Grade 12 · Science

Grade 12 science

Grade 12 science is university preparation: biochemistry and genetics, equilibrium and electrochemistry, fields and the nature of light. Here is what the year covers, where students usually get stuck, and one way to help.

What your teen learns this year

Grade 12 science is usually taken as separate courses:

  • Biology. Biochemistry, metabolism, molecular genetics, homeostasis and population dynamics.
  • Chemistry. Organic chemistry, structure and bonding, energy and reaction rates, equilibrium, and electrochemistry.
  • Physics. Dynamics, energy and momentum, gravitational, electric and magnetic fields, and the wave nature of light.
  • Earth and space science, in some provinces, as a course of its own.

Ontario's courses are SBI4U, SCH4U and SPH4U (with college-level versions). Other provinces name them differently, such as Biology 30 in Alberta and Saskatchewan and Chemistry 40S in Manitoba.

Where kids usually get stuck

  1. 1Shifting toward the substance that was added. An equilibrium shifts to use up what was added, so adding a reactant pushes it toward the products.
  2. 2Thinking a catalyst shifts an equilibrium. A catalyst speeds up both directions equally. The equilibrium is reached faster but doesn't move.
  3. 3Treating “centripetal force” as an extra force. It is a job some real force is doing, like gravity, tension or friction, pulling toward the centre of the circle.

One of Pip's tricks

Shift to undo the change

Use it when a system at equilibrium is disturbed and you must predict which way it shifts (Le Chatelier's principle).

  1. Name the change, then shift in the direction that partly undoes it: add a substance and the system uses it up; remove one and the system makes more.
  2. Temperature: treat heat as a reactant (endothermic) or a product (exothermic), then apply the same rule.
  3. Pressure raised by shrinking the volume: shift toward the side with fewer moles of gas.
  4. A catalyst shifts nothing, and a shift only reduces a change; it never cancels it completely.

Watch it work. N₂ + 3 H₂ ⇌ 2 NH₃ + heat. More H₂ is added. To undo that, the system uses up H₂, so it shifts right, toward NH₃, and the amount of NH₃ goes up.

Why it works: at equilibrium the forward and reverse reactions run at the same rate. Adding a reactant speeds up the forward one until the rates match again, so the system moves part of the way back.

Try three

Tap a choice to see if it is right, with the reason.

  1. 1.N₂ + 3 H₂ ⇌ 2 NH₃ + heat. NH₃ is removed. The equilibrium shifts…

  2. 2.N₂ + 3 H₂ ⇌ 2 NH₃ + heat. The mixture is heated. The equilibrium shifts…

  3. 3.N₂ + 3 H₂ ⇌ 2 NH₃. The pressure is raised by shrinking the container. The equilibrium shifts…

How Sparkpip fits in

Pip, Sparkpip's tutor, works through questions like these with your teen one small step at a time, using methods like the one above.

Start freeSee how it works

Your curriculum

Sparkpip is built on the grade 12 science curriculum for your province or state. The official pages:

Also: Grade 11 science · Grade 12 math · Grade 12 English