SCH4U practice exam: Grade 12 Chemistry questions and exam rules

Each daily paper has 8 original questions worth 25 to 35 marks. The Grade 12 Chemistry (SCH4U) paper covers organic chemistry, rate equations, equilibrium, acids, bases and buffers, and electrode potentials; its NMR and transition metal questions go beyond SCH4U. The Grade 11 Chemistry paper adds enthalpy and Hess's law, molecular shapes, intermolecular forces and kinetics, which SCH4U also tests.

How the SCH4U exam counts in 2026-27

In Grade 12 science in Ontario, your final mark is now 65% classroom work, a 25% written exam, and 10% attendance and participation, with the exam written in your board's exam period. The prerequisite for SCH4U is Grade 11 university preparation chemistry (SCH3U). These figures come from the Ministry of Education's September 2026 update to Growing Success.

What's on the SCH4U exam: the strands

• Organic chemistry: naming, functional groups and reactions.
• Structure and properties of matter: atomic structure, bonding and molecular shape.
• Energy changes and rates of reaction: enthalpy, calorimetry and reaction rates.
• Chemical systems and equilibrium: equilibrium constants, solubility, and acids and bases.
• Electrochemistry: redox reactions and electrochemical cells.
• Scientific investigation skills and career exploration run through every unit.

SCH4U practice exam questions with answers

We wrote these for this page, one from each main strand.

1. Organic chemistry. Name CH₃CH₂CH₂OH and say what forms when it is gently oxidized. Answer: it is propan-1-ol (1-propanol), a primary alcohol. Gentle oxidation gives the aldehyde propanal, and further oxidation gives propanoic acid. A secondary alcohol would give a ketone instead.

2. Structure and properties. Predict the shape of H₂O and explain why it is polar. Answer: oxygen has two bonding pairs and two lone pairs, so the molecule is bent, at about 104.5°. The bonds between oxygen and hydrogen are polar and, because the shape is bent, their dipoles don't cancel, so the molecule is polar. Try a shape question from our Chemical Bonding course, then press Mark.

3. Calorimetry. A reaction of 0.0250 mol of reactant warms 50.0 g of water by 6.0 °C. Find ΔH in kJ/mol. Use c = 4.18 J/(g °C). Answer: q = mcΔT = 50.0 × 4.18 × 6.0 = 1,254 J = 1.254 kJ. The water gained heat, so the reaction released it: ΔH = −1.254 ÷ 0.0250 = −50.2 kJ/mol. The Enthalpy Calculator checks these.

4. Solubility equilibrium. K_sp for silver chloride is 1.8 × 10⁻¹⁰. Find its molar solubility. Answer: AgCl ⇌ Ag⁺ + Cl⁻, so K_sp = s × s = s² and s = √(1.8 × 10⁻¹⁰) = 1.3 × 10⁻⁵ mol/L. A small K_sp means a sparingly soluble salt.

5. Electrochemistry. A cell is built from zinc (E° = −0.76 V) and copper (E° = +0.34 V) half-cells. Find E°cell and name the anode. Answer: E°cell = E°cathode − E°anode = 0.34 − (−0.76) = +1.10 V. Zinc has the lower reduction potential, so it is oxidized and is the anode. A positive cell potential means the reaction is spontaneous.

Use the daily papers as practice exams

1. Alternate the SCH4U and SCH3U papers, and work to the suggested time, 35 to 45 minutes.
2. Skip the NMR and transition metal questions.
3. Show units and the sign of every energy change.
4. Mark each paper and note which strand each lost mark belongs to.

Common SCH4U mistakes

• Getting the sign of ΔH backward: if the water warms, the reaction is exothermic and ΔH is negative.
• Ignoring lone pairs when predicting shape.
• Including solids in an equilibrium expression.
• Mixing up the anode and cathode: oxidation at the anode, reduction at the cathode.
• Numbering the carbon chain from the wrong end when naming organic compounds.

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