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What makes a substance acidic?

Description

These experiments can be used to show students that the familiar acidic (and alkaline) properties of some substances require the presence of water.

Credits

:
This is an experiment from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry.
what-makes-a-substance-ac...

 


 


Apparatus Chemicals

Goggles for all participants

For the demonstration in Steps a–d, the teacher will require:

Boiling tubes, 2 (must be dry) (Note 1)

Rack to hold boiling tubes

Teat pipette (must be dry) (Note 1) – not needed if the ethanoic acid is provided in a dropper bottle

Glass rod

pH colour chart

Universal indicator paper, 2 small strips (must be dry) (Note 2)

For steps e–h each group of students (or the teacher) requires:

Test-tubes, 4 (all test-tubes must be dry). Use boiling tubes if continuing as a demonstration

Test-tube / boiling tube rack

Spatula

Forceps

Universal indicator paper, 4 small strips

Access to Universal indicator pH colour chart

For the demonstration in Steps a–d, the teacher will require:

Magnesium ribbon, 2 cm lengths

Pure ethanoic acid (glacial acetic acid) (CORROSIVE), 10 cm3 in a small dropper bottle

Tap water (ensure pH = 7)

For steps e–h each group of students (or the teacher) requires:

Universal indicator solution (HIGHLY FLAMMABLE) in a small dropper bottle

Small containers of:

Tartaric acid crystals (IRRITANT)

Bismuth nitrate crystals (OXIDISING, IRRITANT)

Hydrated aluminium chloride (IRRITANT)

Magnesium ribbon, 1 cm lengths (use 2 cm lengths if continuing to demonstrate), 4

Tap water (ensure pH = 7)

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

 

 


 




 





These experiments can be used to show students that the familiar acidic (and alkaline) properties of some stubstances require the presence of water.

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.