Indicators and dry ice demonstration

Description

Dry ice is added to indicator solutions. Bubbles and a ‘fog’ are produced along with a gradual colour change. The experiment is a great way to demonstrate neutralisation reactions and pH changes, as well as to highlight that carbon dioxide forms weakly acidic solutions.

Type of Activity

:
demonstration

Audience

:
Teacher

Age Group

:
11 to 18 years

Credits

:
This is an experiment from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry.
indicators-and-dry-ice-de...



Apparatus Chemicals

The teacher requires:

Eye protection

Measuring cylinders (1 dm3), as many as the number of indicators to be used (Note 1)

Expanded polystyrene cool-box to store the dry ice (Note 2)

Tongs or large spoon/scoop for transferring dry ice

Long stirring rod

Gloves (leather or insulated) for handling dry ice

Dry ice, allow 100 g for each indicator

Access to a range of indicator solutions. Suitable ones include:

Universal Indicator

Phenolphthalein

Thymolphthalein

Thymol blue

Phenol red

Bromothymol blue

Dilute ammonia solution and/or dilute sodium hydroxide solution, 0.1 M (IRRITANT)

Refer to Health & Safety and Technical notes section below for additional information.

 






Dry ice is added to indicator solutions. Bubbles and a ‘fog’ are produced along with a gradual colour change. The experiment is a great way to demonstrate neutralisation reactions and pH changes, as well as to highlight that carbon dioxide forms weakly acidic solutions.

ADDITIONAL INFORMATION

This is a resource from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry. This collection of over 200 practical activities demonstrates a wide range of chemical concepts and processes. Each activity contains comprehensive information for teachers and technicians, including full technical notes and step-by-step procedures. Practical Chemistry activities accompany Practical Physics and Practical Biology.

The experiment is also part of the Royal Society of Chemistry's Continuing Professional Development course: Chemistry for non-specialists