Neutralization heat
To demonstrate the enthalpy change arising from the neutralization of a strong acid with a strong base.
The science behind this experiment
This experiment illustrates the typical reaction between acids and bases: an exothermic reaction, in which there is an evolution of heat.
Equipment used
- Beaker 50 ml — CHE-002
- Glass rod — PLA-004
- Cylinder 100 ml — MEC-001
- Thermometer — HEA-005
Chemicals and reagents
- Hydrochloric acid — R:34-37 S:26-45
- Sodium hydroxide — R:35 S:26-37/39-45
Questions for students
- Describe what has happened.
What to expect
Every acid base reaction in aqueous solution gives the following neutralization reaction: H3O+ + OH– →2H2O. For which the enthalpy change is ∆H0 = – 55.8 K J mol1; the reaction is therefore exothermic and the system increases its temperature. Na+ + OH– + H3O+ + Cl → Na+ + Cl– + 2H2O. The reaction gives the salt and two molecules of water. The sodium and chloride ions take no part in the reaction and are therefore termed “spectator ions”.
Disposal
Dispose of the solution in the liquid wastes container.
Run this experiment in your classroom
This experiment is part of ATP Volta — a self-contained mobile science lab that turns an ordinary classroom into a working STEM laboratory, with over 200 experiments in physics, chemistry, biology, robotics and engineering. Gali, the AI tutor built into ATP Connect, guides students through each step and answers their questions at the bench.
See the ATP Volta mobile science labTalk to our team