Labcaire References

Teaching the Teachers

Teaching the Teachers

(Safe demonstrations of chemical reactions)

by Dr Colin Chambers

“Stimulate a teacher today and you stimulate one hundred children tomorrow”

Editor's note:
Dr Chambers is the Chief Examiner and Chairman of A level specification development for an Examination Board. Chairman of the North West Education Division for the RSC (The Royal Society of Chemistry). Retired Head of Chemistry at Bolton School after 35 years as a teacher of Chemistry

During his career as a Chemistry Teacher he has won the:
- SALTERS' AWARD 1994
- ROYAL SOCIEY OF CHEMISTRY EDUCATION AWARD 1985
- UNIVERSITY OF LIVERPOOL CHEMISTRY DEPARTMENT POTTS MEDAL

Teaching the Teachers

Chemistry is definitely not a subject that can be confined to a textbook and overhead projector! The principles of chemical reactions are much better explained by practical demonstrations, which help to reinforce and illustrate important concepts. However, with over 35 years' experience of teaching chemistry in the classroom, it never ceases to amaze me how many teachers are teaching chemical reactions that THEY themselves have never seen, or do not feel confident enough to conduct safely within the confines of a laboratory. For the past 5 years, I have been involved in a lecturing circuit at schools, colleges and universities around the UK, where I am invited to give practical demonstrations of chemical reactions.

The audiences are diverse, and ages can range from primary school children to secondary school chemistry teachers. The aim of the practicals is not only to make chemistry fun, by creating a memorable visual display, but also to illustrate and explain reactions studied as part of a GCSE or A level examination course.

Many of the more dramatic experiments are often those involving hazardous reagents. As with all experiments conducted within a laboratory, safety must always be uppermost in mind. The majority of school chemistry laboratories have ducted built-in fume cupboards. Teachers rarely use these to demonstrate experiments as they themselves block the view of the students and, as they must work with the fume cupboard door open, neither they nor their students are protected by the door. In addition potentially hazardous chemicals are vented out of the laboratory and straight into the atmosphere. This type of fume extraction is obviously not conducive for use whilst demonstrating chemical experiments as we must all be aware of the effect of our actions on the environment.

A MOBILE SOLUTION

I first came across Labcaire's T400 mobile fume cabinet when I was invited to give practical demonstration at one particular University. Having used it throughout the lecture, I was delighted with the performance of its filter system, which contained all the noxious fumes evolved throughout the chemical reactions. I contacted Labcaire who kindly agreed to loan me the use of a T400 whenever I was required to give a demonstration. The T400 has a number of advantages over the classical ducted fume cupboard:

Mobility
The cabinet is both lightweight and fully mobile, providing safe fume containment in situ.
Mobility also means that one fume cupboard can be used in several laboratories.

All round visibility

With integrated lighting and clear acrylic front, sides and back, both the user and spectator can watch the experiment from all angles.
The demonstrator is able to conduct the experiments safely whilst the clear all round visibility assists teacher, audience interaction and ensures maximum benefit from practical science sessions.

Safe containment
The cabinet is equipped with a large capacity activated carbon filter, has airflows well above those detailed in Design Note 29 and incorporates a low airflow alarm safety feature, so ensuring full compliance to BB88 and COSHH regulations.

Optional features
Other features available for the T400 include the incorporation of a moulded drip cup, bottle trap, gas outlets, and full water and waste services.

As a young teacher I was fortunate to work with an excellent experimental chemist who had a wealth of experience in giving demonstrations I learnt much from him. During my years as a teacher I attended many courses and lectures and saw a large number of wonderful demonstrations. I have used some of these in my own teaching and added others I have devised myself. I believe that it is of vital importance that teachers use demonstrations as a visual teaching aid, but they must do so within a safe environment. Both they and their pupils need to be confident that they are not running the risk of exposure to hazardous chemicals.

The combined benefits of convenience for teachers all round visibility for student, flexibility, safety and low noise make Labcaire's T400 the ideal choice for practical demonstrations in chemistry laboratories.

Many demonstration reactions carried out to illustrate topics in A level courses require the use of concentrated ammonia halogens and concentrated acids. These can only be safely done in a fume cupboard. In addition some spectacular demonstration reactions can also be carried out using a fume cupboard.

These include: