New
New
Year 10
AQA
Higher

Heating curves: practical

I can collect data reliably and represent it appropriately.

New
New
Year 10
AQA
Higher

Heating curves: practical

I can collect data reliably and represent it appropriately.

Lesson details

Key learning points

  1. An investigation can measure the temperature change through continuous heating of a substance.
  2. Heating curve observations are best presented in a table and graphically.
  3. Reliable data can be collected by taking repeat measurements, identifying anomalies and calculating a mean.
  4. Heating curves can be used to determine the melting point of a substance.

Common misconception

Pupils can often think that when the temperature is not increasing, i.e. at a change of state, that the experiment is 'not working'.

Question students whilst circulating the class about what they would expect to see and try to get them to imagine what is happening to the particles. Use the heating curve to explain why the temperature did not increase during state changes.

Keywords

  • Independent variable - the single variable that is changed in an investigation

  • Dependent variable - the single variable that is measured or observed in an investigation

  • Control variable - all variables, other than the independent and dependent variables, that are kept the same in an investigation

Practice the experiment before you teach this lesson to ensure that the necessary time needed to perform the practical has been estimated. This practical could also be carried out as a cooling curve where pupils melt a sample and allow it to cool measuring its temperature of over a period of time.
Teacher tip

Equipment

bunsen burner, tripod, beaker for water bath, gauze, heat resistant mat, clamp and stand, thermometer, boiling tube, substances to heat e.g. stearic acid, salol, graph paper

Content guidance

  • Risk assessment required - equipment

Supervision

Adult supervision required

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of these are essential things you need to do when planning an experiment?
Correct answer: work out which safety precautions are needed
complete a trial run of the experiment
Correct answer: if needed, prepare a table to record results
put equipment together
Correct answer: map out a step-by-step method
Q2.
Put the following steps in order to describe a method for collecting data to plot a heating curve of the solid substance shown in the boiling tube. Begin with 'collect all the equipment'.
An image in a quiz
1 - collect all the equipment on the equipment list
2 - set up all the equipment as shown, with the Bunsen not yet heating the water
3 - record the initial temperature of the substance
4 - start the timer and start heating with the Bunsen at the same moment
5 - record the temperature every 30 seconds until the water is boiling
6 - note times and temperature at which the solid substance starts to melt
7 - leave the equipment to cool before dismantling it and tidying away
Q3.
What is a gauze used for? On this diagram, it is represented by the wavy line between the tripod and the beaker.
An image in a quiz
Correct answer: to spread out the heat over the base of the beaker
to make sure the Bunsen burner cannot touch the tripod
to make the platform of the tripod a square shape
to prevent the water bath from overheating
Correct answer: to make the beaker more stable and less likely to fall
Q4.
A table for results should include columns to record independent and dependent variables and and other necessary information. The dependent variable is usually recorded in the column.
Correct Answer: second, 2, 2nd
Q5.
Which safety precautions are needed for a heating curve experiment, in which a solid is melted in a water bath, with its temperature measured over time?
Correct answer: placing the equipment in the middle of the bench
Correct answer: standing up during the experiment
opening windows to remove fumes
Correct answer: putting all stools underneath the bench
Correct answer: wearing eye protection
Q6.
When transferring information from a results table to a graph, which variable should be plotted along the x-axis?
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control variable
dependent variable
Correct answer: independent variable

6 Questions

Q1.
The table shows data from a heating curve experiment. What is the main reason why it is helpful to plot a graph of these results?
An image in a quiz
it shows the whole range of results
Correct answer: it shows patterns in the results
it shows the temperature change every 30 seconds
it shows the temperature change between any two times
Q2.
Match the key terms to their definitions.
Correct Answer:independent variable,variable that you change or select values for

variable that you change or select values for

Correct Answer:dependent variable,variable that you measure or observe to get your results

variable that you measure or observe to get your results

Correct Answer:control variable,variable that must remain the same throughout an investigation

variable that must remain the same throughout an investigation

Correct Answer:anomalous result,value that does not fit the pattern of the results

value that does not fit the pattern of the results

Correct Answer:mean value,average calculated by adding all values, dividing by number of results

average calculated by adding all values, dividing by number of results

Q3.
What can you do to improve the reliability of a set of results?
Correct answer: calculate a mean average for each measurement
Correct answer: cross out any anomalous results and don't use them
cross out the biggest value from each set of repeat measurements
Correct answer: repeat the experiment to check measurements
plot a graph of the results
Q4.
The table shows data from a heating curve experiment. What would be useful other information to record for each measurement?
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Correct answer: whether or not the substance is melting
the temperature of the laboratory
the type of Bunsen flame
Correct answer: the state of matter of the substance
the names of the pupil(s) you are working with
Q5.
The image shows a results table from either a heating or a cooling curve experiment, and from either a pure substance or a mixture. Which of the following statements is true?
An image in a quiz
this is a cooling curve for a mixture
this is a cooling curve for a pure substance
Correct answer: this is a heating curve for a mixture
this is a heating curve for a pure substance
Q6.
Considering the data in the table at the start of the experiment, which graph would be the most likely to represent the results for the whole experiment?
An image in a quiz
An image in a quiz
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz

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