The Equilibrium Constant

Experiments have shown that under a given set of conditions (WHAT and WHAT) a specific quantitive relationship exist between the equilibrium WHAT of the reactants and products

Experiments have shown that under a given set of conditions (P and T) a specific quantitive relationship exist between the equilibrium CONCENTRATIONS of the reactants and products

When different combinations of H2(g), I2(g) were mixed and the concentrations measured, it was discovered that WHAT was reached in all WHAT

When different combinations of H2(g), I2(g) were mixed and the concentrations measured, it was discovered that EQUILIBRIUM was reached in all CASES

What does [ ] means

concentration in mol/L

Even though the equilibrium [ ] are WHAT, the end WHAT was the same each time (within experimental error)

Even though the equilibrium [ ] are DIFFERENT, the end QUOTIENT was the same each time (within experimental error)

This led to the empirical generalization known as the WHAT which says that there is a CONSTANT WHAT between the concentration of the products and the concentration of the reactants at equilibrium

This led to the empirical generalization known as the LAW OF EQUILIBRIUM which says that there is a CONSTANT RATIO between the concentration of the products and the concentration of the reactants at equilibrium

What is the equation for this law using this reaction:

aA + bB → cC + dD

Kc = [C]^c x [D]^d / [A]^a x [B]^b

Where:

Kc = Equilibrium constant

A, B = Equilibrium concentration of reactants

C, D = Equilibrium concentration of products

a,b,c,d = Balancing coefficients

Kc is constant for a reaction at a given WHAT … if you change the WHAT Kc also CHANGES

Kc is constant for a reaction at a given TEMPERATURE … if you change the TEMPERATURE Kc also CHANGES

It is common to ignore the WHAT for Kc and list only as a numerical value (since depends on the powers of various [ ] terms)

Units

When determining Kc use only the species that are in WHAT or WHAT or unless WHAT

When determining Kc use only the species that are in GAS or AQUEOUS or unless ALL states are the SAME

The HIGHER the Kc value the greater the tendency for the reaction to favour the WHAT direction

FORWARD

If Kc is GREATER than 1, then the reaction is WHAT favoured

products

If Kc is LESS than 1, then the reaction is WHAT favoured

Reactants

Kc indicates the WHAT and not the WHAT of the reaction

Kc indicates the PERCENT REACTION and not the RATE of the reaction

Catalysts will NOT affect the [ ] at equilibrium… they only INCREASE the WHAT of reaction

RATE