WELCOME

INTRODUCING

STUDENTS ARE GOING TO INTRODUCE THEMSELVES, THEIR SCHOOL AND THEIR COUNTRY.

1st step

Part 1 PEOPLE AND CHEMISTRY
INTRODUCE THE TOPIC
■ Do you have any chemicals/chemical products in your home?
■ What chemicals/chemical products do you have in your home?

2nd step

Part 2 CHEMISTRY IN OUR HOMES



In Parts 1 and 2 students find out more about the many
chemical products which people use in their homes. They also
examine the labelling of these products and learn about the
international symbols for labelling chemical substances.
They have an opportunity to make and test a chemical
product

STEP 3 LIVING WITH CHEMISTRY

STEP 3 LIVING WITH CHEMISTRY
Research by interview, or from secondary sources, to investigate a local story related to chemistry and to discover an example of the importance of chemistry to the local, regional or national economy.

martedì 19 maggio 2009

the history of soap


The manufacture of the soap is one of the most ancient chemical trials of syntesis, but it’isn’t so ancient as that of the production of ethilic alcohol; evidently the men’s aspiration to the cleaning is more recent than their tendency to the drunkenness.
At the Caesar’s time, Teutonis boiled the fat of goat with the potassium hydroxide which was derived from burnt wood. Thanks to this procedure, they effected the same chemical reaction that the modern manufactures of soap apply: the hydrolysis of triglycerides, that produces the salts of carboxylic acids and the glycerine.
Normal soap is usually a mixture of salts of sodium.
The composition and the method of production of the soap can vary: if soap is prepared with olive oil, Marsiglia soap is produced; alcohol can be addedto make the soap transparent; perfumes dyes and germicidies can be asdded too.
Hard soap is produced with sodium salts, on the contrary if potassium salts are used, soft soap is produced.


By Antonella

sabato 9 maggio 2009


Uploaded on authorSTREAM by Stacho

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