Solutions and Solubility (5/10) Flashcards
Solution definition
A homogeneous mixture
- mixture: two substances
- Homogeneous: evenly distributed
- Heterogeneous: not evenly distributed (like a salad)
Dissoultion
Minority component (solute) reacts with solvent (majority component)
Dissolving
Like dissolves like
-polar amino acids dissolve most readily in polar solvents (like water)
Saturation
extent which solute is dissolved in solvent
-adding more solute than what solvent can handle to dissolve will precipitate
Supersaturation
Solute concentration>solute solubility
must heat and cool slowly to keep all dissolved. If not, crystallized
Electrolyte
Ions conduct electricity in a solution
higher temperature for solids
higher solubility in endothermic reactions
Higher temperature for gases
lowers solubility for gases
Solubility rules: alkali metals
All soluble in water
Solubility rules: Nitrates
All soluble in water
Solubility rules: Halides
soluble in water except when combined with silver, lead, or mercury
Solubility rules: Sulfates
Souble in water except when combined with calcium, silver, lead, etc
Solubility rules: Carbonate, phosphate, sulfide
Insoluble except when combined with sodium carbonate or ammonium phosphate
Solubility rules: Hydroxides and metal oxides
Insoluble except if combined with alkali metals
Molarity
moles of solute/Liters of solution
Molality
Moles of solute/Kg of solvent
High concentration of solute
Impacts volume
Molarity does not equal molality
Colligative properties
Properties changing solely with the concentration of solute in solution
Normality
Equivalents of solute/ Liters of solution
Calculating normality
(molarity of acid) x (acidic protons per molecule)
molarity of base) x (hydroxide ions per molecule
Solubility equilibria
balance between reactant and balanced species
Ksp expression
Product ions only
high value = large concentration of dissolved ions (high solubility)
Insolubility
No compound is truly insoluble
Molar solubility
Ksp/[cation] = [anion]
number of moles that need to dissolved for the solution to be saturated
A saturated aqueous solution when at equilibrium is…
The rates of dissolution and precipitation are equal
Common ion effect
solubility of an ionic species decreases when one of its component ions is already present in solution
Example of the common ion effect
AgCl –> Ag+ + Cl-
external Cl- is the common ion which moves closer to saturation before Ag+ can dissolve because it takes up solvent so we decrease the solubility of Ag
Coordination complex
complex ion
takes external ions and adds them to something else to allow reactants to dissolve better
