General Chemistry Ch 6. Equilibrium

Question 1

Reversible reactions

Answer 1

Steady state in which energy is minimized in entropy is maximized, dynamic

Question 2

Dynamic

Answer 2

Reactions are still occurring, just at a constant rate

Question 3

Law of mass action

Answer 3

Gives the expression for the equilibrium constant, Keq

Question 4

Chemical equilibria

Answer 4

Dynamic, concentrations of reactants and products remain constant because the rate of the forward reaction equals the rate of the reverse reaction

Question 5

Law of mass action

Answer 5

Gives the expression for the equilibrium constant Keq, if a system is at equilibrium at a constant temperature, then…

Key = [C]^c*[D]^d/[A]^a/[B]^b

Does not include pure solids and liquids, only gases and aqueous species

Question 6

Reaction quotient

Answer 6

Q - Same form as keq but can be calculated at any concentrations at any given time during a reaction, relates the reactant and product concentrations at any given time during a reaction

Question 7

Equilibrium constant

Answer 7

Keq - ratio of products to reactants at equilibrium with each species raised to its stoichiometric coefficients, constant at a constant temperature

Question 8

Q

Answer 8

DeltaG<0 and the reaction proceeds in the forward direction

Question 9

Q=Keq

Answer 9

DeltaG=0 and the reaction is in dynamic equilibrium

Question 10

Q>Keq

Answer 10

DeltaG>0 and the reaction proceeds in the reverse direction

Question 11

Keq>1

Answer 11

The products are present in greater concentrations at equilibrium

Question 12

Keq=1

Answer 12

Products and reactants are both present at equilibrium at reasonably similar levels

Question 13

Keq<1

Answer 13

The reactants are present in greater concentration at equilibrium

Question 14

Keq«<1

Answer 14

The amount of reactants that have been converted to products can be considered negligible in comparison to the initial concentration of reactants

Question 15

Le Chateliers principle

Answer 15

States that when a chemical system experiences a stress, it will react so as to restore equilibrium

Question 16

Types of stresses applied to a system

Answer 16

Changes in concentration, pressure and volume, and temperature

Question 17

Changing concentration Le Chateliers

Answer 17

Increasing the concentration of reactants or decreasing the concentration of products will shift the reaction to the right, increasing the concentration of products or decreasing the concentration of reactants will shift the reaction to the left

Question 18

Changing pressure/volume Le Chateliers

Answer 18

Increasing pressure on a gaseous system (decreasing volume) will shift the reaction toward the side with fewer moles of gas, decreasing pressure (increasing volume) will shift the reaction toward the side with more moles of gas

Question 19

Changing temperature Le Chateliers

Answer 19

Increasing the temperature of an endothermic reaction or decreasing the temperature of a exothermic reaction will shift the reaction to the right, decreasing the temperature of an endothermic reaction or increasing the temperature of an exothermic reaction will shift the reaction to the left

Question 20

Kinetic products

Answer 20

Higher in free energy than thermodynamic products and can form at lower temperature, sometimes termed “fast” products because they can form more quickly under such conditions

Question 21

Thermodynamic products

Answer 21

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 deltaG)