Bulgaria DZI Chemistry study guide
Bulgaria DZI Chemistry · Work through your exam, one topic at a time.
The Bulgarian State Matriculation Exam in Chemistry (ДЗИ по химия) is the school-leaving examination taken by students at the end of upper secondary education in Bulgaria. A result in chemistry is used for admission to university programmes in chemistry, pharmacy, medicine, biology, food technology and related fields, and it also serves as a formal record of achievement for candidates who simply want the subject on their diploma. The Bulgaria DZI Chemistry study guide has 9 sections and about 2,637 words.
01Atomic Structure and the Periodic Law
Every candidate must move fluently between the nuclear model (protons, neutrons, isotopes), the electron-configuration model (shells, subshells, orbitals, the aufbau order, Hund's rule, Pauli exclusion), and the periodic table as a map of those configurations. Know that group number follows valence-shell count for main-group elements, that period number equals the highest occupied shell, and that periodic trends (atomic radius, ionisation energy, electron affinity, electronegativity, metallic character) all follow from effective nuclear charge and shielding.
362 words, about 2 min02Chemical Bonding and the Structure of Matter
Candidates must distinguish ionic, covalent (polar and nonpolar), metallic and intermolecular bonding, and connect each to physical properties. For covalent substances, use the octet rule, Lewis structures, VSEPR geometry, hybridisation and polarity of the whole molecule (not just the bonds).
332 words, about 2 min03Chemical Reactions and Stoichiometry
Master equation balancing, the mole concept, molar mass, molar volume of a gas at standard conditions, and the stoichiometric ratio as a conversion factor. Know the main reaction types - combination, decomposition, single and double displacement, combustion, neutralisation, redox - and be able to assign oxidation states and identify the oxidising and reducing agents.
279 words, about 1 min04Solutions and Electrolytic Dissociation
Understand concentration (molarity, mass percent, molality), dilution, solubility rules, and the behaviour of strong and weak electrolytes. Strong electrolytes dissociate completely (strong acids, strong bases, soluble salts); weak electrolytes do so partially (weak acids, weak bases, water).
296 words, about 1 min05Inorganic Chemistry: Nonmetals and Their Compounds
Know the chemistry of hydrogen, halogens, oxygen and sulfur, nitrogen and phosphorus, carbon and silicon, plus their key compounds. Focus on preparation, characteristic reactions, and industrial or laboratory importance: chlorine with alkali, hydrogen halides and their acid strength, sulfuric acid manufacture and properties, nitric acid as an oxidiser, ammonia synthesis and its basicity, and the allotropes of carbon and phosphorus.
315 words, about 2 min06Inorganic Chemistry: Metals and Their Compounds
Learn the reactivity series, the extraction of metals (electrolysis for reactive metals, reduction with carbon or carbon monoxide for less reactive ones), and the properties of key metal compounds. Focus on alkali and alkaline-earth metals (water reactions, oxide basicity, hydroxide solubility), aluminium (amphoteric oxide and hydroxide), iron (oxidation states +2 and +3, rusting), and copper (less reactive, used for electrical work).
279 words, about 1 min07Organic Chemistry: Hydrocarbons
Understand homologous series, functional-group families and isomerism. For hydrocarbons, know alkanes (saturated, substitution reactions, combustion), alkenes and alkynes (unsaturation, addition reactions, Markovnikov-type orientation), and aromatic hydrocarbons such as benzene (delocalised ring, substitution rather than addition).
233 words, about 1 min08Organic Chemistry: Oxygen- and Nitrogen-Containing Compounds
Know alcohols, phenols, ethers, aldehydes, ketones, carboxylic acids, esters, and nitrogen compounds such as amines and amides. Focus on functional-group reactions: oxidation of primary alcohols to aldehydes and then acids, secondary alcohols to ketones, esterification, hydrolysis of esters, and the basicity of amines.
263 words, about 1 min09Chemical Energetics, Kinetics and Equilibrium
Separate three ideas: energetics (enthalpy change, exothermic vs endothermic, bond breaking and forming, Hess's law), kinetics (rate, collision theory, activation energy, catalysts, factors affecting rate), and equilibrium (dynamic equilibrium, Le Chatelier's principle, equilibrium constant expression). Know that catalysts speed up both forward and reverse reactions equally and do not change the equilibrium position or the enthalpy change.
278 words, about 1 min