Chemistry Lecture 23

Poison. Specifically, how to filter out an aqueous mixture by shifting the reaction towards the products or reactants through equilibrium.

What is equilibrium?

in chemical reactions, the state in which the conversion of reactants into products and the conversion of products back into reactants occur simultaneously at the same rate; state of balance

What is equilibrium constant (K)

value of the reaction quotient for a system at equilibrium

What is reaction quotient (Q)

ratio of the product of molar concentrations (or pressures) of the products to that of the reactants, each concentration (or pressure) being raised to the power equal to the coefficient in the equation.

What is K_c?

Equilibrium constant for reactions based on concentrations of reactants and products

K_P

Equilibrium constant for gas-phase reactions based on partial pressures of reactants and products

What is Le Châtelier's principle?

when a chemical system at equilibrium is disturbed, it returns to equilibrium by counteracting the disturbance

What do the square brackets stand for? 

Square brackets means it can be counted in units of concentration or molarity.

If you have a LARGE k,

product favored

If you have a SMALL K 

reactant favored

What is dynamic equilibrium?

When reactants are moving forwards and backwards and still at equilibrium, it is dynamic. Meaning it's able to move and stay at 0. This is because at any given moment, its ratio stays constant at the same values. “Because neither reaction is preferred, amounts of X and Y are holding steady over time” 

What happens when theres only reactants?

Must go forward and make more products.

What happens when theres only products? 

Must go backwards and stay reactants

reversible reaction

chemical reaction that can proceed in both the forward and reverse directions under given conditions

Stress

change to a reaction's conditions that may cause a shift in the equilibrium

Qc = ?

• Q=[C]x[D]y[A]m[B]n

• where mA+nB⇌xC+yD

Qp= ?

• QP=(PC)x(PD)y(PA)m(PB)n

• where mA+nB⇌xC+yD