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A1.11 · Communicate chemistry procedures, results, and conclusions clearly

Learn to communicate chemistry procedures, results, and conclusions clearly through clear examples and targeted practice.

Ontario Grade 12 Chemistry

Scientific Investigation Skills and Career Exploration

Procedures, results, and conclusions in Grade 12 chemistry

A chemistry investigation is useful only if another person can understand what was done and what the evidence shows. Clear communication lets a reader follow the procedure, interpret the results, and judge whether the conclusion is supported. This lesson focuses on that skill: reporting chemistry procedures, results, and conclusions clearly. It does not ask you to perform a particular investigation.

What you will learn

Explain why clear communication matters in a chemistry investigation.
Distinguish a procedure, a result, and a conclusion.
Describe observations and measurements accurately, with suitable units.
Write a conclusion that answers the investigation question and is supported by results.

1. Start with the purpose and the observable evidence

Before writing, identify the investigation question. It tells the reader what the procedure and results are meant to address. A focused question might ask how an indicator appears in several solutions. A purpose statement then says what will be compared or measured, without claiming a result in advance.

In chemistry, begin with what can be observed or measured. An observation is a record of something detected by the senses or an instrument. Examples include a colour change, a measured temperature, or a volume reading. Separate what you observed from what you think caused it. “The solution became cloudy” reports an observation. “A solid formed” is an interpretation unless the procedure or additional evidence supports it.

A measurement is an observation expressed with a number and a unit. A unit tells the reader what the number measures. For example, a volume of

5.0\,\mathrm{mL}

is more informative than “5.0,” and a temperature of

22.4\,^{\circ}\mathrm{C}

is more useful than “22.4.” Record measurements as they are taken, rather than relying on memory.

A particle model can help explain an observation, but label it as an explanation rather than presenting it as something directly seen. For instance, a colour change may be observable, while a description of changes among particles is a model-based interpretation. Use the simplest explanation needed for the investigation and connect it to the recorded evidence.

State the question or purpose before describing what the investigation found.
Keep observations distinct from interpretations.
Give measured values with units.

2. Write a procedure another person can follow

A procedure is an ordered description of what was done. A clear procedure gives enough detail for another student to repeat the investigation in a similar way. Name the materials or solutions that matter, explain the order of the actions, and include relevant amounts, times, or conditions when they are known.

Use specific action words. “Add three drops of indicator to each sample” gives more useful information than “use some indicator.” Identify samples consistently, such as A, B, and C, and use those same labels in the results. If the procedure includes a comparison, make clear what is kept the same and what is changed. These details help a reader see whether the comparison is fair.

Report what was actually done, not what should have been done. If a step was changed or a measurement was missed, state that clearly. Do not quietly replace an uncertain observation with a more definite one. A reader needs an accurate account to judge the evidence.

Safety directions are part of a useful procedure when they affect how the work is carried out. Include the relevant precautions and disposal instructions supplied for the investigation. Do not invent safety requirements or imply that a procedure was performed when it was only proposed.

Put actions in the order they occurred.
Include enough detail to make the procedure understandable and repeatable.
Report changes or missing information honestly.

3. Present results before drawing conclusions

Results are the observations and measurements collected during an investigation. Present them in a format that makes comparisons easy. A small table can help when several samples have the same kinds of results. Give every column a clear heading, include units for measured quantities, and use the sample labels from the procedure.

Use precise wording for qualitative results. Qualitative results describe qualities, such as colour or whether bubbles were visible. Quantitative results use numbers and units. Do not report more digits than the measuring tool or supplied data support. If a value was not measured, do not fill in a plausible number.

A conclusion answers the investigation question using the results. It should identify the relevant pattern or comparison, then explain what that pattern supports. Do not claim that results prove more than they show. If observations are uncertain or limited, say so. A conclusion should not introduce a new measurement or a result that was absent from the results section.

Keep the evidence and the explanation connected. For example, point to a recorded colour difference before stating what it suggests about the samples. If the evidence does not distinguish two possibilities, acknowledge that limit rather than choosing one without support.

Organize results so the reader can compare samples.
Use units for measurements and preserve the precision of the data.
Make conclusions answer the question and match the evidence.

4. Revise for accuracy and clarity

A clear report uses consistent names, labels, and units from beginning to end. Check that a sample called B in the procedure is still called B in the results and conclusion. Check that a number has not lost its unit and that recorded values have not been altered while being copied.

Use sentences that make the relationship between evidence and conclusion easy to follow. Avoid vague phrases such as “it changed a lot” when a specific observation is available. Avoid unsupported claims such as “the test was perfect.” Instead, describe the evidence and any known limitation directly.

