Chemistry

Almost everything around you that is alive, or was once alive, is built from carbon compounds, and so are fuels, plastics, medicines, flavours and fabrics. In this unit you will learn the language and logic of organic chemistry. You will draw molecules in structural, condensed and skeletal formulas and give them IUPAC names: first the hydrocarbons (alkanes, cycloalkanes, alkenes, alkynes and aromatic compounds), then every main functional group: alcohols, organic halides, ethers, aldehydes, ketones, carboxylic acids, esters, amines and amides. You will explain their physical properties (boiling point, solubility, odour) using intermolecular forces, and find structural, geometric (cis-trans) and optical isomers. You will predict the products of combustion, addition, substitution, elimination, oxidation, esterification, hydrolysis and condensation reactions, plan multi-step pathways, and see how addition and condensation polymerization make plastics, nylon, proteins and starch. Finally, you will weigh the benefits and risks of organic compounds in Canadian society, from microplastics and pesticides to industrial pollution in Sarnia, meet Canadian chemists and organic-chemistry careers, and write your own action plan.

Remember from Grade 11 (SCH3U): in Matter, Chemical Trends, and Chemical Bonding you drew Lewis structures, used electronegativity to predict polar bonds, and weighed the risks and benefits of common chemicals; in Chemical Reactions you balanced combustion equations for hydrocarbons; in Gases and Atmospheric Chemistry and Solutions and Solubility you used London forces, dipole-dipole forces and hydrogen bonds to explain boiling points and "like dissolves like". This unit uses all of these constantly.

The other units of this course build on what you learn here: Structure and Properties of Matter explains the orbitals, bonding and molecular shapes behind organic molecules; Energy Changes and Rates of Reaction measures the energy released when fuels burn; Chemical Equilibrium studies reversible reactions, like the esterification you meet here; Acid-Base and Solubility Equilibria treats carboxylic acids and amines as weak acids and bases; and Electrochemistry describes oxidation and reduction in terms of electrons.

Every lesson has worked examples, diagrams, a hands-on activity that is safe to do at home with a grown-up (hazardous reagents are only described, never used at home), lots of practice and a short quiz. A molecular model kit, or toothpicks with gumdrops or modelling clay, is very helpful.

Curriculum: The Ontario Curriculum, Grades 11 and 12: Science (2008), Chemistry, Grade 12, University Preparation (SCH4U), Strand B: Organic Chemistry, with Strand A (Scientific Investigation Skills and Career Exploration) woven through the lessons.

Why does neon glow red, water boil at 100 °C and diamond cut glass, while graphite slides off onto paper? In this unit of Grade 12 Chemistry you will answer questions like these by going deep inside the atom and then building back up to the properties of real materials.

You will start with the evidence behind atomic models: Thomson's electron, Rutherford's nucleus and Bohr's energy levels, which explain the line spectra of the elements. Then you will meet the quantum mechanical model: matter waves, the uncertainty principle, orbitals and the four quantum numbers. You will write electron configurations with the aufbau principle, the Pauli exclusion principle and Hund's rule, and use them to explain the s, p, d and f blocks of the periodic table and the exceptions in its trends.

Next comes the shape of molecules. You will predict three-dimensional shapes with VSEPR theory (developed by Canadian chemist Ronald Gillespie and Ronald Nyholm), including molecules with expanded octets, describe bonding with hybrid orbitals and sigma and pi bonds, and decide whether molecules are polar. You will use intermolecular forces to explain boiling points, viscosity, surface tension, capillary action and vapour pressure, and compare ionic, molecular, covalent network and metallic solids, including a full investigation to classify unknown solids.

Finally, you will assess technologies that come from this science (spectroscopy, MRI, X-ray crystallography, lasers) and specialized materials (Kevlar, composites, superconductors, nanomaterials), weighing their benefits against their environmental impact, and meet Canadian scientists who shaped the field.

Remember from Grade 11: in SCH3U (Matter, Chemical Trends, and Chemical Bonding) you used atomic structure, effective nuclear charge, periodic trends, Lewis structures, electronegativity and the properties of ionic and molecular compounds, and in Gases and Atmospheric Chemistry you met the three intermolecular forces. This unit explains why those patterns exist. The other units of this course are Organic Chemistry, Energy Changes and Rates of Reaction, Chemical Equilibrium, Acid-Base and Solubility Equilibria and Electrochemistry.

