Chapter 13 + 16 - Equilibrium + Ksp Flashcards
What does it mean when K > 1, K < 1, and when K = 1? (ratios) What does this mean?
K>1 means that there will be many more products than reactants at equilibrium; reaction essentially goes to completion
K<1 means that there are more reactants than products at equilibrium; reaction does not occur significantly
K=1 means that the ratio of reactants to products is equal at equilibrium
Define Q
Q= the reaction quotient/”k” at a SPECIFIC TIME (best defined as reaction progress)
What does it mean when Q >k, <k, or = k?
> k system shifts left
< k system shifts right
= k system does not shift, is at equilibrium
What happens when the concentration/pressure of one or more of the products/reactants is zero?
Reaction shift towards the missing component
Homogenous vs. heterogenous equilibria
Homogenous: Same phase (ex. HCN(aq) <–> H+(aq) + CN-(aq)
Heterogeneous: Involves more than one phase
What kind of substances have no impact on the position of heterogeneous equilibrium? Why?
Pure solids and liquids due to having a constant concentration
Kc vs. Kp (not the equation)
Kc - Constant of concentrations of substances
Kp - Constant of partial pressures of concentrations
Equation relating Kc and Kp:
Kp = Kc (RT)^change in n
Reactant-favored vs. product favored (which is right, which is left?
Reactant - position lies to the left
Product - Position lies to the right
When asked for equilibrium concentration/pressure in relation to initial use a…
ICE box
When one or more concentrations/pressures are mentioned but others are not in q question, the values of the unmentioned substances are:
0
Anything divided by 0 is…
infinitely large (undefined)
In the ICE box method _______ (always/never) use coefficients to determine the concentration x values coefficients.
always
What is Ksp? How does it compare to solubility?
Ksp = solubility product
Ksp is the ratio of products:reactants at equilibrium
What is a conjugate?
Anion
Do strong acids form in solution? WHy or why not?
No, because they 100% dissociate they will never associate while in sol’n
What happens when Q>Ksp? When Q<Ksp and Q=Ksp?
Q>Ksp - Precipitation forms
Q<Ksp - No precipitation
Q=Lsp - No precipitate but maximum saturation of ions in sol’n
Pure solids/liquids _____ (do/do not appear) in the equilibrium expression
do not appear
k vs. K (AUTHORS NOTE EDIT)
k = rate constant
K = equilibrium constant, =
K or the equilibrium constant is _____-dependent. Why?
temperature, changing it will give the products and reactants new rates, and thus new concentrations at equilibrium.
What is the effect of catalysts/increasing surface area on equilibrium position?
None, they speed up rate of rxn in BOTH sides, maintaining K
Why do salts like AgCl have the same solubility in acid as they do in water?
Cl- is the conjugate of strong acid, strong acid will not form in water and instant 100% dissociate even if it did
What happens when Q (ion product) is >, <, and = Ksp? Also, what makes Q special?
Q is Ksp but w/initial concentrations
Q> Ksp = precipitation, too many reactants to dissolve
Q< Ksp = no precipitation
Q = Ksp = at equilibrium, MAXIMUM saturation b4 precipitation
Define le chatelier’s principle
a rxn at equilibrium will respond to eligible changes by increasing product or reactant reaction rates
When adding two equations the K is…
multiplied
How does changing the coefficient across a reaction change the K?
K is raised to the power of the multiplier of the equation
Common ion effect
Same ions on one side, rxn shifts away from that one side
relationship between Kc and Kp
Kp = Kc(RT)^delta n
Units for K and Q
nothing
