Grade11 Chemistry Course Review

Unit1 - Matter and Chemical Bonding

Atomic(原子的) Structure; Isotopes(同位素) and Radioisotopes(放射性同位素)

Atomic Structure

Composition of an Atom:

• $ e=1.6×10^{-19} C $
• $ ^{A}_{Z}X $ Neutron Number ($ N $) Atomic Number ($ Z $)
• Mass Number ($ A $): $ Z + N $ (e.g., oxygen-16: $ 8p + 8n \to A=16 $)

Ground State(基态): The electrons(电子) in a atom occupies the lowest energy levels , making it stable and non-radiative.

Development of Atomic Structure: Plum Pudding Model(枣糕模型) → Nuclear Model(核式结构) → Bohr’s Atomic Orbitals(波尔原子轨道) → Modern Atomic Structure(现代原子结构)

Bohr’s Atomic Orbitals(Ground State(基态) Hydrogen Atom): Electrons move in quantized orbits with fixed energy levels; photon emission/absorption occurs during transitions.

Note: Nuclear changes are unrelated to chemical reactions; valence electrons(核外电子) participate in chemical reactions.

Isotopes and Radioisotopes

Nuclide(核素): An atomic nucleus(原子核) defined by a specific number of protons ($ Z $) and neutrons ($ N $), with a distinct mass number ($ A = Z + N $) and energy state.

Isotopes: Same Z, different N ()

Radioisotopes: Radioactive Isotopes Note:N-15 and O-18 are non-radioactive

Periodic Table Organization and Trends

• Atomic diameter(原子直径)
  • Across a period (left to right): Gradually decreases (increased nuclear charge pulls electrons closer, shrinking the atom).
  • Down a group (top to bottom): Gradually increases (additional electron shells expand the atomic radius).
  • Atomic Diameter (原子直径) → Bond Length (键长):Smaller atoms can get closer to each other, forming shorter bonds (e.g., C-C bond in diamond is shorter and stronger than Si-Si bond in silicon).
  • Bond Length → Bond Energy (键能):Shorter bonds = stronger attraction between nuclei and shared electrons → higher bond energy (harder to break).
• Electronegativity(电负性)
  • Across a period: Increases (smaller atomic radius and stronger nuclear attraction for electrons).
  • Down a group: Decreases (larger atomic radius weakens nuclear pull on valence electrons).
  • Exception: Noble gases (e.g., He, Ne) have negligible electronegativity (they rarely form bonds).
• First ionization energy(第一电离能)
  • Across a period: Generally increases (higher nuclear charge makes electrons harder to remove), but with irregularities (e.g., Group IIA > IIIA due to easier p-orbital electron loss).
  • Down a group: Decreases (outer electrons are farther from the nucleus and easier to remove).
  • Note:In main group elements, Group IIA and Group VA elements exhibit higher first ionization energies than their adjacent elements. This occurs because their fully filled s-orbitals or half-filled p-orbitals result in lower ground-state energy.
• Nonmetallic character(非金属性)
  • Across a period: Increases (elements gain electrons more easily, e.g., fluorine is the most nonmetallic).
  • Down a group: Decreases (e.g., in halogens, $F > Cl > Br > I$).
  • Boundary: The upper-right corner (F, O, Cl) has the strongest nonmetallic properties, while the lower-left (e.g., Cs, Fr) is the most metallic.
  • Note:The strength of nonmetallic character is positively correlated with the acidity of its highest oxide’s hydrates and the stability of its hydrides.

Ionic and Covalent Bonding

Forces(作用力)

• Chemical Bonds(化学键) Chemical Changes

  • Ionic Bond(离子键)

    • Presence of metal ions or ammonium ions(铵根); Electronegativity difference(电负性差值) typically greater than 1.7
    • $ {AlCl}_{3} $ predominantly forms Covalent Bonds rather than Ionic Bonds($ \Delta EN = 1.55 < 1.7 $)

  • Covalent Bond(共价键)

    • Bonding via Shared Electron Pairs(共用电子对); Electronegativity difference typically less than $ 1.7 $

  • Metallic Bond(金属键)