Scientific investigation skills (strand A) are woven through the lessons. Every lesson has worked examples, a hands-on activity that is safe at home (with a grown-up where noted), plenty of practice and a short quiz. Laboratory work with flames and chemicals is described for the school lab only.

Curriculum: The Ontario Curriculum, Grades 11 and 12: Science (2008), Chemistry, Grade 12, University Preparation (SCH4U), strand C. Structure and Properties of Matter: C1.1 and overall expectation C1 (assessing the benefits and environmental impact of products and technologies), overall expectation C2 (including its terminology) with C2.2 to C2.6 (investigating molecular shapes and physical properties) and C3.1 to C3.5 (atomic structure and bonding), with strand A expectations integrated.

This unit answers two questions about every chemical reaction: how much energy does it release or absorb, and how fast does it happen? In the first half (thermochemistry) you will compare the energy changes in physical, chemical and nuclear processes, write thermochemical equations, measure enthalpy changes with coffee-cup and simple combustion calorimeters using Q = mcΔT, and calculate enthalpy changes with Hess's law, standard enthalpies of formation and bond energies, including an inquiry that tests Hess's law with magnesium. You will use these ideas to evaluate energy technologies in Ontario and beyond. In the second half (kinetics) you will measure reaction rates, explain them with collision theory and potential energy diagrams, see how catalysts and enzymes lower activation energy, plan and carry out your own rate inquiry, and study reaction mechanisms, rate-determining steps and rate laws. The unit ends by applying both halves to make common reactions more efficient and sustainable.

Remember from Grade 11: in SCH3U you balanced equations, classified reactions (including combustion and neutralization), worked with moles, molar mass and solution concentration, and met catalysts; in SPH3U you used Q = mcΔT (with mass in kilograms), basic calorimetry, and the energy of fission and fusion. This unit builds on all of these. The sibling units of SCH4U are Organic Chemistry, Structure and Properties of Matter, Chemical Equilibrium, Acid-Base and Solubility Equilibria, and Electrochemistry; Chemical Equilibrium builds most directly on this unit.

Curriculum: Ontario Science, Grades 11 and 12 (2008), Chemistry SCH4U, strand D (Energy Changes and Rates of Reaction), expectations D1.1 to D3.7, with the Scientific Investigation Skills and Career Exploration expectations (strand A) woven into the lessons.

Many reactions do not go to completion. In a closed system they settle into dynamic equilibrium, where the forward and reverse reactions run at the same rate and the concentrations stop changing. In this unit you will learn to describe that state with the equilibrium law and the equilibrium constant K (and Kp for gases), to combine K values, and to use ICE tables to calculate K from experimental data and to predict equilibrium concentrations, using square roots, the quadratic formula and the small-K approximation with the 5 % rule. You will use the reaction quotient Q to predict which way a mixture will shift, and Le Châtelier's principle to predict the effects of changing concentration, pressure, volume and temperature, and of adding an inert gas or a catalyst. Two investigation lessons show how chemists test Le Châtelier's predictions (the cobalt(II) chloride equilibrium) and measure K with a colorimeter (the iron(III) thiocyanate equilibrium). An extension lesson explains why equilibria lie where they do, using entropy and Gibbs free energy (ΔG° = −RT ln K). The last two lessons apply everything to the Haber process and the contact process for sulfuric acid, and to equilibria in living things, the oceans and everyday technology: hemoglobin, carbon monoxide, CO₂ in blood and seawater, tooth enamel and kidney stones.

Remember from Grade 11: in Chemistry (SCH3U) you used the mole and mole ratios (Quantities in Chemical Reactions), molar concentration and dilution (Solutions and Solubility), and the ideal gas law and Dalton's law of partial pressures (Gases and Atmospheric Chemistry). All of these return here. Enthalpy, activation energy and catalysts are developed in this course's unit Energy Changes and Rates of Reaction.

Coming next: Acid-Base and Solubility Equilibria uses the same tools for Ka, Kb, Kw, Ksp, pH, buffers and titrations. You need a scientific calculator. Laboratory investigations that use hazardous chemicals are described for study only; every home activity uses safe kitchen materials.

