SOLUTIONS Flashcards
Solute
Minor component dissolved in solvent
Solvent
Major component that dissolves solute
Second law of thermodynamics
States that hot things always cool unless you do something to stop them. Heat transfers from one body to another if both are different temperatures
3 types of interactions in solutions
- Solvent - solvent
- Solvent - solute
- Solute - solute
Solution forms when solvent-solute interaction is strongest
Trend with solutions
Molecules that form the same IMF will interact strongly together (like dissolves like)
To form a solution….
IMF of molecules separate then form new ones. DeltaSolventH and Delta SoluteH = Endothermic
After mixing solution…
Molecules interact with eachother and form new IMF. DeltaMixH = Exothermic
If DeltaSolnH..
- DeltaSolnH > 0 = exothermic unfavourable)
- DeltaSolnH = 0 = no heat transfer (favourable)
- DeltaSolnH < 0 = endothermic (favourable)
Heat of hydration DeltahydH
Heat released from the process of breaking apart ion-dipole interaction
DeltaSolnH for aqueous ionic compound
DeltaSolnH = DeltaHydH + DeltaLatticeH
Solubility depends on what
Temperature
Why is dissolving a solute in a solvent an equilibrium process
Initially only dissolution occurs and the rate slowly decreases. Then recrystallization occurs when ions are dissolved and rate grows = saturated when both processes are equal
Solubility of gasses
Less soluble at elevated temperatures
Henry’s constant
Sgas = KH Gas or Gas = KH Gas
- Sgas is concentration of gas
- Pgas is partial pressure of gas
1 atm is
1.013 bar
