SCH4U1 Chemistry Exam Review PDF

SCH4U1 - Chemistry Exam Review Unit 1: Organic Chemistry 1.​ Identify and name Structural Isomers. Structural isomers are compounds that have the same chemical formula but différent structure. An example of this can be Hexane (C6H10) and 2-Methylpentane. 2.​ Identify major functional groups...

SCH4U1 - Chemistry Exam Review Unit 1: Organic Chemistry 1.​ Identify and name Structural Isomers. Structural isomers are compounds that have the same chemical formula but différent structure. An example of this can be Hexane (C6H10) and 2-Methylpentane. 2.​ Identify major functional groups found in organic compounds. ​ Alcohols - All contain a hydroxyl (OH) group bonded to a carbon (ex. Ethanol, CH3CH2OH) ​ Aldehyde - All contain a carbonyl group (carbon double bonded to an oxygen) connected to two R groups. ​ Ketone - All contain a carbonyl group (carbon double bonded to an oxygen) connected to one R group and hydrogen. ​ Carboxylic Acid - All contain a (COOH) group. An example of this is Acetic Acid (CH3COOH) ​ Esters - All contain a (-COO-) group. An example of this is Ethyl Acetate. (CH3COOCH2CH3) ​ Amines - All contain an (NH2) group. An example of this is Methyl Amine (CH3NH2) ​ Amide - All contain a (-CONH2) group. An example of this is Acetamide (CH3CONH2)  ​ Alkenes - Two carbons double bonded together. ​ Alkynes - Two carbons triple bonded together. ​ Ether - All contain an (R-O-R) group, an oxygen bonded in between two carbon atoms. ​ Halide - All contain a halogen in its structure (i.e: F, Cl, Br, I) ​ Thiols - All contain a sulfur bonded to a hydrogen group. (ex. Methanethiol - CH3SH) ​ Phenol - A hydroxyl group attached to an aromatic/benzene ring 3.​ Determine the products of oxidation, addition and substitution reactions involving organic compounds OXIDATION REACTIONS: ​ Primary Alcohols - When oxidized, turn into an Aldehyde. ​ Secondary Alcohols - When oxidized, turn into a Ketone. ​ Tertiary Alcohols - Do not undergo oxidation, no reaction occurs. ​ Aldehydes - When oxidized, turn into a Carboxylic Acid. ADDITION REACTIONS: ​ Hydrogenation: Alkenes and Alkynes undergo the addition of H2 to become Alkanes. For example: Ethene (CH₂=CH₂) + H₂ → Ethane (CH₃CH₃) Ethyne (C₂H₂) + H₂ → Ethane (C₂H₆) ​ Hydration: Alkenes can undergo hydration in the presence of an acid catalyst (H₂SO₄), resulting in the formation of alcohols. For Example: Ethene (CH₂=CH₂) + H₂O → Ethanol (CH₃CH₂OH) ​ Halogenation: Alkenes react with Halogens (i.e: Cl or Br) to form Dihalides (THIS IS ONLY DONE UNDER UV LIGHT OR HEAT). For example:  Propene (CH₃CH=CH₂) + HCl → 1-Chloropropane (CH₃CH₂CH₂Cl) ​ Hydrohalogenation: Alkenes react with hydrogen halides (i.e: Cl or Br) to form Alkyl Halides. For example: Propene (CH₃CH=CH₂) + HCl → 1-Chloropropane (CH₃CH₂CH₂Cl) SUBSTITUTION REACTIONS: ​ Nucleophilic Substitution - Alkyl Halides (R–X) undergo nucleophilic substitution reactions, where the halide (X) is replaced by a nucleophile (such as OH⁻, CN⁻, or an amine). For example: Methyl chloride (CH₃Cl) + OH⁻ → Methanol (CH₃OH) + Cl⁻ ​ Electrophilic Substitution - Involves the replacement of a hydrogen atom in an aromatic with an electrophile. Summary Table: Compound Functional Example Structure Type Group Amines -NH₂ Methylamine (CH₃NH₂) CH₃-NH₂ Amides -CONH₂ Acetamide (CH₃CONH₂) CH₃-C-NH₂ Ketones -C=O Acetone (CH₃COCH₃) CH₃-C-CH₃ Aromatics Benzene ring Benzene (C₆H₆) C₆H₆ (C₆H₆) Esters -COO- Ethyl Acetate CH₃-C-O-CH₂C (CH₃COOCH₂CH₃) H₃ Aldehydes -CHO Formaldehyde (CH₂O) CH₂=O Alcohols/Diol -OH Ethanol (CH₃CH₂OH), CH₃-CH₂OH, s Ethylene Glycol CH₂OH-CH₂OH (CH₂OH-CH₂OH) Carboxylic -COOH Acetic Acid (CH₃COOH) CH₃-C-OH Acids (i) POLYMER → a molecule of large molar mass that consists of many repeating subunits called monomers. (ii) MONOMER → A molecule of relatively low molar mass is linked with other similar molecules to form a polymer. (iii) POLYMERIZATION → The process of linking monomer units into a polymer. (iv) ADDITION POLYMER → A polymer formed when monomer units are linked through addition reactions. DIFFERENCES BETWEEN CONDENSATION AND ADDITION POLYMERS: ​ Addition Polymers are formed from one type of monomer with double bonds, no by-products are produced. (Ex: Polyethylene) ​ Condensation Polymers are formed from one or two different monomers, byproducts like alcohol or water are eliminated during polymerization. Unit 2: Atomic Structure & Chemical Bonding Electron Configurations (NEUTRAL + CATION) for Copper and Chromium: *Cu [Ar] 4s1 3d10 Cu2 [Ar] 3d9 + *Cr [Ar] 4s1 3d5 Cr3 [Ar] 3d3 + TYPES OF INTERMOLECULAR FORCES: London Dispersion/Van der Waals Forces: ​ Weakest intermolecular force, present in all molecules. All non-polar molecules have this force. ​ Stronger in molecules with larger sizes. Dipole-Dipole Forces: ​ Stronger than London Dispersion forces. ​ Occur only in polar molecules, where the positive end of one molecule is attracted to the negative end of another. Hydrogen Bonds: ​ The strongest intermolecular force and only occurs in molecules that contain F, O or N bonded to a Hydrogen atom. HOW TO IDENTIFY INTERMOLECULAR BONDS: 1.​ Nonpolar Molecule: Dispersion forces (London dispersion) are always present. 2.​ Polar Molecule: In addition to dispersion forces, dipole-dipole interactions will occur. 3.​ Molecule with O-H, N-H, or F-H bonds: If hydrogen is bonded to oxygen, nitrogen, or fluorine, hydrogen bonding will be present. HOW TO DETERMINE POLARITY: Molecular Geometry - If the shape of the molecule is symmetrical and the atoms have similar electronegativities, the molecule is nonpolar. If the shape is asymmetrical and the atoms involved have different electronegativities, the molecule is polar. Electronegativity Difference: A molecule will have a polar bond if there’s a significant difference in electronegativity between the two atoms (usually > 0.5). Ionic: >2.0 Polar Covalent: 0.5< E < 2.0 Covalent: < 0.5 TYPES OF MOLECULES Nonpolar Molecules: ​ Molecules with no net dipole moment due to their symmetrical geometry or equal sharing of electrons. Example: O₂, CH₄, CO₂ (linear and symmetrical). Polar Molecules: ​ Molecules with asymmetrical geometry and a net dipole moment. Example: H₂O, NH₃, HCl. *MOLECULES WITH HIGHER IMFS HAVE HIGHER BOILING POINTS Properties: ​ Boiling Point: Molecules with stronger IMFs (like hydrogen bonding or ionic bonds) have higher boiling points. ​ Solubility: Polar molecules and those capable of hydrogen bonding tend to be more soluble in water than nonpolar molecules.  ​ Acidity/Basicity: Carboxylic acids are acidic, while amines are basic. Other groups like alcohols and aldehydes show moderate behaviors. * The Quantum Mechanical Model of the atom differs from earlier models, like the Bohr model and Rutherford model, by describing electrons not as particles in fixed orbits, but as existing in probability clouds or orbitals, where their positions are uncertain. ​ Unlike the Bohr model, which only worked for hydrogen and pictured electrons moving in specific, circular orbits, the quantum model treats electrons as having both