Chapter 16

Question 1

Reversible reaction

Answer 1

a reaction in which not only the reactants produce the products but the products produce the react as well

Question 2

What is dynamic equilibrium? Why is it called dynamic

Answer 2

the rate forward = the rate reverse
-its called dynamic because the forward and reverse reactions are still occurring at the same rate

Question 3

Writing an equilibrium constant expression based on the concentration (Kc)

Answer 3

do not include the concentration of solids and liquid when writing equilibrium constant expression

Question 4

factor affecting equilibrium constant

Answer 4

DOES: Change in temperature
- exothermic reaction increases the temperature will decrease K and vice versa
- endothermic reaction increases the temperature will increase K and vice versa
DOES NOT: Catalyst
- does increase the rate but not the equilibrium constant
- Concentrations of solids and liquids

Question 5

aA +bB <=> cC +dD

Answer 5

[C]^c [D}^d/ [A]^a [B]^b

Question 6

The magnitude of the Equilibrium Constant

Answer 6

k «1: there will be mostly reactants and very few products at equilibrium
k&raquo_space;1: There will be mostly products present at equilibrium, The concentration limiting reaction will be almost zero
k =1: both reactant and product will be present in significant amounts at equilibrium

Question 7

Effects of Concentration Change on equilibrium

Answer 7

• increasing the concentration of reactants will cause the equilibrium to shift toward the product side
• increasing the concentration of product will cause the equilibrium to shift toward the reactant side

Question 8

Effects of volume change on equilibrium

Answer 8

the increasing volume will cause equilibrium to shift toward the side with more gaseous molecules

Question 9

Effects of Temperature Change on Equilibrium (exothermic)

Answer 9

[delta H= (-)] the plus energy is on the product side
-increasing temperature for an exothermic reaction will cause the equilibrium to shift left (toward the reactant)
- both kf and kr will increase but kr will increase to a greater extent

Question 10

Effects of Temperature change on Equilibrium (endothermic)

Answer 10

[delta H = (+)] the plus energy is on the reactant side
-increasing temperature for an endothermic will cause equilibrium to shift right (toward the product side)
- both kf and kr will increase but kf will increase to a greater extent

Question 10

what is the significance of the equilibrium constant? what does a large equilibrium constant tell us about a reaction? A small one?

Answer 10

the equilibrium constant is how the reaction proceeds one equilibrium is reached.
large - kinetically very slow and takes a while to reach equilibrium
small - reverse reaction is forward; more reactants than products at equilibrium

Question 11

What is the effect of a temperature change on a chemical reaction initially at equilibrium?

Answer 11

at initial equilibrium, temperature affects the equilibrium constant