SCH4U Chemistry: the course map (24 ideas across organic, structure, energy and rates, equilibrium and electrochemistry), the calculator chapters as procedures, the naming chapters as vocabulary, and what an exam actually asks

SCH4U is Ontario's Grade 12 university chemistry: organic chemistry, atomic structure and bonding, energy changes and rates, chemical equilibrium (including acids and bases) and electrochemistry. Our map has 24 ideas in teaching order. About half are procedures you learn by redoing worked problems, such as pH, buffers, enthalpy, equilibrium constants and cell potentials, and half are vocabulary and models you learn by recall. Here is the map, and the method for each half.

What SCH4U is, and what it assumes

SCH4U is the Ontario course code for Chemistry, Grade 12, University Preparation. Its prerequisite is SCH3U, the Grade 11 university chemistry course, and it assumes that course's foundations are still in working order: moles, stoichiometry, the gas laws, balancing equations and the periodic table. Many classes spend the first week on exactly that review, which is why our map carries a 24th idea for it.

The mathematics is modest but specific. Logarithms, from MHF4U or the Grade 11 functions course, run the acids and bases unit, because pH is a logarithm and nothing else. Algebra runs equilibrium, where you solve for an unknown concentration from an expression. Scientific notation and significant figures run everything. There is no calculus in SCH4U.

What it leads to is first-year general chemistry, which most science, health-science and engineering programs require, and whose core is the equilibrium and acid–base chemistry of this course. The Grade 12 course also overlaps heavily with AP Chemistry; the AP Chemistry study guide has that exam's shape, and the FAQ below has the overlap in a paragraph.

As with every Ontario science course, strand A covers the skills of inquiry and runs through all the units rather than standing alone, so our map starts at strand B. The Ministry's course description is the source for the code, title and prerequisite; the descriptions below are our own.

The course map: 24 ideas in the order they are taught

Our SCH4U map, in the order most classes meet the ideas, grouped by strand. Chapter 3 of the free playbook turns a list like this into a one-page map with a mark beside each idea; this is the list to write on it.

Organic chemistry (strand B)

1. Organic functional groups and IUPAC nomenclature
2. Hydrocarbons: alkanes, alkenes, alkynes and their reactions
3. Structural and stereoisomers
4. Organic reaction types: addition, elimination, substitution, esterification
5. Polymers: addition and condensation polymerisation

Structure and properties of matter (strand C)

6. Quantum mechanical model of the atom; quantum numbers
7. Electron configurations and periodic trends
8. Ionic and covalent bonding; Lewis structures; electronegativity
9. Molecular shape (VSEPR) and polarity
10. Intermolecular forces and physical properties

Energy changes and rates of reaction (strand D)

11. Enthalpy changes and calorimetry
12. Hess's law and enthalpies of formation
13. Reaction rates and factors affecting them
14. Rate laws and reaction order
15. Activation energy, catalysts and reaction mechanisms

Chemical systems and equilibrium (strand E)

16. Dynamic equilibrium and the equilibrium constant
17. Le Chatelier's principle
18. Solubility equilibria and Ksp
19. Acid–base theories, pH and strong/weak acids
20. Buffers and acid–base titration

Electrochemistry (strand F)

21. Oxidation numbers and balancing redox reactions
22. Galvanic cells and standard reduction potentials
23. Electrolytic cells and Faraday's laws

Prerequisite review

24. Gas laws and stoichiometry

Read down the list once and you can see the two kinds of idea. Some rows are things you calculate; some rows are things you name, draw or explain. The next section sorts the same 24 the other way, and that sort is the whole method.

Procedures or vocabulary? The map sorted the other way

A procedure is an idea whose questions have a set-up, a substitution and a numerical answer. You learn one by the worked-example cycle: read a solved problem slowly, redo it cold, do a sibling with new numbers, log every wrong line. Sweller and Cooper (1985) found that students who studied worked examples learned algebra procedures faster, and with fewer errors afterwards, than students who only solved problems from the start. The cycle, with its marking rules, is in how to study math.

A vocabulary idea is one whose questions ask you to name, draw, classify or explain. You learn one by recall: close the notes, produce the name or the structure, check, and come back to the misses on a later day. Roediger and Karpicke (2006) showed that a group that recalled a passage remembered more of it a week later than a group that reread it, even though the rereaders felt more confident at the time.

Here are the 24 ideas sorted into the two columns. Several ideas sit in both, and the table says which half of them is which.

