Chapter 17 Notes
Reversible reaction – a chemical reaction in which the products can react to re-form the
reactants.
Chemical equilibrium – is when the rate of the forward reaction equals the rate of the reverse
reaction in a reversible reaction. At this point, the concentrations of its
products and reactants remain unchanged (but not equal amounts).
Le Châtelier’s Principle – if a change (or stress) is imposed on a system at equilibrium, the
position of the equilibrium will shift in a direction that tends to reduce
the effect of that change.
Changes imposed on a System
1. Adding a substance – causes the equilibrium to shift
the substance was
2. Removing a substance – causes the equilibrium to shift
where the substance was
from the side where
.
the side
.
3. Increasing temperature – causes the equilibrium of an endothermic reaction to shift
to the
and an exothermic reaction
to shift to the
.
4. Decreasing temperature – causes the equilibrium of an exothermic reaction to shift
to the
and an endothermic
reaction to shift to the
.
5. Increasing pressure – causes the reaction to shift
that has the
gaseous substances.
from the side
number of moles of
6. Decreasing pressure – causes the reaction to shift
has the
gaseous substances.
the side that
number of moles of
7. Increasing volume – causes the reaction to shift
has the
gaseous substances.
the side that
number of moles of
8. Decreasing volume – causes the reaction to shift
that has the
gaseous substances.
9. Catalyst –
the reaction but is
the process. It helps an equilibrium reaction
.
10. Adding an inert gas (noble gas) –
from the side
number of moles of
consumed in
the equilibrium.
Equilibrium constant (K) – is the ratio of the mathematical product of the concentrations of
substances formed at equilibrium to the mathematical product of
the concentrations of reacting substances. Each concentration is
raised to a power equal to the coefficient of that substance in the
chemical equation.
Ka – equilibrium constant for an
Kb – equilibrium constant for a
Kc – equilibrium constant for the
Ksp – equilibrium constant for the
Chemical equilibrium expression – is the equation used to calculate K.
Common ion effect – is the phenomenon in which the addition of an ion common to two
solutes brings about
.
Acid ionization constant (Ka) – is used to determine the dissociation of
.
Buffered solution – is a solution that is
to a change is pH due to the fact
that it contains a substance that can react as an acid or a base (buffer).
Hydrolysis – a reaction between water molecules and
Solubility product constant (Ksp) – is the product of the molar concentrations of the
of a substance in a saturated solution, each raised to the
that is the
of that ion in the
balanced chemical equation.
.
Heterogeneous equilibrium – is an equilibrium that contains more than
of reactants and/or products.
Homogeneous equilibrium – is an equilibrium that the states of all the reactants and products
are in the
.
Activation energy – the energy change needed for a reaction to
.