FINAL EXAM STUDY GUIDE CHEM
130
MODULE 4 (CHAPTER 8)
, FINAL EXAM STUDY GUIDE BREAKDOWN
Module 4 (Chapter 8)
1. Explain factors that determine the equilibrium conditions of a system for Le
Châtelier’s Principle
From Concept Summary:
“Factors known to influence the position of equilibrium include changes in the amount of
reactants and/or products and changes in temperature. The influence of such factors can
be predicted by using Le Châtelier’s Principle. Catalysts cannot change the position of
equilibrium.”
Factor Effect
Concentration Adding/removing reactants/products shifts the equilibrium to rebalance
Temperature Increasing/decreasing temperature affects which side (reactants/products)
is favored Pressure Only affects gases — increasing pressure shifts toward fewer gas
molecules
Example:
If you add more salt (reactant) to soup (reaction), the system shifts to balance the flavor—just
like the reaction will shift to consume what’s added.
2. For an endothermic reaction, energy is absorbed when the reaction runs in: a) Forward
direction
b) Reverse direction
From Concept Summary:
“Endothermic reactions absorb energy, and energy increases favor spontaneity.”
Explanation:
• Endothermic = takes in heat/energy
In an equation, it looks like: Reactants + heat → Products
So, in the forward direction, you’re absorbing heat, which makes the reaction endothermic.
• Answer: a) Forward Direction
Example:
Ice melting is endothermic — it absorbs heat from its surroundings to turn into liquid.
3. According to Le Châtelier’s Principle, predict the equilibrium shift for the following: A + B ⇌
C
+ D + heat
, From Concept Summary: “The position of equilibrium can shift based on changes in reactants
or products. Removing something causes the system to make more of it.”
Explanation:
• A is a reactant
• If you decrease A, the system wants to replace it
• So, the reaction will shift toward the reactants → to the left
4. Adding reactant to an equilibrium system will cause the reaction to move in a direction
to the added
reactant. From
Concept Summary:
“Adding reactants or products affects equilibrium. The system responds to reduce the change.”
Explanation:
• When you add a reactant, the system wants to use it up
• It shifts the reaction forward (to the right) to consume the extra reactant
Example:
Adding more vinegar (reactant) to baking soda speeds up the fizz (reaction goes forward).
Module 5 (Chapter 11)
5. Draw the following alkanes:
Alkyl Group Structure # of Carbon Atoms
Methyl CH₃ 1 carbon
Ethyl CH₂–CH₃ 2 carbons
Propyl CH₂–CH₂–CH₃ 3 carbons
Butyl CH₂–CH₂–CH₂–CH₃ 4 carbons
Quick Ring Name Guide:
Name Structure Type Carbons Description
Pentane Straight chain 5 C–C–C–C–C
(open) Cyclopentane Ring (cyclic) 5 5 in a ring
Hexane Straight chain 6 C–C–C–C–C–C
Cyclohexan Ring (cyclic) 6 6 in a ring
e
Heptane Straight chain 7 C–C–C–C–C–C–
C
Alkanes Drawing
130
MODULE 4 (CHAPTER 8)
, FINAL EXAM STUDY GUIDE BREAKDOWN
Module 4 (Chapter 8)
1. Explain factors that determine the equilibrium conditions of a system for Le
Châtelier’s Principle
From Concept Summary:
“Factors known to influence the position of equilibrium include changes in the amount of
reactants and/or products and changes in temperature. The influence of such factors can
be predicted by using Le Châtelier’s Principle. Catalysts cannot change the position of
equilibrium.”
Factor Effect
Concentration Adding/removing reactants/products shifts the equilibrium to rebalance
Temperature Increasing/decreasing temperature affects which side (reactants/products)
is favored Pressure Only affects gases — increasing pressure shifts toward fewer gas
molecules
Example:
If you add more salt (reactant) to soup (reaction), the system shifts to balance the flavor—just
like the reaction will shift to consume what’s added.
2. For an endothermic reaction, energy is absorbed when the reaction runs in: a) Forward
direction
b) Reverse direction
From Concept Summary:
“Endothermic reactions absorb energy, and energy increases favor spontaneity.”
Explanation:
• Endothermic = takes in heat/energy
In an equation, it looks like: Reactants + heat → Products
So, in the forward direction, you’re absorbing heat, which makes the reaction endothermic.
• Answer: a) Forward Direction
Example:
Ice melting is endothermic — it absorbs heat from its surroundings to turn into liquid.
3. According to Le Châtelier’s Principle, predict the equilibrium shift for the following: A + B ⇌
C
+ D + heat
, From Concept Summary: “The position of equilibrium can shift based on changes in reactants
or products. Removing something causes the system to make more of it.”
Explanation:
• A is a reactant
• If you decrease A, the system wants to replace it
• So, the reaction will shift toward the reactants → to the left
4. Adding reactant to an equilibrium system will cause the reaction to move in a direction
to the added
reactant. From
Concept Summary:
“Adding reactants or products affects equilibrium. The system responds to reduce the change.”
Explanation:
• When you add a reactant, the system wants to use it up
• It shifts the reaction forward (to the right) to consume the extra reactant
Example:
Adding more vinegar (reactant) to baking soda speeds up the fizz (reaction goes forward).
Module 5 (Chapter 11)
5. Draw the following alkanes:
Alkyl Group Structure # of Carbon Atoms
Methyl CH₃ 1 carbon
Ethyl CH₂–CH₃ 2 carbons
Propyl CH₂–CH₂–CH₃ 3 carbons
Butyl CH₂–CH₂–CH₂–CH₃ 4 carbons
Quick Ring Name Guide:
Name Structure Type Carbons Description
Pentane Straight chain 5 C–C–C–C–C
(open) Cyclopentane Ring (cyclic) 5 5 in a ring
Hexane Straight chain 6 C–C–C–C–C–C
Cyclohexan Ring (cyclic) 6 6 in a ring
e
Heptane Straight chain 7 C–C–C–C–C–C–
C
Alkanes Drawing
