AQA · GCSE · Chemistry
Course version: 8462 · Version from Sept 2018
Required practical 4: investigate the variables that affect temperature…
Full specification wording
Energy transfer during exothermic and endothermic reactions: Required practical 4: investigate the variables that affect temperature changes in reacting solutions such as, eg acid plus metals, acid plus carbonates, neutralisations, displacement of metals.
In Required practical 4, you investigate variables that affect temperature changes in reacting solutions.
Checked against the AQA 8462 specification (opens in a new tab) on .
- Point 12 of 12
- 4 key terms
Study notes
From the checked teaching notes for this specification point.
The idea
In Required practical 4, you investigate variables that affect temperature changes in reacting solutions. Suitable reactions include acid plus metals, acid plus carbonates, neutralisation and displacement of metals. You measure the temperature change of the solution before and after reaction, then vary one factor at a time, such as concentration, volume, particle size or the metal used. For example, react different concentrations of hydrochloric acid with magnesium and record the maximum temperature rise. Control other variables to make the comparison fair. The practical develops skills in measuring temperature, controlling variables, recording data and drawing conclusions about energy transfer.
What earns the marks
- Choose a reacting solution system such as acid plus metal, acid plus carbonate, neutralisation or displacement.
- Measure the initial temperature of the solution before adding the second reactant.
- Measure the maximum or final temperature after the reaction and calculate the temperature change.
- Vary one independent variable at a time, such as concentration, volume, particle size or identity of metal.
- Control other variables to ensure a fair test, for example using the same volume and starting temperature.
- Record results in a suitable table and use them to identify patterns or draw conclusions.
Common mistakes and how to put them right
Changing more than one variable at once.
Put it right by altering only the chosen independent variable and keeping others constant.
Failing to record the initial temperature.
Put it right by measuring and noting the starting temperature before mixing.
Using different volumes or concentrations unintentionally.
Put it right by measuring volumes accurately and using the same conditions for each trial.
Exam tips
- Write a clear plan that identifies the independent, dependent and control variables.
- Present results in a table with units and calculate temperature change consistently.
- When drawing conclusions, refer to the data and explain how the variable affected the temperature change.
Try the lesson
The start of the Energy transfer during exothermic and endothermic reactions: Required practical 4: investigate the variables that affect temperature changes in reacting solutions such as, eg acid plus metals, acid plus carbonates, neutralisations, displacement of metals. lesson, made from checked teaching notes for this specification point.
Have a go first
A student investigates the temperature change when dilute hydrochloric acid reacts with sodium hydroxide solution. Which method will give the most accurate measurement of the temperature change?
Listen
In Required practical 4, you investigate variables that affect temperature changes in reacting solutions. Suitable reactions include acid plus metals, acid plus carbonates, neutralisation and displacement of metals. You measure the temperature change of the solution before and after reaction, then vary one factor at a time, such as concentration, volume, particle size or the metal used. For example, react different concentrations of hydrochloric acid with magnesium and record the maximum temperature rise. Control other variables to make the comparison fair. The practical develops skills in measuring temperature, controlling variables, recording data and drawing conclusions about energy transfer. A strong answer earns marks for these points. Choose a reacting solution system such as acid plus metal, acid plus carbonate, neutralisation or displacement. Measure the initial temperature of the solution before adding the second reactant. Measure the maximum or final temperature after the reaction and calculate the temperature change. Vary one independent variable at a time, such as concentration, volume, particle size or identity of metal. A common slip: Changing more than one variable at once. Instead, altering only the chosen independent variable and keeping others constant. Exam tip: Write a clear plan that identifies the independent, dependent and control variables.
Key words
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Required practical skills
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Variables and fair testing
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Temperature change measurement
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Energy transfer in reactions
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See every definition
- Required practical skills
- Skills in measuring temperature, controlling variables, recording data and drawing conclusions about energy transfer, developed by investigating variables that affect temperature changes in reacting solutions.
- Variables and fair testing
- Varying one independent variable at a time, such as concentration, volume, particle size or identity of metal, while controlling other variables to ensure a fair test.
- Temperature change measurement
- Measuring the initial temperature of the solution before adding the second reactant, then measuring the maximum or final temperature after the reaction and calculating the temperature change.
- Energy transfer in reactions
- Drawing conclusions about energy transfer from recorded results, using them to identify patterns or explain how a chosen variable affected the temperature change.
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