answersLogoWhite

0


Best Answer

At saturated solution of (partly) insoluble salt (imaginable: A2B) the following Equilibrium exists:

(A2B)s --> 2A+ + B2-

The thermodynamic Equilibrium constant Ksol equals: Ksol = [A+]2*[B2-] , the square hooks symbolise the ion concentration in mole/L. Note also the power in superscript [A]power which is equal to the number of ions in the (standardised) reaction equation. Further it should be noted that the amount of solid salt (A2B)s is not in the nominator of this Equilibrium equation, Ksol = [A+]2*[B2-] and that's why it is called (Equilibrium) solubility product.

User Avatar

Wiki User

13y ago
This answer is:
User Avatar
More answers
User Avatar

Wiki User

13y ago

Solubility is normally measured as the amount of a substance that can dissolve in a solvent and is measured in units of (amount of substance)/(volume of solvent).

Barium nitrate, for example, has a solubility of 0.105 moles/litre in water, or it can also be expressed as 27.3g/litre.

The solubility product is an equilibrium constant for the process:

salt (solid) <===> cations (aq) + ions (aq)

As the activity of the solid is taken to have a value of 1, the solubility product is the result of multiplying the concentrations of the dissolved ions at the solid's maximum solubility.

The solubility product (Ksp) can be thought of as a more general expression of the solubility of a substance. To obtain the solubility product, we multiply the concentrations (mol/litre)* of ALL the ions that result from the substance dissolving when they are at their maximum concentration.

In the case of barium nitrate, we have:

Ba(NO3)2 ---> Ba2+ + NO3- + NO3-

So the solubility product , Ksp = [Ba2+][NO3-][NO3-] = [Ba2+][NO3-]2

The experimentally determined value of the solubility product for Barium Nitrate is 4.64×10-3.

For barium nitrate dissolving in pure water, [NO3-]= 2[Ba2+], so we can write

Ksp = [Ba2+][NO3-]2 = 4[Ba2+]3 = 4.64×10-3

Solving this, [Ba2+] = 0.105 mol/litre

As [Ba2+] equals the concentration of barium nitrate that is dissolved, this is the solubility of barium nitrate in pure water.

The usefulness of the solubility product is that we can use it to look at the effects of ions from other sources than the salt. For example, if we try to dissolve barium nitrate in 10 molar nitric acid, we use the same expression as before:

Ksp = [Ba2+][NO3-]2 = 4.64×10-3

But this time [NO3-] = 10 mol/litre (approx), as that is already in solution, so:

100 [Ba2+] = 4.64×10-3

[Ba2+] = 4.64×10-5

The solubility of barium nitrate in 10M nitric acid is 4.64×10-5 Mol/litre, MUCH less than its solubility in pure water, and not something that you could determine from the solubility alone.

*Strictly, we should use activity rather than concentration.

This answer is:
User Avatar

User Avatar

Wiki User

8y ago

This is product beween the ions concentration.

This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What is solubility product constant?
Write your answer...
Submit
Still have questions?
magnify glass
imp
Related questions

What is the symbol for the solubility product constant?

Ksp


What does the solubility product constant tell us about a compound?

It gives us an indication of its solubility in water. A large solubility constant (Ksp) means it is easily water-soluble. A small Ksp means it is generally insoluble in water.


What can be determined if the ion product is compared to the solubility product constant?

Whether a substance will precipitate can be determined if the ion product is compared to the solubility product constant. The value of any given equilibrium constant is accurate only at a specific temperature.


What is the relationship between solubility and solubility product constant?

Solubility Product Constant, Ksp is the equilibrium constant for a solid substance dissolving in an aqueous solution. Molar solubility is the number of moles of a substance (the solute) that can be dissolved per liter.MnAm&hArr;nMm++mAn-Ksp = [Mm+]n[An-]m


How does hot distilled water affect solubility product constant?

The solubility product increases with temperature for endothermic dissolving processes.


Why doesn't table salt have a solubility product constant?

NaCl dissolve so easily that it is not even given a solubility product constant, as this value ( also known as the Ksp) tells us the solubility for compounds that don't readily dissolve.


What is the solubility product constant k?

For a compound AB it is the result of the product [A].[B] in solution.


An equilibrium constant for the dissolving of a sparingly soluble ionic compound in water...?

solubility product constant.


What does a low solubility product constant indicate about a compound?

It does not dissolve readily.


What is the purpose of a precipitation titration?

To determine the equilibrium constant or the solubility product of a compound.


Why does a precipitate form when HCl is added to a saturated solution of NaCl?

The constant solubility product is modified.


Why potassium chromate is more soluble than silver chloride?

due to the solubility product constant(ksp)