Test 5 Flashcards
First law of Thermodynamics
Energy can not be created or destroyed, it can only be transferred from one form to another.
Second law of Thermodynamics
The entropy of the universe increases as a result of spontaneous processes.
Third law of Thermodynamics
The entropy of a perfect crystal at absolute zero kelvin is exactly equal to zero.
Q > Ksp
The solution is supersaturated,. The excess solid will precipitate out.
Q < Ksp
The solution is unsaturated and more of the solid ionic compound will dissolve.
Salts with these ions are always soluble
Alkali metals (K, Li, Na), NH4+ , ClO4-, NO3-
What is soluble with a few exceptions
Chlorides except with Pb Ag, Hg,
What are usually soluble
OH-, SO4 (2-), PO4(3-)
What does a smaller Ksp mean in regards to solubility?
Less Soluble (Reactants (solid) are favored)
What is the trend in entropy due to phase change?
Entropy increases as you go from solid –> liquid –> gas
What is the trend in entropy for molar mass?
Entropy increases as molar mass increases
What is the entropy trend for allotropes
More ordered allotropes have less entropy.
if DS is + and DH is - what can we say about the rxn?
Always spontaneous
if DS is - and DH is + what can we say about the rxn?
Never spontaneous
