CHM+130+-+Final+Exam+Study+Guide+%28Updated+3.5.2025%29 2

Module 4 (Chapter 8): Chemical Equilibrium and Le Chatelier's Principle

Factors Determining Equilibrium Conditions:
- Le Chatelier's Principle states that if a system at equilibrium is subjected to a change in concentration, temperature, volume, or pressure, the system shifts its equilibrium position to counteract the effect of the disturbance.
- Concentration: Adding a reactant or product causes the system to shift away from the added component to consume it. Removing a reactant or product causes the system to shift toward the removed component to replace it.
- Temperature:
  - In an exothermic reaction ( $\text{Heat}$ is a product), increasing temperature shifts the equilibrium to the left (toward reactants).
  - In an endothermic reaction ( $\text{Heat}$ is a reactant), increasing temperature shifts the equilibrium to the right (toward products).
- Pressure/Volume: For gaseous systems, increasing pressure (by decreasing volume) shifts the equilibrium toward the side with fewer moles of gas. Decreasing pressure shifts it toward the side with more moles of gas.
Endothermic Reaction Energetics:
- In an endothermic reaction, energy/heat is absorbed by the system from the surroundings.
- Energy is absorbed when the reaction runs in the Forward Direction ( $\text{Reactants} + \text{Heat} \rightarrow \text{Products}$ ).
Predicting Equilibrium Shifts:
- Given the reaction: $A + B \rightleftharpoons C + D + \text{Heat}$
- This is an exothermic reaction because heat is on the product side.
- Adding reactant (A or B): The reaction will move in a Forward (right) direction to consume the added reactant.
- Increasing Temperature: Shifts the equilibrium to the left.
- Adding Product (C or D): Shifts the equilibrium to the left.

Module 5 (Chapter 11): Introduction to Alkanes and Hydrocarbons

Hydrocarbon Bonding Definitions:
- Alkanes: Contain only single bonds ( $C-C$ ). They are characterized by a tetrahedral geometry around each carbon atom with bond angles of approximately $109.5^\text{o}$ .
- Alkenes: Contain at least one carbon-carbon double bond ( $C=C$ ).
- Alkynes: Contain at least one carbon-carbon triple bond ( $C \rightleftharpoons C$ ).
Saturated vs. Unsaturated Hydrocarbons:
- Saturated Hydrocarbons: Hydrocarbons that contain only single bonds between carbon atoms and have the maximum number of hydrogen atoms possible per carbon.
  - Examples: Methane ( $CH_4$ ), Ethane ( $C_2H_6$ ), Hexane ( $C_6H_{14}$ ).
- Unsaturated Hydrocarbons: Hydrocarbons that contain one or more double or triple bonds between carbon atoms, meaning they have fewer than the maximum possible number of hydrogen atoms.
  - Examples: Ethene ( $C_2H_4$ ), Ethyne ( $C_2H_2$ ), Benzene ( $C_6H_6$ ).
Boiling Points of Alkanes:
- The boiling point of alkanes increases as the number of carbon atoms (molar mass) increases due to the increase in London dispersion forces.
- Branching decreases the boiling point compared to straight-chain isomers because it reduces the surface area available for intermolecular contact.
- Ranking (Lowest to Highest BP): $a) \text{ propane} < c) \text{ butane} < b) \text{ hexane} < d) \text{ octane}$
- Highest Boiling Point: Octane ( $C_8H_{18}$ ).
Alkyl Group Structures:
- Methyl: $-CH_3$
- Ethyl: $-CH_2CH_3$
- Isopropyl: $-CH(CH_3)_2$ (a three-carbon group attached at the middle carbon).
- Sec-butyl: $-CH(CH_3)CH_2CH_3$ (a four-carbon group attached at the second carbon of the chain).

Module 5 (Chapter 12): Alkenes and Geometric Isomerism

Alkene Structures (Examples and Drawing Requirements):
- 2-pentene: A five-carbon chain with a double bond starting at the second carbon.
- 2-hexene: A six-carbon chain with a double bond starting at the second carbon.
- 3-hexene: A six-carbon chain with a double bond starting at the third carbon.
- Cis-trans Isomerism:
  - Cis-2-butene: Both methyl groups are on the same side of the double bond.
  - Trans-2-butene: The methyl groups are on opposite sides of the double bond.

Module 6 (Chapter 13): Alcohols

Distinguishing Functional Group:
- Alcohols are distinguished by the Hydroxyl group ( $-OH$ ) bonded to a saturated carbon atom.
Classification of Alcohols:
- Primary ( $1^\text{o}$ ) Alcohol: The carbon atom attached to the $-OH$ group is bonded to only one other carbon atom (or zero, in the case of methanol).
  - Example: 1-propanol.
- Secondary ( $2^\text{o}$ ) Alcohol: The carbon atom attached to the $-OH$ group is bonded to two other carbon atoms.
  - Example: 2-propanol.
- Tertiary ( $3^\text{o}$ ) Alcohol: The carbon atom attached to the $-OH$ group is bonded to three other carbon atoms.
  - Example: 2-methyl-2-propanol.
Drawing Examples:
- 2-chloro-3-hexanol: A six-carbon chain with a hydroxyl group on carbon 3 and a chlorine atom on carbon 2.
- 3-heptanol: A seven-carbon chain with a hydroxyl group on carbon 3.
- 1,3-pentanediol: A five-carbon chain with hydroxyl groups on carbons 1 and 3.
- 1,4-butanediol: A four-carbon chain with hydroxyl groups on carbons 1 and 4.

