Solutions Equilibria Flashcards
What is dissociation?
It is when ionic solids dissociate into the ions they contain when dissolved in water.
What is precipitation?
When the free ions in the solution collide with one another it causes them to reform into the solid compound they once were
When do these solutions attain equilibrium?
When the rate at which ions dissolve is equal to the rate at which ions precipitate.
Describe saturated solutions
The solution is saturated at equilibrium
- this means it contains the maximum amount of solute that can dissolve under certain conditions
- concentration of ions remains constant
What is solubility equilibria?
The equilibrium between a solute and a solvent that occurs in a saturated solution.
What happens with covalently bonded compounds?
Solubility is based on solids dissolving in water to give the basic particles from which they are formed. So, covalently bonded structures d DISSOLVE into individual aqueous molecules rather than dissociating.
ex) sugar
C12.H22.O11 <–> C12.H22.O11
What does a solubility curve represent?
The line represents the maximum amount of solute that can be dissolved at 100g of H2O at a certain temp.
- The amount of solute in a saturated solution
Below the solubility curve represents…
unsaturated - more solute can dissolve
Above the solubility curve represents…
supersaturated - more than the usual amount of solute is dissolved - a precipitate is formed
What happens when a solution is heated?
For most substances, as temperature increases, solubility increases
exception : NH3 etc
What does concentration mean?
It refers to the amount of solute per unit volume
- express concentration as molarity (M) the number of moles of solute dissolved in one litre solution
What is the equation ratio?
Used to calculate the concentration of ions in a solution.
What is Ksp?
Stands for “solubility product”
- It is a measure of the solubility of an ionic salt
- larger the value of Ksp, larger the solubility of the salt
- can only calculate if its saturated
What is a precipitation reaction?
A reaction where two aqueous solutions are mixed together and a precipitate is produced. The solid is said to have low solubility.
Precipitation reactions & double displacement
A double displacement reaction is specifically classified as a precipitation reaction when the reaction occurs in a aqueous solution and one of the products formed is insoluble.
