what chemistry deals with and you know the basics of this subject;
what is the basic laboratory equipment and its purpose;
what are the warning pictograms on containers with chemical reagents and what health and safety rules are applied when working with substances and preparations.
to safely conduct experiments in a chemical laboratory;
to recognize interesting substances used in everyday life;
to determine the positive and negative effects of various substances on human health and the environment;
to assess the role of chemistry in the modern world.
Mineral raw materials
Can mineral raw materialsmineral raw materials that we source from the Earth surprise us with something? The world as we know it would not exist without concrete, steel, aluminium, glass or plastics. You may have already heard about carbon, appearing in the form of a diamond or graphene, and if you do not, you will certainly learn about this element in a chemistry lesson. Many discoveries, without which we cannot imagine modern civilization, we owe to chemists. Have you ever heard about the method of breeding crystals of Jan Czochralski? Its discovery, as it often happens, happens by chance. Professor Czochralski mistakenly immersed the nib of his fountain pen in a crucible with molten tin and it turned out that a thin thread of crystallized metal hanging at the end of the nib was entirely a single crystal (single crystal). His idea, developed in 1916, is the oldest and until now the only known way to receive this type of material.
What do you think will happen if you will put some salt (sodium chloride) into the copper(II) sulphate solution in which the aluminium foil is immersed? Before watching the movie „Testing the influence of sodium chloride on the reaction of copper(II) sulphate with aluminium”, write down the research question and hypothesis. Write down your observations and conclusions after getting acquainted with the film material.
Testing the influence of sodium chloride on the reaction of copper(II) sulphate with aluminium.
Aluminium is a metal more active than copper, so it should displace copper from the solution .
copper(II) sulphate solution,
aluminium foil,
sodium chloride,
beaker,
measuring cylinder,
teaspoon.
Pour approx. 20 cmIndeks górny 33 of copper(II) sulphate solution and insert a piece of aluminium foil so that it protrudes above the vessel. Watch for changes.
Then add a pinch of sodium chloride to the solution. Are any changes visible now?
Chemistry of cleaning products
In the ancient times perfumes had a high price and made a great career. In the contemporary world, we meet countless fragrances. It is believed that the fragrances can have a strong impact on us, setting the right mood. Probably the aroma of coffee stimulates and removes fatigue, the smell of lemon and violet helps to concentrate, and the wood violet itself has a positive effect on the speed of learning. Aromatherapy is used in medicine, recently for example to support the processes of waking people from coma. Fragrances facilitate communication in the animal world. An example is bombykol – the first of the chemically described pheromones, secreted by female mulberry silkworm that attracts males from a distance of about 10 kilometres.
Calculate how many particles of bombykol were in 6.4 mg of the test tube that Butenandt received, since the trillion molecules of this compound have a mass of approx. g? Is the smell a physical property or rather a chemical property of the substance?
Chemistry and health. Chemistry in the kitchen
Contemporary pharmacy and modern cuisine are two areas that combines care of the health. Hippocrates, considered the father of medicine, said: Your food should be a medicine, and your medicine should be food. These words make us realize how important the influence of nutrition has on the quality of our lives. This applies not only to people struggling with obesity and such diseases such as phenylketonuria or diabetes, but also those who do not notice this dependence on a daily basis.
Before you conduct the „Detection of glucose in the solution” experiment, make a note of the research question and hypothesis. Write down your observations and conclusions after the research.
Detecting the presence of glucose in the solution.
Glucose gives a positive result in Tollens’ reagent.
glucose solution,
Tollens’ reagent, i.e. ammonia solution of silver oxide,
a brand new test tube (or carefully degreased),
water bath,
tripod,
ceramic mesh,
thermometer,
burner.
For a brand new or well‑degreased test tube, put approx. 2 cmIndeks górny 33 of glucose solution and add some Tollens’ reagent.
Place the tube in a water bath and heat for approx. 80 minutes at a temperature of approx. 80°C.
Chemistry of the soil
Chemicals play a huge role in agriculture. Pesticides help to destroy pests, weeds, insects, fungi, can act as a repellent or luring agent for animals, facilitate the removal of leaves, and help to dry them before harvesting and reducing excessive number of flowers in horticulture. In addition, the use of fertilizers supplies the soil with various macro- and microelements. Of course, all of these measures should be used by farmers in accordance with the given rules of dosing, preparation of solutions of a certain concentration and their mutual mixing.
Calculate how many grams of ammonium nitrate () should be weighed to get the same amount of nitrogen as found in 40 g of urea, a compound of the formula: ?
Fuels – now and in the future
By reading this e‑textbook, you will learn how chemists have contributed to the development of energy and transport over the years, obtaining increasingly efficient fuels, improving energy sources and materials used to build cars, planes or space ships. What will humanity do when fossil fuels run out? Will the solution be the use of gas from shale deposits or will the energy industry go in a completely different direction?
Before you watch the demonstration of the experiment „Testing the perhydrol reaction with potassium permanganate”, write down the research question and hypothesis. Write down your observations and conclusions as well.
Checking whether the reaction of perhydrol with potassium permanganate is an exergonic process.
A large amount of energy is released in the reaction of perhydrol with potassium permanganate.
conical flask (Erlenmeyer flask) or beaker,
measuring cylinder,
spoon,
perhydrol,
crystals of potassium permanganate.
Pour approx. 40 cmIndeks górny 33 of perhydrol into a conical flask (30% solution ) and carefully put some crystals of potassium permanganate ().
After the experiment, carefully check the temperature of the flask with your hand.
Hydrogen peroxide, which is a component of perhydrol, reduces the potassium manganate to manganese dioxide, according to the reaction equation:
The resulting manganese dioxide is a catalyst for the decomposition reaction :
This reaction is strongly exergonic, which causes a rapid boiling of the solution and evaporation of the water formed.
Chemistry of packaging and clothing
In many places our planet looks like a big landfill. We buy more and more often the goods that we use only for a short time. For example, food items in disposable packaging, as well as the content of our clothing closet, when trying to keep up with the ever‑changing fashion. We choose plastic products more often, which due to high competition on the market are more and more attractive to us, although they adversely affect the natural environment. Who wonders how much day‑to‑day waste is thrown away? What to do with this mountain of rubbish? These lie not only near large urban agglomerations – these often end up in seas and oceans. We have accumulated quite a lot in space as well.
Summary
Chemistry is a science that focuses on the composition and structure of substances, their transformations and the conditions in which these occur.
Chemistry is used in almost all aspects in life.
Justify the statement that baking soda is a compound with a wide range of applications.
Keywords
Chemistry, science, sections of chemistry
Glossary
feromony – związki chemiczne wydzielane i wyczuwane przez zwierzęta i rośliny w celu przekazywania informacji (komunikacji)
insulina – hormon peptydowy mający podstawowe znaczenie w przemianie cukrów, białek i tłuszczów
monokryształ – ciało krystaliczne odznaczające się jednakową orientacją sieci krystalicznej, niezależnie od wielkości kryształu
pasywacja – proces przeprowadzania substancji w stan pasywny; proces pasywacji dotyczy głównie metali, pokrywających się szczelną powłoką, która chroni je przed dalszymi reakcjami w danym środowisku oraz izoluje metal od substancji, które go otaczają
perhydrol – ok. 30‑procentowy wodny roztwór nadtlenku wodoru ()
surowce mineralne – skały i minerały wykorzystywane przez człowieka w różnych dziedzinach życia