Equilibrium Flashcards
Reversible reactions eventually reach a state where..
energy is minimized and entropy is maximized.
How are chemical equilibria dynamic in reversible reactions?
the reaction are still occurring, just at a constant rate
Why do the concentrations of reactants and products remain constant in reversible reactions?
Because the rate of the forward reaction equals the rate of the reverse reaction.
What is the law of mass action?
gives the expression for the equilibrium constant, Keq. The reaction quotient, Q, has the same form but can be calculated at any concentrations of reactants and products. Q is a calculated value that relates the reactant and product concentration at any given time during a reaction. Keq is the ratio of products to reactants at equilibrium, with each species raise to its stoich coefficient. Keq for a reaction is constant at a constant pressure. This law only includes gases and aqueous species, no pure solids or liquids.
what does the Q and Keq comparison give?
if QKeq, ΔG>0 the reaction proceeds in the reverse reaction.
What is Le Chatelier’s principle?
states that when a chemical system experiences a stress, it will react so as to restore equilibrium.
What are the three main types of stresses applied to a system?
Changes in concentration, pressure and volume, and temperature.
What happens when you change concentration?
Increasing reactants or decreasing the products will shift the reaction to the right. Increasing the products or decreasing the reactants will shift it to the left.
What will happen if you change pressure?
increasing pressure on a gaseous system (decrease volume) will shift the reaction towards the side with fewer moles of gas. Decreasing pressure on a gaseous system (increasing volume) will shift the reaction toward the side with more moles of gas.
What happens when you change the temperature?
increasing temp of an endothermic reaction or decreasing the temp of an exothermic reaction will shift the reaction to the right. Decreasing the temp of and endothermic reaction or increasing the temp of an exothermic reaction will shift the reaction to the left.
What are kinetic products?
are highter in free energy than themodynamic products and can form at lower temperatures. These are sometimes termed fast products because they can form more quickly under certain conditions.
What are thermodynamic products?
lower in free energy than kinetic products and are therefore more stable. Despite proceeding more slowly than the kinetic pathway, the thermodynamic pathway is more spontaneous (more negative).
Equilibrium constant equation
Keq = [C]^c[D]^d/[A]^a[B]^b .
Quotient equation
Qc=[C]^c[D]^d/[A]^a[B]^b
What is static equilibrium?
forward and reverse reactions are not occurring.
