Equilibria Flashcards
(83 cards)
True or false. at chemical equilibrium the rate of forward reaction = the rate pf reverse
True
do concentration of reaction and products stay the same at chemical equilibrium?
Yes
what does {} mean in notes
concentration
what is a species in chemistry?
reactants + products
what is a closed system in chemistry?
when none of the species (reactants or products) can escape
what is an open system in chemistary?
energy can be lost to surroundings
is equilibrium achievable outside reversible reactions?
No, it is only achievable in reversible reactions
what are the base units for concentration?
mol dm^-3
at equilibrium, it will appear as if no reaction is occurring. why?
because both the forward and reverse reactions are happening at the same rate
what is position of equilibrium
it refers to the relative amounts of reactants and products at equilibrium
what does it mean when the reverse reaction is faded (equilibrium shifts to the left)
more reactant is formed and less product (i.e., rate of reverence increases and forward decreases)
what does it mean if the forward reaction is faded (equilibrium shifts to the right)
more product is formed and less reactant (i.e. rate of forward reaction increases and reverse decrees)
what is Le Chaterlier’s Principle?
if a change is made to a system at dynamic equilibrium, the position of equilibrium moves to minimize/oppose this change
what will happen when we increase the concentration of one side of a reaction
by Le Chaterliers principle it will oppose the shift (i.e shift to the opposite side of the increased concentration)
in equation A(g) + B(g) <-> 3C(g) which side represents the lower pressure and if the pressure is increased which direction will the equilibrium shift?
reactants are 2 mols, product is 3 mols the products therefore represent the higher pressure.
if the pressure is increased by Le Chateliers principle equilibrium will shift to the left
how will the position of equilibrium change with a change in tempriture?
increasing the temp will increase the rate of both forward and reverse rxns but one rate will increase more than the other to oppose the increase
what is the effect of a catalyst on the position of equilibrium
it does not change the position of equilibrium it just allows equilibrium to be reached faster
what is the equilibrium constant
aA + bB <-> cC + dD
Kc = ([C]^c [D]^d) / ([A]^a [B]^b)
where:
Kc = the equilibrium constant
[C] = concentration of C
c = number of mols c
when can Kc be messured?
only when an equation is at equilibrium
what is partial pressure (of a gas in a mixture)?
the pressure a gas would have if it was alone in a container
what is the equilibrium constant Kp
it is the equilibrium constant calculated by pressure
why do we use equilibrium constant Kp instead of Kc
bc it is easier to find the pressure of a gas than the concentration of a gas
show in a formula the total pressure (of a mixture of gasses) is the sum of the partial pressures of a gas
P total = P A + P B + P C …
what is mole fraction?
it is the ratio of moles of gas to the total number of moles of gas present
