Second Test Flashcards
LCP-add product
Reaction should shift to consume product
LCP- add reactant
Reaction should shift to consume some of the reactant
LCP-decrease volume
Increases pressure of gasses, system will respond trying to reduce pressure, shift toward side with less moles.
LCP- increase volume
Shift toward side with more moles
LCP- increase pressure
(Like added inert gas) would cause no change
LCP-increase temperature (endothermic
Increases the equilibrium constant K, shifts toward products (shift toward the endothermic reaction)
LCP-increase temp (exothermic
K decreases, shift toward reactants (the endothermic pathway)
Le Chatelier’s Principle
Start with a reaction at equilibrium. Stress the equilibrium. The reaction will return to equilibrium so as to offset the stress.
What does boiling point depend on?
Applied pressure
Substance
Vapor pressure is a ____.
Constant for a given liquid and temp
Vapor pressure does not depend on…
Volume of the container
What determines the rate of condensation?
The gas density (determined by pressure)
What determines the rate of evaporation?
Temperature
For every temperature there’s only one ____ that will allow the rates of condensation and evaporation to be equal.
Pressure
For every pressure there’s only one ____ that will allow the rates of condensation and evaporation to be equal.
Temperature
The boiling point of a substance occurs where the vapor pressure is equal to the…
Applied pressure (or atmospheric pressure)
Higher rate of evaporation =
Vapor pressure is higher
Higher vapor pressure =
Lower boiling point
What causes a higher rate of evaporation?
Weaker IMFs
Boiling point varies with the strength of ____ in the liquid
IMFs
High BP means ____ IMFs
Strong
Low BP means _____ IMFs
Weak
Boiling point increases as we go _____ a group in the periodic table
Down
Molecules without ____ have low boiling points
Dipoles
An atom with more electrons and protons will have larger…
London dispersion forces
Hydorgen bond IMFs occur when…
The lone pairs on one molecule attract the hydrogen on another molecule
Hydrogen bonding causes ____ BP
High
Dispersion forces are greater than dipole-dipole forces when….
The two molecules are very different sizes
Dipole-dipole forces are greater than dispersion forces when…
The molecules are similar in size
Vapor pressure of solution is ____ than Pvap of pure solvent
Lower
Adding solute _____ Pvap
Decreases
Adding solute to a solvent…
Lowers rate of evaporation, which lowers rate of condensation and lowers vapor pressure
Adding solute ____ BP, by _____
Raises, lowering Pvap
The more volatile component will be more present in….
The vapor phase
Adding solute to pure solvent ____ the freezing point
Lowers
Melting ____ affected by adding a solute to solution
Is not initially
Rate of ____ is lowered when solute is added to solvent
Freezing
Rate of melting is lowered to reach equilibrium with the lowered rate of freezing by…
Lowering temperature at which the liquid melts/freezes
Q greater than K
shift toward reactants
Q less than K
shift toward products
Q=K
reaction at equilibrium
Gas to Solid
Deposition
Solid to Gas
Sublimation
Solid to Liquid
Melting (fusion)
Liquid to Solid
Freezing
Liquid to Gas
Evaporation (Vaporization)
Gas to Liquid
Condensation
Exothermic phase changes
Condensation, Freezing, Deposition
Endothermic phase changes
Evaporation, Melting, Sublimation
Henry’s Law
At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.
