Solubility and the Ksp Flashcards
❑ Salts dissolve more readily in solvents with electrostatic dipoles like water.
Solvation
What happens when solid salt break apart?
❑ Ionic compounds exist as ___ and not as molecules
❑ These ions are held in place by strong ________ attraction in their lattice structure.
❑ To break them apart, it requires an energy ( __________) equivalent to their attractive forces ( _________), bringing these ions into solution.
❑ These two energies are opposing and compete with each other, thus telling whether a salt forms ions effectively in solution or not.
❑ For a substance to be readily soluble, the solvation energy must be _______ in magnitude than lattice energy.
ions
electrostatic
solvation energy/ lattice energy
greater
❑ In order for NaCl to be soluble, the Na+ and Cl- ions must break free from the crystal-lattice structure of the solid.
❑ When the ions are in solution, they are surrounded by water molecules, and the ions are said to be _______.
solvated
H2O is a _____ molecule
polar
molecule has negatively and positively charged regions.
polar molecule
When several ______ molecules surround an ion in the crystal, the sum of the attractive forces between the water molecules and the ion may become strong enough to overcome the attractive forces between the cations and anions in the crystal
water
The ____________ of difficulty soluble salts are comparatively larger than their energies of solvation.
They produce only few ions in solution, thus making the reaction reversible.
In a saturated solution, an equilibrium is established between ions in solution and undissolved solutes
lattice energies
What happens to slightly/sparingly soluble salts in the solution?
❑ The equilibrium exist between ions detaching from the crystals and ions depositing back to the crystal salt.
❑ The solution is said to be _____ at this point
saturated
The ________________ is the amount of that substance that will dissolve in a given amount of solvent usually expressed in grams/Liter or g/100mL
solubility of a substance
❑ Although most compounds dissolve in water to some extent, many are so slightly soluble that they are called “ ______________.”
insoluble compounds
❑ As a rule of thumb, compounds that dissolve in water to the extent of _____________ or more are classified as soluble (Molar Solubility).
0.020 mole/liter
“________” may be considered to be in equilibrium; the equilibrium is between solid and ions in solution.
Solubility
Any ionic solid is ____% ionized in an aqueous solution; once it actually dissolves.
100%
❖ The greater the Ksp the more _________ the solid is in H2O.
soluble
Large value of Ksp means a substance is soluble in water. (______)
> 10-2