Curriculum: The Ontario Curriculum, Grades 11 and 12: Science (2008, revised), Chemistry, Grade 12, University Preparation (SCH4U), strand E. Chemical Systems and Equilibrium: specific expectations E1.1, E1.2, E2.1 to E2.4 and E3.1 to E3.4 (E2.5 and E3.5 to E3.8, and the acid-base and solubility parts of E1.2, E2.1 and E3.4, are taught in Acid-Base and Solubility Equilibria). Scientific investigation skills and career exploration (strand A) are woven through the lessons, especially the two investigations and the industrial lesson. The entropy and free energy lesson is an extension that goes slightly beyond the listed expectations.

In this unit you will apply the equilibrium ideas from Chemical Equilibrium (equilibrium constants, ICE tables, the reaction quotient Q and Le Châtelier's principle) to two of the most important families of reactions in chemistry: proton transfers and dissolving and precipitating.

You will start with the Brønsted-Lowry theory, which defines acids as proton donors and bases as proton acceptors, and use it to identify conjugate acid-base pairs and predict which way a proton transfer goes. You will use the ion product of water, Kw, to move between [H₃O⁺], [OH⁻], pH and pOH, and the constants Ka and Kb to compare strong and weak acids and bases using dynamic equilibrium. You will calculate the pH and percentage ionization of weak acids, weak bases and salt solutions, and discover why Ka × Kb = Kw. Then you will explain how buffers resist pH change, calculate and interpret titration curves for strong and weak acids and bases, choose indicators, and solve titration problems from real data.

The second part of the unit turns to solubility equilibria: the solubility product, Ksp, molar solubility, predicting precipitation by comparing Q with Ksp, the common ion effect, and selective precipitation. The last lesson brings everything together to assess how these equilibria affect living things, the environment and technology: the blood buffer, hemoglobin, tooth enamel, kidney stones, acid lakes on the Canadian Shield, ocean acidification and the treatment of mine water.

Remember from Grade 11: in Solutions and Solubility (SCH3U) you learned the Arrhenius theory and hydronium, calculated pH from [H₃O⁺], compared strong and weak acids, titrated vinegar, and used a solubility table and net ionic equations to predict precipitates. Everything here builds on those skills. You will need a scientific calculator (with log, 10ˣ and root keys). Every lesson has worked examples, at least two diagrams, a hands-on activity using safe kitchen materials (with notes for a grown-up), plenty of practice with full answers, and a short quiz.

Coming next: in Electrochemistry you will study a different transfer, of electrons rather than protons, in batteries, corrosion and electrolysis.

Curriculum: The Ontario Curriculum, Grades 11 and 12: Science (2008, revised), Chemistry, Grade 12, University Preparation (SCH4U), strand E. Chemical Systems and Equilibrium: specific expectations E1.2, E2.1, E2.5 and E3.4 to E3.8, plus the acid-base and solubility parts of E2.2 and E2.4. Expectations E1.1, E2.2, E2.3, E2.4 and E3.1 to E3.3 are taught mainly in Chemical Equilibrium. Scientific investigation skills and career exploration (strand A) are woven into the lessons and tagged where a lesson clearly teaches them.

Every battery, every rusting nail and every aluminium can depends on one idea: electrons moving from one substance to another. In this unit you will identify oxidation and reduction using oxidation numbers, and balance redox equations by the half-reaction method in acidic and basic solution. You will predict which redox reactions happen on their own, build galvanic cells, and use the standard hydrogen electrode and a table of standard reduction potentials to calculate E°cell and predict spontaneity. Then you will run reactions backwards with electrolysis, use Faraday's law to calculate how much metal or gas a current produces, and see electrochemistry at work in refining, electroplating, aluminium and chlorine production, and in corrosion and its prevention. The unit ends with batteries, fuel cells and electric vehicles, where you will weigh their benefits against their environmental and social costs, including battery manufacturing, recycling and critical-mineral mining in Ontario. Labs include predicting redox reactions and building and measuring galvanic cells, with careful attention to safe handling of chemicals and electricity. The unit builds on Chemical Equilibrium and Energy Changes and Rates of Reaction, and draws on the electron structure and bonding from Structure and Properties of Matter.