MYP 8 Science - Chemistry

MYP 8.5.6: Action of heat on limestone - preparation of limewater

Background

Calcium is found in group 2 of the periodic table just below magnesium.

It is a very common element on the earth, although it is far too reactive to be found on its own. It reacts directly with water and oxygen and many other elements. Calcium is found on earth combined with other elements in the form of limestone and marble, which are both forms of calcium carbonate, CaCO3.

Calcium carbonate is also a major constituent of bones and teeth.

Objectives:

  • To understand the law of conservation of matter
  • To realise that gases may be involved in reactions and that they are often invisible
  • To know that limestone is formed from living organisms
  • To know that limestone is calcium carbonate
  • To know that calcium oxide is quicklime
  • To know that calcium hydroxide is limewater
  • To know that limewater may be used to test for carbon dioxide

Student Activity

Part 1

Balance a marble chip on to the corner of a tripod and heat strongly (safety glasses)

After about 10 minutes, gently pick up the marble chip with some crucible tongs and drop it into a small beaker containing about 50 cm3 of water.

Stir and filter into a small conical flask.

Part 2

Divide the filtrate into three test tubes.

Test tube 1: Add a few drops of universal indicator solution

Test tube 2: Using a clean straw gently exhale your breath several times through the solution. Beware splashing!

Write-up: Criterion B - communication skills

Resources

White Horse Hill

 

Teaching notes

The safety aspects must be discussed. The white powder formed by heating marble is calcium oxide (quicklime), which is corrosive.

 

 


 
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Copyright: 2003 Isis Publication