U4 Flashcards
What is a solute, solvent, and solution?
Solute - What is dissolved (the substance of less quantity)
Solvent - What is doing the dissolving (substance of greater quantity)
Solution - the solute dissolved in the solvent. Homogenous.
Homogeneous vs hetergeneous mixture
Homo - Mixture of 2 or more substances. Fully mixed in any state.
Hetero - Obvious seperation in the mixture (i.e. oil and vinegar).
How do pure substances differ from solutions?
Pure substances have fixed composition (i.e. water is always H2O). Solutions are variable, different ratios.
What is concentration?
The solute to solvent or solution ratio
Concentrated vs dilute solution
Concentrated - high solute to solution ratio
Dilute - low solute to solution ratio
What is an aqueous solution (aq)?
A solution where water is the solvent
What is each type of solution (state in state), give an example of each
Solid in solid - Alloys
Solid in liquid - Sea water
Solid in gas - moth balls
Liquid in solid - Amalgam of mercury in silver
Liquid in liquid - Antifreeze in water
Liquid in gas - Water vapour
Gas in liquid - Carbonated beverages
Gas in gas - Natural gas or air
Gas in solid - !Very rare!
What affects the dissolving process?
Temperature - Hotter is faster for solid solutes (more kinetic energy)
Agitation - Stirring brings fresh solvent in contact with undissolved solid
Surface area - Smaller particle increases rate of dissolving
Why do some solutes dissolve but others don’t in certain solvents?
Attraction between solvent particles, solute particles (both need energy), and the attraction between solute and solvent particles (releases energy).
Strongly, slightly vs not polar
Strong - large electronegativity differences, assymetrical (forms ions in water)
Slight - Minor electronegativity differences, some assymetry (dissolves, but no ions)
Not - None or little electronegativity differences, symmetry (does not dissolve)
How to write a dissociation equation? What molecules can dissocosiate?
Only ionic compounds
Solid compound written on left
Water not included in equation
Eg.
K3PO4 (s) –> 3K+ + PO4-3
Define miscible and immiscible
Molecular compounds can vary in how easily they dissolve in water - miscible
Oil doesnt dissolve in water - immiscible
What does like dissolved like mean?
Polar solvents will dissolve polar solutes
Non-polar solvents will dosiolve polar solutes
They will not dissolve eachother
Define solubility
The quantity of a solute that can dissolve in a given quantity of solvent at a given temperature
How does ion charge and size affect solubility?
Ion charge and size. A small size is more insoluble because they are held tighter together. A large charge is more insoluble because it hold ions together.