Science
Dissolving sugar: scientific investigation and report
Plan a sugar-dissolving investigation, record repeated times and write a conclusion supported by the results. Three pupil pages cover variables, hypothesis, method, data, graphing and evaluation. The companion checks methods and marking while leaving the observed trend open; the teacher approves the practical conditions before use.
Compare the apparatus for different water temperatures. The full investigation gives teacher-led safety and measurement instructions.
Read the complete materialRead the material
Plan a sugar-dissolving investigation, record repeated times and write a conclusion supported by the results. Three pupil pages cover variables, hypothesis, method, data, graphing and evaluation. The companion checks methods and marking while leaving the observed trend open; the teacher approves the practical conditions before use.
Pupil worksheet. Use the preview for diagrams and layout.
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NAME CLASS DATE LEARNING GOAL I can plan and carry out a fair test, then use my results to answer a scientific question. SUCCESS CRITERIA I can name the independent, dependent and control variables. I can write a hypothesis using If ... then ... because ... I can calculate a mean and plot my results on a graph. I can write a conclusion backed by evidence and suggest improvements. cool warm hot OUR QUESTION Does the temperature of water affect how quickly sugar dissolves? You will add the same mass of sugar to water at different temperatures, stir it the same way each time and time how long it takes until no crystals are left. 1 Identify the variables 4 marks Remember: you change the independent, measure the dependent and keep the controls the same. 2 Write a hypothesis 3 marks Predict what will happen and give a scientific reason. Use the frame and the word bank. If then because WORD BANK temperature increases particles move faster energy collide dissolve Check it: does yours name both variables and give a reason about particles? SCIENCE AGES 11 TO 14 LAB REPORT Dissolving sugar Plan a fair test, collect data and write it up like a real scientist. I INDEPENDENT VARIABLE The one thing I change on purpose: The values I will use: D DEPENDENT VARIABLE The thing I measure: Its unit and the instrument I use: C CONTROL VARIABLES Things I keep the same (one is done for you): 1. the mass of sugar (5 g) 2. 3. Pupil activity | Page 1 of 3
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3 Equipment 250 cm³ beaker measuring cylinder thermometer stopwatch granulated sugar balance and spatula stirring rod eye protection STAY SAFE Wear eye protection the whole time and report any spill straight away. Use water no hotter than your teacher allows. Your teacher fills hot water for you. 4 Method 3 marks Some steps are written for you. Complete steps 3, 5 and 7 so another scientist could repeat your test exactly. 5 Results and observations 6 marks Record every time in whole seconds, then work out the mean for each temperature. Water temp. (°C) Time for sugar to dissolve (s) Mean time (s) Repeat 1 Repeat 2 Repeat 3 20 30 40 50 60 WORKED EXAMPLE: THE MEAN mean = (R1 + R2 + R3) ÷ 3 Times of 48, 52 and 50 s: 48 + 52 + 50 = 150, then 150 ÷ 3 = 50 s. DISSOLVING SUGAR DOING THE EXPERIMENT Method, results and observations ! Measure 100 cm³ of water with the measuring cylinder and pour it into the beaker. 1 Put the thermometer in the water and record the starting temperature. 2 Weigh out the sugar: how much, and how? 3 Tip all the sugar into the water and start the stopwatch at the same moment. 4 How will you stir, so it is the same every time? 5 Stop the stopwatch when you can no longer see any sugar crystals. Record the time in seconds. 6 How will you make your results repeatable, and what changes next? 7 OBSERVATIONS Where did the crystals go? Any swirls? Did any repeat look odd? Retain all readings. Flag unusual results, investigate and repeat. Exclude only with a stated justified reason; report its effect. Use an accessible working position approved by the teacher; keep hot beakers stable and away from edges. Pupil activity | Page 2 of 3
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6 Draw a graph 4 marks 0 10 20 30 40 50 60 70 Temperature of water (°C) Mean time to dissolve (s) The x-axis is done. Choose a scale for the y-axis and write the numbers on the tick marks. Even y-axis scale using over half the grid Each mean plotted as a neat cross (×) Describe the pattern your graph shows: 7 Conclusion: claim, evidence, reasoning 3 marks C Claim As the temperature of the water increases, the time ... E R Reasoning This happens because the water particles ... 8 Evaluate your investigation 4 marks GO FURTHER s. Tell a partner why this How confident do you feel? Not yet Getting there Got it DISSOLVING SUGAR WRITING THE REPORT Graph, conclusion and evaluation SOURCES OF ERROR What made your results less accurate or less repeatable? IMPROVEMENTS How would you fix each one next time? Best-fit line/curve if supported Evidence: At ___ °C the mean was ___ s; at ___ °C it was ___ s. Estimate from graph at 45 °C: Pupil activity | Page 3 of 3
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Teacher companion Dissolving sugar: scientific investigation and report Variables, 4 marks Independent: chosen starting water temperature, °C (1). Dependent: time until no sugar crystals visible, s (1). Two suitable controls, 1 each: sugar mass/type, water volume, beaker, stirring method/rate or endpoint judgement. Hypothesis, 3 marks Award a prediction (1), relationship between variables (1) and plausible particle explanation (1). A prediction is not a required observed result. Method, 3 marks Complete steps specify 5 g sugar measured on a balance (1), consistent stirring method/rate (1), and three repeats at each approved temperature with controlled water volume and new measured portions (1). Use100 cm³ water, record actual temperatures and times. Local teacher approves maximum temperature, equipment, accessible positions and supervision before a practical. Results, 6 marks Suitable headings/units, all raw readings, three repeats per temperature, controlled method recorded, correctly calculated means, unusual readings investigated and documented: one mark each. Example48,52,50 gives50 s. Do not delete an unusual reading automatically. Report a justified exclusion transparently, retaining raw data and showing its effect. Graph, 4 marks Suitable even scales (1), labelled axes/units (1), accurately plotted means (1), appropriate trend representation supported by the actual data (1). A straight line, curve or no clear trend can be defensible; no compulsory curve shape. Interpolation at45°C requires a supported trend within measured temperatures; extrapolation to90°C is unsupported. Conclusion, 3 marks Data-consistent claim (1), two actual results with units (1), plausible explanation with limits (1). Accept decreasing, increasing or unclear trend when honestly supported. Repeats assess consistency and help investigate anomalies; they do not prove accuracy. Evaluation, 4 marks Two specific limitations paired with two practical improvements, one mark each. Examples include water cooling/start-end temperature checks, endpoint judgement/consistent observer and timing or stirring control. Total4+3+3+6+4+3+4=27. No fixed observed trend is promised. Teacher companion | Page 1 of 1
A teaching sequence
Pupils should specify a repeatable fair test, record all raw readings with units, calculate means and represent their actual data. Their conclusion should cite two results and their evaluation should connect two specific limitations with practical improvements.