Procedures: worked example, redo cold, sibling, error log	Vocabulary and models: recall cards, redrawn structures, self-explanation
Calorimetry: q = mcΔT and the enthalpy of a reaction from it (11)	Functional groups and IUPAC naming (1)
Hess's law and enthalpies of formation (12)	The hydrocarbon families and their reactions (2)
Rate laws and reaction order from data (14)	Structural and stereoisomers (3)
The equilibrium constant and ICE tables (16)	The four organic reaction types (4)
Ksp and molar solubility (18)	Addition and condensation polymers (5)
pH, pOH, Ka and Kb (19)	Quantum numbers and orbital shapes (6)
Buffers and the Henderson–Hasselbalch equation (20)	Electron configurations and periodic trends (7)
Titration curves and the equivalence point (20)	Lewis structures and electronegativity (8)
Cell potentials from standard reduction potentials (22)	VSEPR shapes and polarity (9)
Faraday's laws: moles from charge and time (23)	Intermolecular forces and the properties they predict (10)
Stoichiometry and the gas laws (24)	Factors affecting rate; activation energy and mechanisms (13, 15)
Balancing redox equations (21): a procedure run on a vocabulary of rules	Le Chatelier's directions (17); oxidation-number rules (21)

Idea 9, the shapes, has its own page: molecular geometry and bond angles, every shape, with the table and the lone-pair rule. It is the clearest case of a vocabulary idea that is learned best by deriving the table from five parent shapes rather than memorizing thirteen rows.

Worked examples: one procedure, one vocabulary

pH of a strong acid, then a buffer (ideas 19 and 20)

The procedure half, through the cycle.

The worked example: what is the pH of 0.025 mol/L hydrochloric acid? HCl is a strong acid, so it dissociates completely and [H⁺] = 0.025 mol/L. pH = −log(0.025) = 1.60. Two significant figures in the concentration give two decimal places in the pH.

Now redo it cold on a blank page, then do the sibling: a buffer that is 0.10 mol/L in acetic acid and 0.10 mol/L in sodium acetate, with Ka = 1.8 × 10⁻⁵ for acetic acid. First pKa = −log(1.8 × 10⁻⁵) = 4.74. Then the buffer equation: pH = pKa + log([A⁻]/[HA]) = 4.74 + log(0.10/0.10) = 4.74 + log(1) = 4.74 + 0 = 4.74. A buffer with equal amounts of acid and conjugate base sits at its pKa.

The wrong lines a marker sees, for the error log: treating the buffer as the weak acid alone and setting up an ICE table (the acetate changes everything; the buffer equation is the short route); and writing [HA]/[A⁻] in the log, which flips the sign of the correction whenever the two concentrations differ. The check: more base than acid means a pH above the pKa.

Naming and shape (ideas 1 and 9)

The vocabulary half, by recall cards, not worked problems.

Card one, front: "Name CH₃CH₂CH₂OH." Back: propan-1-ol. Three carbons give the stem "propan-", the OH group gives the suffix "-ol", and the locant 1 says the OH is on an end carbon. The sibling card asks for propan-2-ol, with the OH on the middle carbon, so that the locant is tested and not just the suffix.

Card two, front: "The shape of NH₃, and its approximate bond angle." Back: nitrogen has three bonds and one lone pair, four electron domains, so the electron geometry is tetrahedral; remove the lone pair and the molecular shape is trigonal pyramidal, with a bond angle of about 107°, a little under the tetrahedral 109.5° because the lone pair pushes the bonds together. The sibling card is water.

Neither card has a calculation in it, and neither is learned by reading the chapter again. They are learned by being asked on three separate days.

What an exam actually asks

Across all five strands, almost every SCH4U exam question is one of three shapes. Knowing the shape before you read the question is half the mark.

1. A calculation with a set-up. Write the equation in symbols, substitute with units, state the answer with the right number of significant figures. The marks are usually split across those three lines, so a right answer with no set-up loses most of them, and a right set-up with a slip at the end keeps most of them. Practise by writing the symbol line first on every problem.
2. An explain-why. Two sentences that name the model and apply it. Why does water boil at a higher temperature than hydrogen chloride? Because water molecules hydrogen-bond and HCl molecules only have dipole–dipole forces, and stronger intermolecular forces need more energy to separate. The first sentence names the force; the second connects it to the property. Practise by saying the answer aloud, in two sentences, before checking.
3. A predict-the-direction. Which way does an equilibrium shift when the pressure rises, which electrode is the anode, which of two acids is stronger. These are rule-based and quick, and they are the ones students lose by hesitating. Practise them as cards: situation on the front, direction and reason on the back.

