K constants Flashcards
What does Kr represent?
the k constant for the REVERSE rxn of a rxn
What is Keq a ratio of?
products:reactants (at equilibrium)
how big must a k constant (from a rate law) be in order fo the rxn to be considered fast?
10^9 or bigger
when does kc = kp?
When delta n in the kp equation = 0
The both sides of the equation have the same number of moles
What does Kf represent in a rxn rate law?
the k constant for the forward rxn of a rxn
What is Kp a ratio of?
rate of the forward reaction to the rate of the reverse reaction
(with respect to component pressures)
How large must Keq be in order for us to conclude that products in its rxn are favored?
Keq must be 1 or bigger
how SMALL must a k constant (from a rate law) be in order fo the rxn to be considered SLOW?
less than 10^9
How SMALL must Keq be in order for us to conclude that reactants in its rxn are favored?
Keq must be smaller than 1
Does large pka mean strong acidity?
No! SMALL pka means strong acidity (it’s backwards from ka)
What is Kw a ratio of?
products (H+ and OH- ions) to reactants (H2O)
OF PURE WATER
which kind of k does chpt 16 (acid base equilibrium) focus on?
ka, kb, kw
When you’re doing a weak acid/weak base problem with ICE tables, how small must the k be to support ignoring the x value in the denominator?
K must be 10E-5 or smaller
But you should still double check by???
what is keq called in words?
equilibrium constant expression
What is Ka a ratio of?
products (ions) to reactants (original acid)
Does large pkb mean strong basicity?
No! SMALL pkb means strong basicity (it’s backwards from kb)
what does the k constant in rxn rate laws represent?
rate/factor by which rxn component concentrations (or pressures) are changing AT A GIVEN TEMPERATURE
What is the number value for kw when water is at room temperature?
1.0E-14
what is kb called in words?
base-dissociation constant
which kind of k does chpt 15 (equilibrium) focus on?
the keq
can be expressed as kc or kp
how are ka and kb (mathematically) r/t kw?
what’s the math expression that relates all 3 of them?
ka * kb = kw
why are Kf and Kr important to the math about equilibrium?
When you divide Kf/Kr, you get a constants kc or kp (which we use to describe ratios between forward and reverse rxn in terms of concentration or pressure)
What is Kb a ratio of?
products (ions) to reactants (original base)
what is kw called in words?
ion product constant of water
which kind of k does chpt 14 (kinetics) focus on?
the k from the rate law expression
what is ka called in words?
acid-dissociation constant
What is Kc a ratio of?
rate of the forward reaction to the rate of the reverse reaction
(with respect to component concentrations)
