decomposition temperature of CaCl2 but it can be found easily, I'm sure.
 
  • #3
This is simply molten anhydrous molten salt, so I don't think that qualifies it as a solution. It is a solvent to some solutes like CaO but that is on a minimal scale so maybe like water it is those impurities which make it an electrolyte, but as the process that I'm designing is supposed to purify the salt. Would it still be an electrolyte?

I know in the Plutonium electro-refining process they use a separate PuF4 electrolyte in the molten salt medium.

So I ask again what is the molecular nature of molten salt? Is there a dissociative rate of the ions or do they exist as free flowing CaCl2 molecules?Edit*

Molten salts conduct electricity the same way they do when they are dissolved in water; some of the salt molecules are dissociated into ions, which allows the ions to conduct electricity. The "Downs Cell" capitalizes on this conduction of electricity to produce virtually all of the metallic sodium required by industry. Electricity is run through molten sodium chloride (with a little calcium chloride salt added to lower the melting point of the sodium chloride). At one terminal chlorine gas is released (the anode) and at the other (the cathode) liquid sodium.
http://72.14.253.104/search?q=cache...Sal.html+molten+salt&hl=en&ct=clnk&cd=1&gl=us

Found this google cache with some good information and references. Now I need to try and qualify the percentage of ions floating around in the mix, any ideas?
 
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  • #4
Andronicus1717 said:
This is simply molten anhydrous molten salt, so I don't think that qualifies it as a solution. It is a solvent to some solutes like CaO but that is on a minimal scale so maybe like water it is those impurities which make it an electrolyte, but as the process that I'm designing is supposed to purify the salt. Would it still be an electrolyte?

I know in the Plutonium electro-refining process they use a separate PuF4 electrolyte in the molten salt medium.

So I ask again what is the molecular nature of molten salt? Is there a dissociative rate of the ions or do they exist as free flowing CaCl2 molecules?


Edit*

Molten salts conduct electricity the same way they do when they are dissolved in water; some of the salt molecules are dissociated into ions, which allows the ions to conduct electricity. The "Downs Cell" capitalizes on this conduction of electricity to produce virtually all of the metallic sodium required by industry. Electricity is run through molten sodium chloride (with a little calcium chloride salt added to lower the melting point of the sodium chloride). At one terminal chlorine gas is released (the anode) and at the other (the cathode) liquid sodium.
http://72.14.253.104/search?q=cache...Sal.html+molten+salt&hl=en&ct=clnk&cd=1&gl=us

Found this google cache with some good information and references. Now I need to try and qualify the percentage of ions floating around in the mix, any ideas?

If it is your intention to purify this salt by melting and applying some process to the molten salt, the molten salt does behave as a solution. It is a solution for the impurities...

At 800 C, CaCl2 probably doesn't dissociate into Cl2. The term you are looking for is "activity of molten salt solutions".

See here:

http://adsabs.harvard.edu/abs/1973iams.rept...3S
 
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FAQ: Molten Salt: Disassociation or Vibration?

1. What is molten salt and how does it disassociate or vibrate?

Molten salt refers to a type of salt that has been heated to a liquid state. When molten salt is heated, the atoms within the salt begin to move and vibrate more rapidly, causing the salt to disassociate into its individual ions.

2. What is the significance of molten salt disassociation or vibration?

Molten salt disassociation or vibration is significant because it allows for the separation and manipulation of ions within the salt, making it useful for various industrial and scientific processes such as energy storage, metal production, and chemical reactions.

3. How is molten salt disassociation or vibration achieved?

Molten salt disassociation or vibration is achieved by heating the salt to a high temperature, typically above its melting point. This causes the ions to gain enough energy to break away from each other and move independently.

4. Are there any safety concerns when working with molten salt disassociation or vibration?

Yes, there are safety concerns when working with molten salt. The high temperatures involved can cause burns, and the salt itself can be corrosive. Proper safety precautions, such as protective equipment and proper handling techniques, should always be followed when working with molten salt.

5. What are the potential applications of molten salt disassociation or vibration in the future?

Molten salt disassociation or vibration has the potential to be used in a wide range of applications, including storing and converting solar energy, producing clean fuels, and generating electricity in nuclear power plants. It also has potential uses in the field of advanced materials and chemical synthesis.

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