7.1 to 7.3

Equilibrium

A state in a reversible reaction where the rates of the forward and reverse processes are equal, resulting in no net observable change.

Dynamic Equilibrium

A condition in a reversible reaction where reactants and products are continually interconverting at equal rates but their concentrations remain constant.

Reversible Reaction

A reaction that can occur in both forward and reverse directions, often represented with a two-way arrow. Sometimes proceeds in each direction simultaneously.

All reactants are NOT consumed

Evaporation & Condensation of Water: H2O ←→H2O (g)

Dissolving & Precipitating a Salt: NaCl (s) ← →NaCl (aq)

Absorption & Desorption of a Gas: CO2 (g)← →CO2 (aq)

Reversible Redox reactions(transfer of electrons)

Discharging and recharging a lead-acid battery

Pb + PbO2 + 2 H2SO4← →2 PbSO4 + 2 H2O + electrical energy

Reversible Acid-Base Reactions(Transfer of protons)

Acetic Acid and Water in Vinegar

CH3COOH (aq) + H2O (← →) CH3COO- (aq) + H3O+ (aq)

Characteristic of reversible reactions(Proceeding to the right v. Proceeding to the left)

When the rate of the forward reaction is greater than the rate of the reverse

reaction, there is a net conversion of reactants into products

The reversible reaction is proceeding to the right

When the rate of the reverse reaction is greater than the rate of the forward

reaction, there is a net conversion of products into reactants

The reversible reaction is proceeding to the left

Completion Reaction

A reaction in which all reactants are consumed to form products, represented with a one-way arrow. Usually involve the production of water, gas, or a precipitate.

ex: CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g)

Reaction Quotient (Qc)

A measure of the relative concentrations of products and reactants at any point in time.

Equilibrium Expression

A mathematical expression that relates the concentrations of the products and reactants at equilibrium.

Equilibrium Constant (Kc)

A constant value that describes the ratio of the concentrations of products to reactants at equilibrium for a given reaction.

Kp

The equilibrium constant for gas-phase reactions measured in partial pressures.

Dimerization

A chemical reaction where two molecules combine to form a larger molecule, known as a dimer.

Closed System

A condition where neither reactants nor products can enter or leave, allowing for equilibrium to be established.

No Net Change

A situation at equilibrium where concentrations of reactants and products no longer change.

Forward Reaction

The reaction progress where reactants are converted into products.

Reverse Reaction

The process in a reversible reaction where products are converted back into reactants.