Activity

Iodised salt

In this activity, students test a variety of commercially available table salts for the presence of iodine – a micronutrient essential for health and wellbeing.

By the end of this activity, students should be able to:

  • recognise the difference in structural terms between the element iodine and one of its ionic forms known as iodide ion

  • describe a simple chemical test to detect the presence of iodine in iodised salt and explain in simple terms the chemistry underlying the test

  • effectively manipulate simple laboratory equipment

  • successfully test commercially available table salts for the presence of iodine

  • demonstrate an understanding of the role iodine plays in the body.

Tube of iodine in a beaker showing purple color of its vapor

The element iodine

Iodine, a solid at room temperature, is element number 53 on the periodic table. When gently heated it sublimes into a purple vapour as seen here. Iodine is an essential element in the diet, too little can result in the medical condition goitre. Using iodised salt is one way of making it available to the body.

Rights: Pierre Joliveau

Download the Word file (see link below) for:

  • introduction/background notes

  • what you need

  • what to do

  • student worksheet.

Published: 18 March 2011