Calorimetry can be used to measure a reaction's energy change indirectly.
Calorimetry data can be used to calculate the mass of alcohol needed to cause a 1°C rise in temperature of the water.
An alcohol that causes a 1°C temperature rise when the least amount is combusted is releasing the most energy.
The energy change of combustion for a variety of alcohols can be compared to the molecular formula of each alcohol.

Common misconception

Forgetting to measure the initial mass of the burner and initial temperature of the water.

Emphasise the importance in remembering to measure this data when writing a method for this practical.

Keywords

Alcohols - Alcohols are a homologous series that contain the -OH functional group.
Combustion - Combustion is an exothermic reaction where a substance reacts with oxygen.
Calorimetry - Calorimetry is an experiment that can be used to measure the energy released from a fuel such as alcohol.
Independent variable - The independent variable is the single variant that is changed in an investigation.

Demonstrate how the equipment should be set up, and how heat loss to the surroundings can be minimalised.

Teacher tip

Equipment

Alcohol burners and calorimetry apparatus.

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).

Video

Skip video

Worksheet

Download worksheet

Skip worksheet

Starter quiz

Download starter quiz

6 Questions

Q1.

Name the alcohol shown in the image

Correct Answer: butanol, butan-1-ol

Q2.

What hazard symbol would you expect to find on an alcohol burner in the lab?

Correct answer: flammable

radioactive

compressed gas

harmless

explosive

Q3.

Which variable is defined as the single variant that is changed in an investigation.

dependent variable

Correct answer: independent variable

control variable

Q4.

What is the molecular formula of propanol?

Correct answer: C₃H₇OH

C₃H₈O

C₃H9O

C₂H₇O

C₂H₈O

Q5.

In a calorimetry experiment the initial temperature of water is 23ᵒC. The water temperature rises to 55ᵒC. What is the temperature change?

Correct answer: 32

Q6.

What number needs to be placed in front of the CO₂ to balance this equation? C₄H₉OH + 6O₂ → _CO₂ + 5H₂O.

Correct answer: 4

Exit quiz

Download exit quiz

6 Questions

Q1.

Which of the following statements about the combustion of alcohols are true?

Correct answer: The longer the carbon chain in an alcohol, the more energy is released.

The longer the carbon chain in an alcohol, the less energy is released.

Correct answer: Butanol has a longer carbon chain than methanol.

Butanol has a shorter carbon chain than methanol.

Q2.

What is the name of an experiment that can be used to measure the energy released from a fuel such as alcohol?

Correct Answer: calorimetry

Q3.

2 g of methanol, ethanol and propanol were combusted in a calorimetry experiment. Which fuel will cause the greatest temperature rise in 50 cm³ of water in the calorimeter?

methanol

ethanol

Correct answer: propanol

Q4.

Using the data of the mass needed to cause a temperature rise. Which alcohol releases the most energy during combustion?

methanol 0.043 g/°C

ethanol 0.041 g/°C

Correct answer: propanol 0.037 g/°C

Q5.

Calculate the mass of butanol needed to produce a 1°C temperature rise when 1.3 g of butanol produced a 49°C rise in temperature of 100 cm³ of water.

63.7 g

37.69 g

Correct answer: 0.027 g

0.77 g

Q6.

Calculate the mass of propanol needed to produce a 10°C temperature rise when 1.45 g of propanol produced a 46°C rise in temperature of 100 cm³ of water.

0.021 g

0.21 g

0.0315 g

Correct answer: 0.315 g

69 g

Additional material

Download additional material

We're sorry, but preview is not currently available. Download to see additional material.