Chemistry lab pt 2
what the scientific discipline called chemistry is about;
who a chemist is and how to become a chemist;
industries chemistry is associated with;
what the pictograms on the labels of products used in your environment mean.
the importance of laboratories in different scientific and industrial fields;
to apply the safety rules in practice in the chemical laboratory;
what is the purpose of observing the regulations of the school laboratory and how to apply them to chemical experiments and tests;
identify laboratory equipment and glassware and discuss their use;
recognize markings of hazardous, corrosive, explosive, flammable or environmentally hazardous substances that can be found in the laboratory.
Principles of work in the laboratory
Think about how to behave in a laboratory, and then draw up regulations for the chemical laboratory. You can write it in here. What is the basis for such a course of conduct?
Check if the code of conduct in the chemical laboratory that you elaborated match those that are in line with the health and safety rules adopted in each school.
Expand subsequent points and read the regulations of the chemical laboratory.
When can I enter the laboratory?
You can enter the laboratory after being told to do so and in the presence of the teacher.
Can I bring my own chemical materials?
You cannot bring any materials to the chemical laboratory without the teacher's permission.
How do I perform experiments?
You perform the experiment following strictly the descriptions in the textbooks or those given by the teacher.
What should I do before starting an experiment?
Before starting an experiment you should put goggles, protective apron on and use other personal protective equipment (protective gloves).
Why some substances are marked with warning pictograms?
They are hazardous, which means that they may cause skin irritation for example. Special precautions must be taken when working with substances marked with warning pictograms.
What should I keep in mind when working?
You should keep order during and after the experiments.
How should I work with the substances used for an experiment?
All substances used for an experiment must be treated as potentially hazardous, i.e. we do not touch them, do not check their taste or smell (in exceptional cases you will test these properties explicitly on the teacher's instructions and under his/her supervision).
How do I check the smell of substances?
You should smell the substances carefully, with the lungs filled with air, gently ventilating their vapors with a movement of the hand towards the nose.
What should I keep in mind when heating substances in test tubes?
When heating substances in test tube you should be careful to point its mouth in the direction where there are no persons.
Can I take something from the laboratory after a lesson?
You cannot take anything from the chemical laboratory without the teacher's permission.
What should I do after finishing my work?
After finishing experiments you should wash your hands thoroughly.
Do I have to inform teacher if I spill something for example?
All the accidents, like injuries, burns or spills are to be reported to the teacher.
How to properly perform basic laboratory activities?
Laboratory techniques are activities the mastery of which is a prerequisite for proper experimental work; the order in which they are performed is not arbitrary and knowledge of the activities is a necessary element for obtaining correct results and ensuring safety in the laboratory.
By conducting experiments in the chemical laboratory, we engage our senses, receiving specific stimuli that provide us with information about the phenomena we are studying. We must be particularly careful to ensure that the sensory organs are properly protected. The risk of dangerous substances being absorbed into the body through the skin, mucous membranes and respiratory tract must always be borne in mind.
Odors and sense of smell
What is commonly referred to as smell is in fact an odor impression, i.e. the ability of a substance to stimulate the olfactory organ. Depending on the experience and individual properties of a person, the description of a smell can be a single word or take the form of a specialist study (e.g. for the perfumery industry).
The proper olfactory organ is the olfactory epithelium located at the top part of the nasal cavity, constituting approximately 2 cmIndeks górny 22 area in each nasal opening. The olfactory cells come into contact with the air through a system of dendrites with cilia in which receptors are located, while the other end of the cell has access to the brain through its elongated part (3‑4 cm long axon). Interestingly, the sense of smell fades with age, but the cells themselves are renewed throughout the body's life.
How can the smell of unknown products, e.g. food and cosmetics, be tested safely?
Testing of smell must be carried out with special care. We test smell by bringing the tested substance directly to the nose.
test tube stand,
test tubes,
water,
cake flavoring,
vinegar,
nail polish remover.
Pour small amounts of water, cake flavoring, nail polish remover, vinegar to the test tubes.
Bring the tubes with the tested substances at the distance of about 20 cm from your nose, and next direct the vapors by hand towards the nose.
How do we handle liquid substances in the laboratory?
Which of the safety rules for chemical laboratory is incorrect? Select the correct answer.
- You can taste the substances used in the experiments.
- You should smell the substances carefully.
- When working with substances marked with warning pictograms, you should take all precautions.
- After finishing experiments you should wash your hands.
Complete the text.
Substances marked with the pictogram .................. must not be put on the table near the ignited burner. After finishing an experiment, substances marked with the pictogram .................. must not be pured to the common sink. Substances marked with the pictogram .................................................. must not be used to water plants. Substance marked with the pictogram .................. can also be marked as ................... During chemistry lessons, the teacher is obliged to discuss given substances which are used during given lesson according to .....................................
Conclusion
In the chemical laboratory the rules of health and safety must be followed.
Use special glassware, dishes and laboratory equipment to perform chemical experiments.
When planning an experiment, it is important to remember to use reagents rationally in order to reduce the amount of waste generated.
Chemical experiments should be performed on the laboratory table in accordance with laboratory work techniques, bearing in mind the principles of health and safety and order.
Keywords
health and safety rules, laboratory, safety, laboratory techniques, pictograms, hazardous substances, safety data sheet
Glossary
karta charakterystyki substancji – dokument zawierający opis zagrożeń, jakie dana substancja może spowodować podczas jej użytkowania
techniki laboratoryjne – czynności, których opanowanie jest podstawowym warunkiem właściwej pracy eksperymentalnej: ważna jest ich kolejność i dokładność w wykonywaniu
laboratorium – pomieszczenie, w którym wykonuje się eksperymenty badawcze
nabłonek węchowy – część błony śluzowej jamy nosowej, w której znajdują się zakończenia włókien nerwu odbierającego bodźce węchowe