Before submitting a report, ask whether a reader can identify the question, repeat the procedure, locate the results, and see how those results support the conclusion. If not, revise the missing part. Clear communication is not decoration added after the chemistry; it is how the investigation’s evidence can be understood and evaluated.

Use consistent sample labels and units.
Replace vague statements with specific evidence.
Check that each conclusion is supported by reported results.

Worked example

Turning practice data into a clear report

Practice task: Prepare a short report for an indicator comparison. The following invented practice observations are supplied for learning how to communicate results; they are not results from an investigation performed for this lesson. Sample A appeared red after two drops of indicator. Sample B appeared green after two drops. Describe a suitable procedure, report these results, and write a conclusion that does not claim more than the evidence supports.

Identify what the data can show
The supplied evidence is qualitative: it records the colours seen, not numerical measurements. The task does not identify the solutions or state what the indicator colours mean. Therefore, the report can compare the observed colours, but it should not assign chemical properties to either sample.
State a repeatable procedure
A suitable procedure uses the same stated indicator amount for both samples and preserves the sample labels. This describes how the comparison could be carried out; it does not claim the procedure was performed. The volume of each sample is not supplied, so do not invent one.
Report the observations
Present each supplied observation under its sample label. No units are needed for colour descriptions. Keeping the wording direct makes the comparison easy to check.
Draw a limited conclusion
The evidence supports the conclusion that the two samples showed different observed colours under the stated conditions. Without information about the solutions or the indicator’s meaning, a stronger chemical interpretation is not supported.

Answer: Procedure: Label two sample containers A and B. Add two drops of the indicator to each sample. Record the colour observed in each container. This is a proposed procedure for the practice task, not a claim that it was performed. Results: Sample A appeared red. Sample B appeared green. Conclusion: The supplied observations show that the samples appeared different colours after the same stated number of indicator drops. The evidence supports a comparison of their appearances, but it does not identify the samples or establish what chemical property caused the colour difference.

Check: The conclusion refers only to the supplied colour observations. It does not invent sample identities, measurements, or an explanation that the data cannot support.

Common mistakes and how to avoid them

Writing an interpretation as if it were directly observed.

Correction: Record the observable evidence first, then identify any explanation as an interpretation supported by that evidence.

Leaving units off measured values or adding digits that were not measured.

Correction: Include the appropriate unit and report only the precision supported by the measurement or supplied data.

Making a conclusion broader than the results.

Correction: Answer the investigation question using the specific evidence collected, and state limits when the evidence is incomplete.

Writing a procedure with vague directions such as “add some” or “wait a while.”

Correction: Give specific amounts, order, and timing when those details are known. Do not invent details that were not supplied.

Lesson summary

A clear chemistry report explains its purpose, procedure, results, and conclusion.
Record observations and measurements accurately; include units with measured values.
Use consistent labels and enough procedural detail for another person to understand the work.
Draw conclusions from reported evidence and do not claim that a proposed procedure was performed.

Check your understanding

Question 1

A student records a temperature as 24.6 but does not include a unit. What is the clearest revision if the temperature was measured in degrees Celsius?

24.6
24.6 °C
about 25
A warm temperature

Show answer and explanation

24.6 °C

The number and unit together identify the measured quantity and its scale. The other choices omit the unit, reduce the precision, or replace the measurement with a vague description.

Question 2

A procedure was proposed, but no experiment was carried out. Which statement communicates this accurately?

The samples changed colour during the test.
The results confirmed the prediction.
The procedure could be used to compare the samples.
The investigation showed that sample A was different.

Show answer and explanation

The procedure could be used to compare the samples.

This describes a proposed procedure without claiming that observations or results were obtained.

Key terms

Observation: A record of something detected by the senses or an instrument.
Measurement: An observation reported with a number and a unit.
Procedure: An ordered description of the actions used to carry out an investigation.
Result: An observation or measurement collected in an investigation.
Conclusion: A statement that answers an investigation question using the results.
Qualitative: Describing a quality, such as colour, rather than giving a numerical measurement.
Quantitative: Expressed using a number, usually with a unit for a measurement.

Continue through SCH4U

View the complete SCH4U Ontario Grade 12 Chemistry curriculum and lessons

About this lesson and its review

Published by DoAssignment. This reviewed lesson follows Ontario Grade 12 Chemistry (SCH4U), expectation A1.11. It is a study resource, not an official curriculum publication.

Before publication, content is checked for structure, mathematical or chemical notation, calculations, course boundaries, and readability. Errors can still occur, so corrections are welcomed.

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