    • Generally Metallic Elements

• Intermolecular Forces(分子间作用力) Physical Changes

  • van der Waals Forces(范德华力)
    • Larger Relative Molecular Mass Leads to Stronger van der Waals Forces and Higher Melting/Boiling Points(Without Hydrogen Bonding Influence)
  • Hydrogen Bond(氢键): Highly Electronegative Elements($ N, O, F $) Bonded to Hydrogen
    • Intramolecular Hydrogen Bond(分子内氢键):H-bond formed within the same molecule between $ H $ and $ O/N/F $
    • Intermolecular Hydrogen Bond(分子间氢键):H-bond formed between different molecules Results in higher melting/boiling points of molecular crystals and greater water solubility (due to hydrogen bonding with water)

Polarity of bonds and molecules

• Polar covalent bond(极性共价键): Electron density shifts toward the more electronegative atom.
• Polar molecule: Asymmetric charge distribution in molecules. Note: $ O_{3} \; \& \; {NH}_{3} $ is Polar molecule

Nomenclature (naming and writing formulas for chemical compounds)

• Textbook

Unit 2 - Chemical Reactions

Law of Conservation of Mass; Balancing Chemical Equations

• Conservation of Mass:The total mass of a closed system remains constant during chemical reactions or physical changes
• Balancing Chemical Equations: Three Conservation Principles for Balancing Chemical Equations
  • Conservation of Elements(元素守恒):Types and quantities of elemental atoms are conserved. The total number of atoms for each element must be equal on both sides of the equation.
  • Conservation of Charge(电荷守恒):The total electric charge in an isolated system is constant; charge can only be transferred.
  • Conservation of Electrons(得失电子守恒): In redox reactions(氧化还原反应), the number of electrons lost by the reducing agent equals those gained by the oxidizing agent. In redox reactions, total electrons lost by reductants = total electrons gained by oxidants.
  • Note: Generally, we first assume the coefficient of the most complex reactant to be $ 1 $ for balancing calculations. Alternatively, first determine the ratio of the oxidizing agent to the reducing agent (balancing electron transfer).

Types of Chemical Reactions (including predicting products of reactions)

• Combination/Synthesis Reaction(化合反应): A chemical reaction where two or more substances combine to form a single new compound. Not Necessarily a Redox Reaction

• Decomposition Reaction(分解反应): A chemical reaction where a single compound breaks down into two or more simpler substances. Not Necessarily a Redox Reaction

• Single Displacement Reaction(置换反应): A chemical reaction where an element reacts with a compound, displacing another element from it to form a new compound. Must be a redox reaction

• Double Displacement Reaction(复分解反应): A chemical reaction where two compounds exchange components to form two new compounds. Definitely Not a Redox Reaction

Chemical Reactions in Industry (five Principles of Green Chemistry)

• Textbook

Unit 3 - Quantities in Chemical Reactions (Nothing particularly noteworthy, just refer to the textbook)

• Mole Calculations (mass ↔ mol ↔ particles)
• Law of Definite Proportions and Percent Composition
• Quantitative Analysis in everyday life
• Empirical and Molecular Formula (including Hydrates)
• Stoichiometry Calculations (mass-mass problems)
• Limiting and Excess Reactants
• Theoretical, Actual and Percentage Yield

Unit 4 - Solutions and Solubility

Types of Solutions and Dissolving Process (intermolecular forces of attraction)

• Solute molecule diameter:
  • Solution: $ <10 nm $;
  • Colloid: $ 10-100 nm $;
  • Suspension: $ >100 nm $.
• Ionic crystals(离子晶体): Dissolve by ionizing into freely moving ions
• Molecular crystals(分子晶体): Dissolution follows the “like dissolves like” principle(相似相容原理): Polar molecules are mutually soluble, while nonpolar molecules are not. Water is a polar molecule. The presence of intermolecular hydrogen bonds increases solubility. Water molecules form intermolecular hydrogen bonds.
• Note: In a solution, the greater the number of free ions per unit volume (ionic concentration), the higher the electrical conductivity. In contrast, molecular substances generally do not conduct electricity.
• Potassium(钾盐), sodium(钠盐), ammonium(铵盐), nitrate salts(硝酸盐), and Acetate(醋酸盐) are all soluble; for others, just remember common insoluble compounds and the slightly soluble $ {CaSO}_{4} $.