Module 6 (Chapter 14): Aldehydes and Ketones

Structural Characteristics:
- Both aldehydes and ketones contain the Carbonyl group, which consists of a carbon atom double-bonded to an oxygen atom ( $C=O$ ).
- In Aldehydes, the carbonyl group is at the end of the carbon chain (attached to at least one hydrogen).
- In Ketones, the carbonyl group is located within the carbon chain (attached to two other carbon atoms).
Boiling Point Trends (Aldehydes):
- Boiling point increases with the length of the carbon chain due to increased dispersion forces.
- Ranking (Highest to Lowest BP): $c) \text{ decanal} > b) \text{ hexanal} > a) \text{ propanal}$
Solubility Trends (Functional Groups):
- Alcohols are generally more soluble in water than ethers and alkanes because they can donate and accept hydrogen bonds.
- Ethers can only accept hydrogen bonds, making them less soluble than alcohols but more soluble than alkanes (which are nonpolar).
- Ranking (Highest to Lowest Solubility): $b) \text{ alcohols} > c) \text{ ethers} > a) \text{ alkanes}$

Module 6 (Chapter 15): Carboxylic Acids, Esters, and Ethers

Functional Group Definitions:
- Carboxylic Acid: Contains a carboxyl group ( $-COOH$ ).
- Ether: Contains an oxygen atom bonded to two alkyl or aryl groups ( $R-O-R'$ ).
- Ester: Contains a carbonyl group bonded to an ether-like oxygen ( $R-COO-R'$ ).
Boiling Point Comparison:
- Carboxylic acids have the highest boiling points among these groups because they can form stable hydrogen-bonded dimers.
- Alcohols have the next highest because they can form hydrogen bonds.
- Aldehydes are lower as they only have dipole-dipole interactions.
- Alkanes have the lowest boiling points as they only have weak London dispersion forces.
- Ranking (Highest to Lowest BP): $a) \text{ carboxylic acid} > d) \text{ alcohol} > b) \text{ aldehyde} > c) \text{ alkane}$

Module 7 (Chapter 16): Amines and Amides

Classifications of Amines:
- Primary ( $1^\text{o}$ ) Amine: Nitrogen is bonded to one alkyl group and two hydrogens ( $R-NH_2$ ).
- Secondary ( $2^\text{o}$ ) Amine: Nitrogen is bonded to two alkyl groups and one hydrogen ( $R_2NH$ ).
- Tertiary ( $3^\text{o}$ ) Amine: Nitrogen is bonded to three alkyl groups and zero hydrogens ( $R_3N$ ).
Physical Properties Comparison:
- Boiling Point: Alcohols generally have higher boiling points than amines because the $O-H$ bond is more polar than the $N-H$ bond, leading to stronger hydrogen bonding. Alkanes are lowest.
  - Ranking (Highest to Lowest BP): $b) \text{ alcohol} > a) \text{ amine} > c) \text{ alkane}$
- Solubility: Amines and alcohols can hydrogen bond with water, making them more soluble than alkanes.
  - Ranking (Highest to Lowest Solubility): $b) \text{ alcohol} > a) \text{ amine} > c) \text{ alkane}$

Module 7 (Chapter 17): Carbohydrates and Chirality

Chirality:
- Chiral Molecule: A molecule that is not superimposable on its mirror image. It usually contains at least one chiral center (a carbon atom bonded to four different groups).
- Achiral Molecule: A molecule that is superimposable on its mirror image. It typically possesses a plane of symmetry.
Carbohydrate Classification:
- Ketopentose: A 5-carbon sugar containing a ketone group.
- Aldohexose: A 6-carbon sugar containing an aldehyde group (e.g., Glucose).
- Ketotriose: A 3-carbon sugar containing a ketone group (e.g., Dihydroxyacetone).
- Aldopentose: A 5-carbon sugar containing an aldehyde group (e.g., Ribose).
Specific Carbohydrate Details:
- Glucose: Monosaccharide; primary energy source for cells.
- Maltose: Disaccharide ( $\text{glucose} + \text{glucose}$ ); found in germinating grains.
- Lactose: Disaccharide ( $\text{glucose} + \text{galactose}$ ); found in milk.
- Sucrose: Disaccharide ( $\text{glucose} + \text{fructose}$ ); table sugar.
- Cellulose: Polysaccharide; structural component of plant cell walls.
L and D Forms:
- Classification is based on the orientation of the hydroxyl ( $-OH$ ) group on the