IB Chemistry HLInquiry 1 — Exploring and DesigningPaper 3 & IACore skill~11 min read
Exploring
Long before you touch any glassware there is a stage that quietly decides how good your whole investigation will be. Exploring is where a vague interest becomes one sharp question you can actually answer — and where a guess becomes a prediction with real chemistry behind it.
📘 What you need to know
Exploring is the thinking stage: your curiosity plus some reading turns into a focused research question and a testable hypothesis.
A good research question names one thing you change, one thing you measure, the actual chemicals, and the range you will use.
Background reading gives you three things: the theory, a published value to compare with, and a method that is known to work.
A hypothesis is not a guess. Use If… then… because…, and put the chemistry in the “because”.
Comparing two similar systems usually shows more insight than measuring one thing on its own.
Check feasibility early: do you have the equipment, the chemicals, the time and a safe method?
Changing your question after you have read around it is a good sign, not a failure.
What exploring actually means
Most students start in the same place: “I want to do something with rates” or “something about acids”. That is a topic, not a question. You cannot design a method for a topic, because there is nothing in it to change and nothing to measure.
Exploring is the work of shrinking that topic down until only one relationship is left. It has three parts, and they happen in this order: have an idea, read around it, write the question. Skipping the middle step is why so many first attempts end up unanswerable.
Every stage removes options. By the end you should be able to picture the exact bench, the exact bottles, and the exact number you will write in your table.
What makes a research question good
A strong research question is almost boringly specific. If someone in another school read it, they should be able to picture your experiment without asking you a single thing. There are four pieces, and all four have to be there.
Assembled, those four rows read: “What is the effect of water temperature (20–60 °C) on the mass of potassium nitrate that dissolves in 25.0 g of distilled water?”
Weak question
Why it fails
Stronger version
How does temperature affect rate?
No chemicals, no range, “rate” of what?
What is the effect of temperature (20–60 °C) on the initial rate of reaction between 1.00 mol dm–3 HCl and calcium carbonate chips?
Which antacid is best?
“Best” is not measurable. Cheapest? Fastest? Strongest?
How does the mass of HCl neutralised per gram compare across four brands of antacid tablet?
How do concentration and temperature affect rate?
Two independent variables at once — you cannot tell which caused what
Pick one. Hold the other constant and say how.
Is vinegar acidic?
Already known, and the answer is one word
How does the concentration of ethanoic acid differ between three types of vinegar, found by titration?
The “two variables at once” mistake is the most common one I see. It feels ambitious, but it makes your data impossible to interpret — if the rate changes, you genuinely cannot say which of your two changes caused it. One variable, explored properly, always scores better.
Doing the background research
Reading around your idea is not decoration. You are hunting for three specific things, and it is worth knowing what they are before you start.
🧩 What you are actually looking for
The theory that explains the relationship. Collision theory, Le Chatelier, bond enthalpies, intermolecular forces — whichever one your question sits on. This becomes the “because” in your hypothesis.
A published value to compare with. A literature enthalpy change, a solubility curve, a known concentration. Without one you can only say “my results went up”, which is a thin conclusion.
A method that already works. Someone has almost certainly measured something similar. Borrow the technique, then change the variable you care about.
Where to look, roughly in order of how much you should trust it: the IB data booklet (values you are allowed to quote in exams), your textbook, established chemical databases for physical data, then reputable university or government pages. Random blogs and revision sites are fine for getting your bearings, but do not build a justification on them.
Research also saves you from dead ends. Five minutes reading might tell you that the reaction you picked takes three days at room temperature, or needs a chemical your school does not stock. Far better to find that out now than after two lab sessions.
Writing a hypothesis with chemistry in it
A prediction says what will happen. A hypothesis says what will happen and why. That second half is what separates a good hypothesis from a coin flip, and it is where the marks live.
Hypothesis structure
If what you change, then what happens to what you measure, because the chemistry
“If the concentration goes up, the rate will go up” is a prediction. It could have been made by someone who has never studied chemistry. Add “…because there are more acid particles in the same volume, so collisions between reacting particles happen more often” and it is a hypothesis.