"I understand it" is not the same as "I can set it up in four minutes with the clock running." The difference is practice under the exam's conditions. Two weeks before the exam, do a set that mixes all three shapes across all five strands, as the guide to mixed practice describes, because a set that stays inside one chapter tells you the chapter.

How to study SCH4U: chemistry help that teaches

The method follows from the two halves and the three shapes.

• Procedures by the cycle, with an error log. In our experience of marking, most lost marks in chemistry are a set-up or a unit, not arithmetic: a missing conversion from grams to moles, a Kelvin forgotten, a log taken of the wrong thing. Every such line goes in the log with the right line beside it, and the problem is redone cold the next day. The procedures column of the table is the list of ideas this applies to.
• Vocabulary by spaced recall cards. Make the cards from the chapter's bold terms and its structures, one fact per card, the answer never on the front. Then put them on a calendar: tonight, in two or three days, in a week. How spaced repetition schedules work has the dates.
• Structures redrawn from memory. Lewis structures, the VSEPR shapes, a titration curve with its equivalence point labelled, a galvanic cell with the anode, cathode and salt bridge. Blank page, draw, compare, circle what is missing.
• Reading the chapter so it sticks. A chemistry chapter is dense, and reading it once at speed leaves almost nothing. Survey it, turn the headings into questions, read to answer them, recite and review: SQ3R on a chemistry chapter is that routine, written for exactly this kind of text. The science study guide how to study for science has the rest of the method.
• A plan grid. The week-by-week table below is the semester; a weekly grid that fits homework around it is the study-plan guide in the how-to-study section.

On chemistry help: a worked example read after your own attempt is help, and it is how the procedures column is learned. An answer read before an attempt is not help; it is a line you will recognise on the exam and be unable to produce. A solver app against learning the solution has the longer argument.

A week-by-week plan for a semester: the SCH4U exam review that starts in week 1

An 18-week semester, the strands in the usual order. Each row names the recall set to run, the worked-example cycle to do, and the mixed set once there is enough to mix.

Weeks	Strand and ideas	Recall set	Worked-example cycle	Mixed set
1	Prerequisite review (24)	Mole and unit definitions	Stoichiometry and gas-law problems redone cold	None yet
2–4	Organic (1–5)	Functional groups, naming, isomers, reaction types, polymers; new cards every class	None: this strand is almost all vocabulary	Naming cards across all five ideas by week 4
5–8	Structure and properties (6–10)	Quantum numbers, configurations, trends, Lewis structures, shapes, forces	None	Cards mixed across strands B and C
9–11	Energy and rates (11–15)	Rate factors, activation energy, mechanisms	Calorimetry, Hess's law, rate laws: one example a night, redone cold the next	From week 10, a set of eight problems and twelve cards mixed across B to D, every week
12–15	Equilibrium and acids and bases (16–20)	Le Chatelier's directions, acid–base theories	ICE tables, Ksp, pH, buffers, titration: the longest cycle of the course	The weekly mixed set, now B to E
16	Electrochemistry (21–23)	Oxidation-number rules, anode and cathode	Cell potentials and Faraday's laws	B to F
17	Mixed review across all strands	Every card whose last mark was Shaky or Cannot	Every procedure in the table, from a blank page	A full timed set, all three question shapes, marked and logged
18	Exam week	The error log, once	None new	The light review the night before, and sleep

Week 18 is the one-week plan in the how-to-study section: a diagnostic on day 7, spaced sessions, a timed run two days out, a light review.

What carries into first year

The equilibrium strand and the acids and bases unit are the core of first-year general chemistry, which runs them again with more algebra and more rigour, so ideas 16 to 20 are worth owning rather than passing. Organic chemistry returns as a course of its own, usually in second year, where the naming and the reaction types from strand B are assumed. The quantum strand returns with mathematics attached: the orbitals you drew become solutions of an equation. Thermochemistry and electrochemistry return inside first-year thermodynamics. Almost nothing in SCH4U is left behind.

SCH4U on one screen

• Five strands, 24 ideas: organic (5), structure and properties (5), energy and rates (5), equilibrium (5), electrochemistry (3), and the prerequisite review (1).
• Two kinds of idea: procedures, learned by worked example, redo cold, sibling and error log; vocabulary and models, learned by recall cards, redrawn structures and self-explanation on a spaced calendar.
• Three question shapes: a calculation with a set-up, an explain-why in two sentences, a predict-the-direction.
• The math: logarithms for pH, algebra for equilibrium, significant figures throughout.
• Mixed sets from week 10; a full timed set in week 17; the error log once in week 18.