Crystals of high ionic charge are less soluble. why?

In summary, high ionic charges are less soluble because they have less hydration energy, which is due to the competition between the lattice energy and the solvation energy.
  • #1
gracy
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Crystals of high ionic charge are less soluble. why?As we know,when hydration energy is less than lattice energy the ions are not soluble.
So,crystals of high ionic charges have less hydration energy right?And it does make sense to me as higher the charge ,greater the lattice energy because lattice energy is proportional to charge.And higher the charge ,easier to form bond with water so greater is extent of solvation so less energy required for hydration,hence less hydration energy.
Thus,overall the criteria to be less soluble is
fulfilled i.e lattice energy is greater than hydration energy.

Is my reasoning correct?
 
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  • #3
Simon Bridge said:
Well done:
Thanks for boosting me.It really means a lot to me.
 
  • #4
No worries - It's good to see people using their wits :)
The link I gave you makes a more complete case though... do read: it should deepen your understanding.

Aside: when typing, always put a space character, " ", after sentence punctuation characters - that's ", ; : . ? !" you get the idea.
Compare what I've just written with your post #1 to see what I mean... I put a space after commas and periods etc. It makes your typing easier to read, and makes your output look more "pro", but is otherwise no biggie.
 
  • #5
gracy said:
And higher the charge ,easier to form bond with water so greater is extent of solvation so less energy required for hydration,hence less hydration energy.
Er, no, the last conclusion is not correct, or only formally so, as hydration energy is negative, and will become more negative with increasing charge. However, you have to note that this will tend to stabilize the solution. So the lattice energy and the solvation energy are really competing, and you have to discuss more closely their relative size.
One point is that in lattices made up from highly charged species, the lattice energy will go up like the product of the individual charge of the ions (e.g. 2x2 for MgO or 3x2 for Al2O3) while the interaction energy between an ion and the hydration sphere will be more linear in charge, i.e. does not increase as fast. Ions of higher charge n will also have less hydration entropy as compared to n singly charged ions.
 
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Likes gracy

1. Why are crystals of high ionic charge less soluble?

Crystals of high ionic charge contain ions with a strong attraction to each other, making it difficult for them to separate and dissolve in a solvent. This results in lower solubility compared to crystals with lower ionic charge.

2. How does high ionic charge affect solubility?

The higher the ionic charge of a crystal, the stronger the electrostatic forces between its ions. These forces make it more difficult for the ions to break apart and dissolve in a solvent, resulting in lower solubility.

3. Are there any exceptions to the rule that high ionic charge crystals are less soluble?

Yes, there are exceptions to this rule. For example, some crystals with high ionic charge may have a more complex crystal structure, allowing for more space between ions and thus making them more soluble. Additionally, the presence of certain solvents or chemical additives can also affect the solubility of high ionic charge crystals.

4. Can the solubility of high ionic charge crystals be increased?

Yes, the solubility of high ionic charge crystals can be increased by changing the conditions of the solution, such as increasing the temperature or changing the pH. Additionally, using a different solvent or adding a solubilizing agent can also help increase their solubility.

5. How does the solubility of high ionic charge crystals affect their use in various industries?

The lower solubility of high ionic charge crystals can make them less desirable for use in certain industries, such as pharmaceuticals, where solubility is important for drug delivery. However, they may be more useful in industries where low solubility is desired, such as in the production of coatings or pigments.

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