Compare the apparatus for different water temperatures. The full investigation gives teacher-led safety and measurement instructions.
Read the complete materialPlan a repeatable sugar test
Complete the controls and hypothesis, then fill the method gaps with 5 g sugar, a consistent stirring method and three repeats at each approved temperature. Ask whether another group could repeat the written method.
Could another group repeat your mass, volume and stirring method safely?
Record every observation
Under approved supervision, record actual temperatures, every time and relevant observations. Keep unusual readings, investigate the method and document any repeat or justified exclusion.
Have you retained unusual readings and documented any justified exclusion?
Calculate and graph the means
Calculate means and choose an even graph scale. Plot the results and decide whether a line, curve or no clear trend is supported rather than drawing a required shape.
Does the plotted evidence support a line, curve or no clear trend?
Write a qualified conclusion
Write a data-consistent claim using two results with units. Pair limitations such as cooling or endpoint judgement with an improvement, then review how those limitations affect confidence in the conclusion.
Which two results with units support your claim?
Before you teach
Look for the thinking behind an answer, choose the support your class needs and leave room for an independent response.
What to look for
A useful report retains raw readings and explains its method; the worked 48, 52 and 50 s example gives a 50 s mean. A conclusion may show a decreasing, increasing or unclear trend if the data support it. If a pupil writes the predicted trend regardless, ask which two measured results support the claim.
Give a little support
Use the variable headings and “If… then… because…” frame to rehearse the plan before recording it. Calculate one mean together with units, then plot one point from that mean. Agree accessible recording and working arrangements with the teacher before handling any approved practical equipment.
Take the idea further
Estimate the time at 45°C only if the measured temperatures bracket it and the graph supports interpolation. Explain how the estimate was obtained and why it is less direct than a measurement. Propose a repeat at that approved temperature to test the estimate rather than extending the graph beyond the measured range.
Things to keep in mind
A predicted decrease is not a required result. Repeats assess consistency, not proven accuracy. Local practical approval is required.
Keep the idea. Make it yours.
Bring your topic, learning goal and class context to PLAI™, then review what you create.
Ideas to try with your class
Sample teaching perspectives on what to try, what to adapt and what to watch for.
Meet The Creators
Meet the creators whose teaching interests connect with this template. Find an approach to try with your class.
Arjun Nair
I want pupils to interpret practical data, explain what changed and what they measured, and reconsider their first ideas when observations suggest a better question.
Meet the creator
Sarah Whitcombe
Mangroves, reefs and tropical ecology give us plenty to investigate, so I look for ways to connect the syllabus with what pupils can observe around them.
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Wei Jie Tan
Prediction gives us a useful place to begin: what should happen, why do we expect it and what evidence would help us check?
Meet the creatorDang Thi Thao
I look for ways to make instructions explicit, check understanding without putting anyone on the spot and connect a new idea to examples the group can recognise.
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Dr Anjali Menon
I coordinate Science practicals with the lead technician, linking activity-specific preparation and review with shared laboratory time so the department can notice and respond to gaps early.
Meet the creator
Good Question
This three-page investigation asks pupils to plan a fair test of cool, warm and hot water, name independent, dependent and control variables, take raw readings with units, calculate means, graph actual data and evaluate limitations with improvements.
Book and Biscuit
The learning goal links planning and carrying out a test to using results in an answer. The success criteria give pupils a fuller report sequence than a completed-results worksheet.
After the Bell
Have the teacher approve and supervise the temperature conditions and method before practical work. Model one raw reading with units and one mean calculation, then let pupils plot their own results.
Tea at Breaktime
This sheet does not itself make handling hot water safe or supply a current local risk assessment. Confirm activity-specific controls and supervision, and keep generated or sample values separate from actual class observations.