5.1 Practical Work
In this syllabus the term "practical work" covers all teachers demonstrations and students' experiments that take place in a school science laboratory. This can occur only in a properly organised and safely run laboratory.
5.2 The Syllabus and Practical Work
The syllabus specifies a number of teacher demonstrations and mandatory student experiments. It is recommended that other practical work should also be used in the teaching of chemistry. Additional teacher demonstrations and simple student experiments are important in that they give students an understanding of the chemical concepts and motivate them to learn the subject. The recording of such additional experiments is at the teacher's discretion.
5.3 Student's Practical Work
The student experiments are important in that they develop practical skills, for example setting up and manipulating apparatus and making measurements and observations. The required experiments are listed at the end of the appropriate section of the syllabus. The experiments must be recorded by the students.
5.4 Errors and their treatment in Student's Practical Work
The students are required to have an appreciation of the errors inherent in practical work and the precautions that should be taken to reduce such errors. No quantitative treatment of errors is required. Students should appreciate that a measurement has a certain level of error, and they should be aware of sources of error in all the mandatory quantitative experiments.
5.5 Laboratory Organisation and Maintainence
The syllabus requires that students have access to a laboratory. This should make it possible for the experiments required by the syllabus and any other practical work to be carried out in a safe manner.
A catalogue of the available equipment and chemicals is an important part of the chemistry laboratory. Much of the equipment can be used in a number of ways, although there are items of equipment that illustrate specific syllabus concepts. Necessary precautions should be taken in storing these chemicals. These are outlined in the Department of Education and Science's publication Safetyin School Science.
When chemicals are being purchased, suppliers are obliged, on request, to supply material safety data sheets (MSDS). There are various web sites that contain a variety of these sheets in English. One such web site is referred to in section 2.5.
5.6 Chemicals and Equipment
Nearly all the chemicals and equipment listed in appendixes 2 and 3 are at present being used in schools that offer Leaving Certificate Chemistry. Many are also used for Junior Certificate Science practical work, or for practical work in Leaving Certificate Physics or Biology. Appendix 2 lists the chemicals needed for the mandatory experiments, the teacher demonstrations specified in the syllabus, and other experimental work to illustrate parts of the syllabus. A number of the chemicals used for the latter purpose are specifically mentioned in the syllabus. Appendix 3 lists the equipment required for mandatory experiments, specified demonstrations, and other experimental work.
5.7 Safety
The general principles of safe laboratory working procedures apply to Leaving Certificate Chemistry. The school safety statement should outline the hazards involved. A basic set of safety rules should be drawn up within the school and displayed in each laboratory and a copy given to each student every year. Appropriate protective clothing and equipment should be available and should be used as necessary. Procedures for the disposal of broken glassware, waste chemicals and solvents should be adequate and safe. For safety reasons, it is strongly recommended that chemicals with short shelf-life be purchased in the smallest amounts possible.
The resources and fittings in a chemistry laboratory should be such as to take into account hazards associated with gas, electricity and water, as well as those associated with the storage, handling, use and disposal of chemicals. Isolation switches for electric power and isolation valves for gas should be provided. A first aid kit, an eye wash kit and washing facilities (i.e., hot water, soap and towels) should be provided. Students should be aware of the correct procedures in the event of a fire or any other hazard. Appropriately located fire extinguishers, fire blankets, sand buckets and absorbent material for dealing with spills should also be provided.
Certain experiments and demonstrations require greater care, for example mandatory experiment no. 7.5 (the preparation and properties of ethanoic acid) and the demonstration of the reaction of potassium with water. The detailed safety precautions required for particular experiments and teacher demonstrations is beyond the scope of this document, but teachers should ensure that they have a clear understanding of the safety issues concerned. A list of useful references is included below.
5.8 References
CLEAPSS School Science Service
Hazcards (available from CLEAPSS School Science Service, Brunel University, Uxbridge UB8 3PH, England)
CLEAPSS School Science Service
Laboratory Handbook