Factors Affecting the Rate of Dissolving and Solubility

Predicting Precipitate Formation using Solubility Guidelines

• ? Textbook

Writing Net Ionic Equations and identifying spectator ions

• Textbook

Concentration and Dilution; Preparing Solutions (technique and equipment)

• Textbook

Stoichiometry Calculations for Solutions

• Textbook

Water Quality, Pollutants and Water Treatment

• Textbook

Acids and Bases (including properties, strength, theories)

• Acid
  • Strong Acids: Sulfuric acid (H₂SO₄)(硫酸) Nitric acid (HNO₃)(硝酸) Hydrochloric acid (HCl)(盐酸)
  • Moderately Strong Acids: Phosphoric acid (H₃PO₄)(磷酸)
  • Weak Acids: Hypochlorous acid (HClO)(次氯酸) Sulfurous acid (H₂SO₃)(亚硫酸) Hydrofluoric acid (HF)(氢氟酸) Hydrosulfuric acid (H₂S)(硫化氢) Carbonic acid (H₂CO₃)(碳酸)
  • Note:The suffix “-ate” denotes the standard acid radical (e.g., sulfate(硫酸根)), while the suffix “-ite” denotes the “-ous acid” radical with lower oxygen content (e.g., sulfite(亚硫素根)). Typically, “-ite” acids are weaker acids.

pH Scale and Calculations for pH and [H3O+]

• Textbook

Neutralization reactions and titration procedure and calculations

• Neutralization reactions:H+ reacts with OH- Note:H+ is equivalent to H3O+
• titration procedure and calculations:
  • textbook(This might differ from what I learned)

Unit 5 - Gases and Atmospheric Chemistry

• Kinetic Molecular Theory: Characteristics of the Gas State
• Gas Laws (relationships between P, V and T; combined gas law)
• Dalton’s Law of partial pressures; (related to the atmosphere)
• Avogadro’s hypothesis and Molar Volume
• Ideal Gas Law Calculations $$ PV = nRT $$ (BTW., 你也可以当成牛头人(nTR)定理记, 即$ PV = nTR$)
• Density of gases at STP and otherwise
  • Note: Certain compounds (e.g., H₂O, Br₂) maintain liquid phase at STP (273.15 K(0°C), 101.325 kPa(1 atm)), making the ideal gas molar volume (22.4 L/mol) inapplicable due to their condensed state properties.
• Identifying Gases using MM and MF as an extension of the Ideal Gas Law
• Gas laws and Stoichiometry
• Atmospheric Pollutants and Air Quality Health Index

Note

• Drawing Orbital Diagrams(轨道表示式): Arrange orbitals in order of increasing energy: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, … The number indicates the principal energy level (1,2,3,4 where K,L,M,N correspond to the 1st,2nd,3rd,4th levels respectively). The letter denotes the shape of the electron cloud (s: spherical(球形), p: dumbbell-shaped(哑铃形)…). The superscript shows the number of electrons in that orbital. Then fill electrons according to:
  • s-orbitals: max 2 electrons
  • p-orbitals: max 6 electrons
  • d-orbitals: max 10 electrons… Continue until all electrons (equal to the atomic number) are placed. By analyzing the relationship between the number of valence electrons(最外层电子) and the octet rule(八电子稳定结构), we can predict an element’s possible oxidation states(化合价) (how many electrons an atom may lose or gain to achieve stability).
• Organic Chemistry(有机化学):
  • Isomerism (同分异构):
    • Structural isomers (结构异构): Same formula, different connectivity (e.g., C₄H₁₀: butane vs. isobutane).
    • Stereoisomers (立体异构): Same connectivity, different spatial arrangement (e.g., cis/trans alkenes). Note:A double bond(双键) must be present. cis-(顺式)cis-configuration(顺式构型): The two groups with higher relative molecular masses are on the same side of the double bond. trans-(反式)trans-configuration(反式构型):The two groups with higher relative molecular masses are on the different side of the double bond.
  • IUPAC Rules: 1.Identify longest carbon chain. 2.Number to give substituents lowest locants. 3.Prefix + parent + suffix (e.g., 2-methylpropan-1-ol).

Appendix

• S:soluble(可溶)
• SS:slightly soluble(微溶)
• I: insoluble(不溶)