In this course the investigation comes first. You go to the bench before anybody explains what you are about to see, because a question you have felt is worth ten questions you have been handed. The concept page arrives afterwards, and its only job is to account for what your class actually measured.
| Investigation | The question it opens |
|---|---|
| Sorting the Elements | Left alone with the data, would you have built the same table Mendeleev did? |
| Testing for Bond Type | Can you tell what holds a substance together without ever seeing inside it? |
| Sorting Five Reactions | Do reactions fall into families you could sort before anyone names them? |
| Building the Activity Series | Which metal wins when two of them want the same partner? |
| Oxides and Neutralisation | Why does one oxide make water acidic and another make it basic? |
| Finding an Empirical Formula | Can a balance alone tell you a formula you were never given? |
| Percentage Yield of a Precipitate | Where does the missing product go — and what if there is too much of it? |
| Preparing a Standard Solution | What does it take to make a solution whose concentration you can actually defend? |
| Titrating an Acid | How strong is the vinegar in the cupboard, to three figures? |
| Measuring a Gas Law | Squeeze a gas, heat a gas, weigh a gas — what stays fixed? |
Every page has the same seven parts: what you are trying to find out, what you have to work with, safety, the prediction you write down first, what to collect, what to bring to the consolidation discussion, and what you should not claim from your data. Read the whole page before the class it belongs to — especially the safety section, which is not optional reading and is not the same list twice.
What is different from Grade 10
You have done investigations before. Four things change this year, and they are the whole reason the course is worth taking.
- The answer is a number. Not “the mass went down” but “the mass fell by 0.34 g, which is thirty-four times the balance’s resolution”. Every measured quantity carries a unit and a defensible number of significant figures, from the first reading to the last line of the calculation.
- Uncertainty is handled numerically. “About the same” is retired. It is replaced by “unchanged to within the balance’s resolution”, or “the three titres agree within 0.10 mL”, which are statements that can be checked and can fail.
- You design. Most pages hand you a question and a bench of equipment rather than numbered steps. What to change, what to measure, what to hold still, and how many trials are yours to decide and yours to justify in writing before you run anything.
- You name the direction of an error, not just its existence. Saying “some product was lost” is Grade 10. Saying “product left on the filter paper pushes the recovered mass down, so our yield is an underestimate” is this course. Every page ends by asking for that.
A percentage yield over 100% is not a mistake to be quietly rounded away. It is information about your procedure, and the page will ask you what it tells you.
Standing rules — every lab day, no exceptions
These are not repeated on every page. They are assumed on every page.
- Eye protection on from the first move to the last of the cleanup, including while somebody else is still working. Long hair tied back, loose sleeves secured, closed-toe shoes.
- Know where the eyewash, the safety shower, the fire extinguisher, the fire blanket, and the spill kit are before you start. Not roughly. Point at each one.
- Add acid to water, never water to acid. Dilution releases heat. With the water already there, the heat spreads through a large volume; the other way round, it concentrates in a few drops that can boil and spit acid back out at you.
- Hot glassware and hot ceramic look exactly like cold glassware and cold ceramic. There is no visual difference. Assume anything near a heat source is hot until you have watched it cool.
- Never pipette by mouth. Use a bulb or a pipette pump, every time, for every liquid, including water.
- Waft, do not sniff. Cup a hand and draw the air toward you. Never put your face over a container and inhale.
- Never return unused chemical to the stock bottle. Take what you need. What is left over goes to the labelled waste container, not back into stock and not down the sink unless the page says so.
- Nothing is tasted. Nothing is food. Including substances that were food this morning.
- School reagents only, at the concentrations supplied, and combine only what your approved procedure lists. Substances that are harmless apart can make a toxic gas together and there is no way to tell by looking, which is why this rule is absolute rather than a matter of judgement.
- Nothing that makes a gas is ever sealed in a rigid container, and nothing sealed is ever heated.
- Report every incident the moment it happens, however small. A splash you rinsed off yourself is still something I need to know.
Any procedure you designed is checked by me before you run it, including what could go wrong and what you would do about it. Missing eye protection or an unchecked procedure means the written alternative instead, for everyone’s sake.
The full agreement, the hazard symbols, and the disposal routes: Safety in the Lab and Lab Safety and WHMIS.
Write-up format: Writing a Lab Report. Units, resolution, and how many figures you are entitled to: Significant Figures and Units and Measuring Well. Stuck at the bench with ten minutes gone? Getting Unstuck, then find me.