wave-like and particle-like properties. It uses quantum numbers to describe their energy levels and positions. ​ Introduces the Heisenberg Uncertainty Principle, which says you can't know both an electron's position and momentum exactly at the same time. This model explains the behavior of all atoms, including more complex ones, and provides a more accurate and detailed understanding of atomic structure. Summary Table of VSEPR Shapes: Electron Pairs Molecular Shape Bond Example Angles 2 Linear 180° CO₂, BeCl₂ 3 Trigonal Planar 120° BF₃, AlCl₃ 4 Tetrahedral 109.5° CH₄, SiCl₄ 5 Trigonal 90°, 120°, PCl₅, SF₄ Bipyramidal 180° 6 Octahedral 90°, 180° SF₆, MoCl₆ 3 (bonding), 1 Bent (Angular) < 120° H₂O (lone) 4 (bonding), 1 Trigonal < 109.5° NH₃ (lone) Pyramidal 3 (bonding), 2 T-Shaped 90°, 180° ClF₃ (lone) 5 (bonding), 1 Square Pyramidal 90°, 180° BrF₅ (lone) 4 (bonding), 2 Square Planar 90°, 180° XeF₄ (lone) Unit 3: Kinetics (Important concepts, mainly practice questions are to be done.) Temperature: For exothermic reactions, raising the temperature decreases K, while for endothermic reactions, it increases K. Stress (concentration, pressure, or temperature changes): The system shifts to minimize the disturbance, either toward reactants or products, depending on the nature of the change. Catalysts are substances that speed up chemical reactions without being consumed in the process. They work by providing an alternative reaction pathway with a lower activation energy. Here’s how they affect equilibria and ΔH (enthalpy): ​ Catalysts do not change the position of equilibrium or the equilibrium constant (K). ​ Catalysts do not alter ΔH, the enthalpy change of the reaction. ​ They simply make the reaction reach equilibrium faster by lowering the activation energy. Summary of How to Maximize Product Yield Using Le Chatelier's Principle: Reaction For Endothermic Reactions For Exothermic Reactions Condition (ΔH > 0) (ΔH < 0) Concentration Increase reactant Increase reactant of Reactants concentration → shifts concentration → shifts equilibrium to products equilibrium to products Concentration Decrease product Decrease product of Products concentration → shifts concentration → shifts equilibrium to products equilibrium to products Temperature Increase temperature → Decrease temperature → shifts equilibrium to products shifts equilibrium to products (endothermic direction) (exothermic direction) Pressure (for Increase pressure → shifts Increase pressure → shifts gaseous equilibrium to side with equilibrium to side with reactions) fewer moles of gas fewer moles of gas Catalyst No effect on equilibrium No effect on equilibrium position but helps reach position but helps reach equilibrium faster equilibrium faster Collision Theory: Reactions occur when molecules collide with enough energy and in the correct orientation. Activation Energy: The minimum energy required for a collision to result in a reaction. Collision Geometry: Molecules must be properly oriented for the reaction to occur. Temperature: An increase in temperature speeds up the reaction by increasing the energy and frequency of collisions. Other Factors: Concentration, surface area, and catalysts also influence reaction rates. Unit 4: Acids and Bases Redox reaction: Occurs when there is a change in the oxidation numbers of the elements, where one is oxidized (loses electrons) and another is reduced (gains electrons). No redox reaction: If the oxidation numbers of all elements remain the same before and after the reaction, no redox has occurred.