MYP 10
 
 


Unit 10.4.4 - Combustion of fuels - ethanol

Objectives

  • To determine the molar energy of combustion of ethanol by calorimetry
  • To appreciate that energy losses are the major inaccuracy
  • To evaluate the class data in terms of precision and accuracy
  • To appreciate the meaning of systematic error and random error.

Class activity

Calorimetry is used to measure the temperature change when a spirit burner is used to heat a sample of water in a beaker.

The mass of the spirit burner is measured before and after the experiment.

The mass of water in the beaker is measured.

The energy change in the water is calculated by ΔE = mcΔT

The moles of ethanol burned are found by the mass loss divided by the relative mass of ethanol.

The energy change per mol is calculated by ΔE/mol

The results of the calculations are collated by the teacher and discussed in terms of:

Student follow up

Notes on experimental errors and inaccuracy in exercise books

Assessment

None

Teaching notes

literature value for the enthalpy of combustion of ethanol = 1340 kJ mol-1

Resources

NIST chemistry webbook

Calorimetry animation


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