Close
Learn Chemistry is changing
Our new website is coming soon. Find out more

How can hardness in water be removed?

Description

The hardness of temporarily and permanently hard water is tested using soap solution.

Credits

:
This is an experiment from the Practical Chemistry project, developed by the Nuffield Foundation and the Royal Society of Chemistry.
how-can-hardness-in-water...



Apparatus Chemicals

The teacher will require:

Eye protection

Beakers (500 cm3), 3

Bunsen burner

Tripod and gauze

Heat resistant mat

Vacuum filtration apparatus (Note 1)

Ion exchange apparatus (Note 2)

Gas generator for carbon dioxide (Note 3), or a CO2 cylinder

Each student or group of students will need:

Test-tubes, 9

Test-tube rack

Labels, for test tubes

Beaker (100 cm3)

Dropping pipette

Spatula

The teacher will require:

Calcium sulfate solution, 300 cm3(Note 4)

Limewater (IRRITANT), 150 cm3

Sodium zeolite, about 5 g (Note 2)

Marble chips

Dilute hydrochloric acid, 2 M (IRRITANT)

Each student or group of students will need:

Solutions labelled as shown below, 100 cm3 each

A Temporarily hard water*

B Permanently hard water (Note 4)

C Temporarily hard water that has been boiled and filtered*

D Temporarily hard water that has passed through an ion exchange column*

E Permanently hard water that has passed through an ion exchange column*

F Distilled water (or deionised water)

* These are prepared by the teacher in the demonstration part of the experiment

Soap solution in IDA (Industrially Denatured Alcohol) (HIGHLY FLAMMABLE, HARMFUL), 10 cm3 (Note 5)

Sodium carbonate-10-water (IRRITANT), about 1 g

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

 

 








The hardness of temporarily and permanently hard water is tested using soap solution.

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.