Chemistry is powerful

Panayot Volov Primary School� Varna, Bulgaria

Project

International Year of Chemistry

Chemistry is a powerful and serious science.� It does not, however, prevent us from making fun, entertaining us.

Human progress has continued for many millennia. Thousands of years have passed since our distant ancestors escaped from the caves. For thousands of years, man has struggled with the raw Nature,

Welcome friends of the good mage - Chemistry!

Welcome,friends of the eternal companion of man, the science of miracles - Chemistry!

step by step penetrated into her secrets, slowly but surely mastered her elements to become a slave to nature in her lord. Tough was the way to progress, but the human thirst for knowledge has pushed people invariably.

One of the sciences, whose roots we find in the hearth of the ancient man, is chemistry. The chemical knowledge has illuminated people's way to the luminous peaks of civilization that man has reached today.�

If you know chemical laws, you become the leader of chemical reactions. They become the obedient executors of your commandments.

Chemical reactions with acids, with bases and with salts

NaOH

It is a colorless crystalline substance.

Allowed in air, it sucks moisture.

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NaOH

• The aqueous sodium hydroxide solution has a basic character. This is due to free hydroxide ions.

The interaction between acid and base to produce salt and water is called� neutralization.

The aqueous solution of NaOH stains phenolphthalein in raspberry red, and the red litmus and the universal indicator in blue.

Properties of acids �Киселините са съединения, чийто водни разтвори съдържат само водородни положителни и киселинни отрицателни йони и променят цвета на синия лакмус и на универсалния индикатор в червено

Hydrochloric acid

• Hydrochloric acid (HCl) is not a single compound.

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• It is an aqueous solution of hydrogen chloride.

Променят цвета на универсалния индикатор в червено, което показва, че във водните им разтвори се съдържат водородни йони

Reaction of HCl with Zn and Mg

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2HCI + Mg→MgCI₂ +H₂

2HCI + Zn→ZnCI₂ +H₂

The results of the experiments show that the acids interact with active metals, with basic oxides and with bases.

The reagent for detection of HCl and its salts is AgNO₃. A white precipitate of AgCl is obtained.

Chemical reactions with acids, with bases and with salts