WORKED EXAMPLE
Taking a broad idea all the way to a hypothesis
A student is interested in why sugar and salt seem to dissolve differently in hot and cold water. Take this from a vague interest to a research question and hypothesis.
Step 1: What did the reading turn up?
Solubility curves exist for most salts. Potassium nitrate has a very steep one, and dissolving it is endothermic.
Step 2: Pick one salt and one measurable outcomeChange: water temperature. Measure: mass of KNO₃ that will dissolve.Step 3: Write the question with a range“What is the effect of water temperature (20–60 °C, in 10 °C steps) on the mass of potassium nitrate that dissolves in 25.0 g of distilled water?”Step 4: Hypothesis with the chemistry attached
If the water temperature is raised, then more KNO₃ will dissolve, because dissolving it is endothermic, so by Le Chatelier’s principle heating shifts the dissolving equilibrium towards the dissolved ions.
One variable, real numbers, a reason rooted in theorya quick check: roughly 8 g at 20 °C rising to nearly 28 g at 60 °C — easily weighable
WORKED EXAMPLE
Repairing a broken research question
A student writes: “How does surface area affect the speed of a reaction?” Identify what is wrong with it and rewrite it.
Fault 1: no chemicals named
Surface area of what, reacting with what?
Fault 2: no range
“Surface area” is not a set of values you can put on an axis.
Fault 3: “speed” is not measurable as writtenYou need a quantity: volume of gas per second, or mass lost per second.Rewrite with all three fixed“What is the effect of the particle size of calcium carbonate (large chips, small chips, powder) on the initial rate of CO₂ production, measured as mass loss per second, when reacted with 50.0 cm³ of 1.00 mol dm⁻³ HCl?”Chemicals named, values listed, outcome measurableit is longer — good research questions usually are
WORKED EXAMPLE
Turning a prediction into a hypothesis
A student predicts: “Powdered calcium carbonate will react faster than chips.” Add the justification that makes it a hypothesis.
Step 1: Which theory covers this?
Collision theory — rate depends on how often particles collide with enough energy.
Step 2: Link the change to that theorySame mass, smaller pieces → far more exposed surface.Step 3: Say what that does to collisions
More of the solid is available for acid particles to hit, so the frequency of successful collisions per second rises.
Step 4: Write it in the standard form
If the calcium carbonate is powdered rather than in chips, then the initial rate will be higher, because the greater surface area exposes more particles to the acid, increasing the frequency of successful collisions.
Prediction + mechanism = hypothesisif you cannot name the theory behind your prediction, go back and read some more
💡 Exam tip
Write your research question as a question, ending in a question mark. “Investigating rates of reaction” is a title, not a research question.
Put the range in the question itself. It shows you have already thought about whether the experiment is doable.
A comparison — two acids, two alcohols, three brands — usually gives you more to discuss than a single measurement.
Say how you will measure the dependent variable, not just what it is. “Rate” becomes “volume of gas collected in the first 30 seconds”.
Do a rough feasibility sum before committing: how many runs, how long each, how much of each chemical.
If your question can be answered by looking something up, it is not an investigation.
⚠ Common mix-up
Choosing a topic instead of a question. “Something about equilibrium” gives you nothing to change and nothing to measure.
Two independent variables. Ambitious, and it makes the results uninterpretable.
Confusing a prediction with a hypothesis. No “because”, no hypothesis.
Justifying with common sense instead of chemistry. “It will be faster because hot things are faster” is not a scientific reason.
Using words like “best”, “better” or “good” in a research question. None of them can be measured.
Refusing to change the question after research. Finding out your first idea will not work is the research doing its job.
Picking something so unusual that no comparison value exists. With nothing to compare against, your evaluation has very little to say.
Up next: Designing Investigations — turning that question into a method someone else could follow exactly, with a justified range, sensible repeats and the right apparatus.
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