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The Concept of Solubility - Coggle Diagram
The Concept of Solubility
Dissociation
The process of separating the positive and negative ions in solution.
Anion
Non-metal ions
Negative
Cation
Metal ions
Positive
Ionization
The process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons.
The resulting electrically charged atom or molecule is called an ion.
Ionic
An ionic bond is the attraction that occurs between ions with opposite charges
Metal and non-metal
Salts are ionic compounds
Molecular (Covalent)
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms.
Non-metal and non-metal
Do not form ions
Molecular solutes do not form ions in water
Organic compounds are molecular
Ionic compound dissolves in water
Water molecules attract and separate the anions and cations in the solute
Dissociation Equation
Balanced for both numbers of atoms and charge.
Conductivity
The ability or power to conduct or transmit heat, electricity, or sound.
Mobile and charged ions are conductive
Ionic molecules are highly conductive.
Molecular (covalent) molecules have no or low conductivity.
Electrolyte
Electrolyte solutions conduct electricity
Weak electrolyte solution = does not conduct well
Strong electrolyte solution = does conduct
Salts that dissolve well in water produce solutions with high ion concentrations, strong electrolytes
Non-electrolyte solution = does not conduct
Weak acids are weak electrolytes
Weak acids form ions, to a limited extent
Strong acids completely ionize in water
Salts
Salts differ in their abilities to dissolve in water
NaCl quite soluble in water, AgCl only slightly
All salts dissolve in water to produce electrolyte solutions
Requires the presense of ions in solution. >ions = >electrical conductivity
Units
Siemens (S)
Solubility
The maximum amount of solute that can be dissolved in a particular volume of solution at a specific temperature.
Soluble
If a substance is soluble it will dissolve in a given amount of liquid.
Different substances have different solubilities.
Solute
The substance that dissolves in a solvent (e.g. dissolves in water).
Precipitate
A precipitate is a solid that forms out of solution when it is insuluble in the solvent.
Solution
Saturated
The point where no more solute will dissolve.
Must contatin some undissolved solute
Unsaturated
A solution that contains less than the maximum amount of solute that is capable of being dissolved.
Homogeneous mixture composed of two or more substances. A solute is dissolved in a solvent. Aqueous solution is used when one of the solvents is water.
Solvent
The substance in which the solute is dissolved (e.g. water).
Usually, a solvent is a liquid. It can be a gas, solid, or supercritical fluid.
Dillution
When 2 solutions are mixed together, they dillute each other
Ions present in both solutions have a total concentration by adding them together
Calculating ion concentrations in dillution
Calculate diluted concentrations of each, recognizing the final volume of solution is the two added together
Write dissociation equations for each solution and calculate the concentration of ions in each.
Solubility of most salts increases with temperature
Units for Solubility
g/mL
ppm (parts per million)
Molarity (mol/L) = Molar solubility
g solute/100. g solvent
Converting between units
Use the molar mass to convert between grams and moles.
Equilibrium
Equilibrium exists between the undissolved solid and dissolved ions.
Solid is put on the left of the equilibrium equation (reactant).
Forward reaction rate and reverse reaction rate are equal.
Forward = dissociation/dissolving
Reverse = crystallization
Molarity
Moles of a solute per litre of a solvent
M = mol/L
Molar concentration of a solution
Calculating Molarity
Solute dissolves in water, concentration of ions proportional to concentration of solution formed.
Calculate concentration of the solution. From the dissociation equation, use mole ratio to determine the concentration of each ion in the solution.
