Slovakia Maturita Chemistry flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Atomic number

The number of protons in the nucleus of an atom, which uniquely identifies the element and determines its position in the periodic table.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons, thus different mass numbers.

Ionic bond

A chemical bond formed by the electrostatic attraction between oppositely charged ions, typically between a metal and a nonmetal after electron transfer.

Mole

The amount of substance containing as many elementary entities as there are atoms in 12 g of carbon-12, equal to Avogadro's number (6.022×10^23).

Molar volume

The volume occupied by one mole of any gas at standard temperature and pressure (0 °C, 101.325 kPa), approximately 22.4 dm^3.

Limiting reactant

The reactant that is completely consumed first in a chemical reaction and thus determines the maximum amount of product that can be formed.

Alkali metals

The highly reactive elements of Group 1 of the periodic table (lithium, sodium, potassium, etc.) that react vigorously with water to form hydroxides and hydrogen.

Amphoteric oxide

An oxide that can react with both acids and bases to form salts, such as aluminium oxide (Al2O3) or zinc oxide (ZnO).

Displacement reaction

A redox reaction in which a more reactive element displaces a less reactive element from its compound, for example zinc displacing copper from copper sulfate solution.

Alkane

A saturated hydrocarbon with only single carbon-carbon bonds, general formula CnH2n+2, that undergoes substitution reactions.

Esterification

The acid-catalysed reaction between a carboxylic acid and an alcohol to produce an ester and water, often with a characteristic fruity odour.

IUPAC nomenclature

The systematic set of rules for naming organic compounds based on the longest carbon chain, lowest locants for substituents, and suffixes for functional groups.

Enzyme

A biological catalyst, usually a protein, that speeds up biochemical reactions by lowering activation energy and is sensitive to temperature and pH.

Peptide bond

The covalent amide linkage formed between the carboxyl group of one amino acid and the amino group of another, releasing water and forming proteins.

Reducing sugar

A sugar that can donate electrons to reduce mild oxidising agents such as Tollens' or Fehling's reagent, due to a free aldehyde or ketone group.

Enthalpy change

The heat energy exchanged with the surroundings at constant pressure during a chemical reaction; negative for exothermic and positive for endothermic reactions.

Le Chatelier's principle

When a system at equilibrium is disturbed by a change in concentration, pressure, or temperature, it shifts to counteract the change and restore equilibrium.

Electrochemical cell

A device that converts chemical energy into electrical energy (galvanic cell) or vice versa (electrolytic cell), involving oxidation at the anode and reduction at the cathode.

pH

A logarithmic measure of hydrogen ion concentration: pH = -log[H3O+]; values below 7 indicate acidity, 7 is neutral, and above 7 is basic at 25 °C.

Buffer solution

A solution that resists changes in pH when small amounts of acid or base are added, typically made from a weak acid and its conjugate base.

Titration

A quantitative analytical procedure in which a solution of known concentration is added from a burette to a measured volume of analyte until the equivalence point is reached.

Distillation

A separation technique that boils a liquid mixture and condenses the vapour to purify liquids or separate components based on differences in boiling point.

Filtration

A laboratory technique that separates an insoluble solid from a liquid by passing the mixture through a porous filter medium that traps the solid particles.

Chromatography

A separation method in which components of a mixture distribute differently between a stationary phase and a mobile phase, allowing identification and purification.

Greenhouse effect

The warming of Earth's surface caused by atmospheric gases such as CO2, CH4, and water vapour absorbing and re-emitting infrared radiation from the surface.

Haber process

The industrial synthesis of ammonia from nitrogen and hydrogen gases using an iron catalyst at high pressure and moderate temperature, essential for fertiliser production.

Hard water

Water containing dissolved calcium and magnesium ions that reduces soap lathering and forms scale; it can be softened by ion exchange or precipitation.

Covalent bond

A chemical bond formed by the sharing of one or more pairs of electrons between atoms, typically between nonmetals, resulting in discrete molecules or network solids.

Empirical formula

The simplest whole-number ratio of atoms of each element in a compound, derived from percent composition or experimental mass data.

Ester

An organic compound formed by replacing the hydrogen of a carboxylic acid with an alkyl or aryl group, often having a pleasant fruity smell and used as flavourings or solvents.

ATP

Adenosine triphosphate, the universal energy currency of cells, releasing energy when its terminal phosphate bond is hydrolysed to ADP and inorganic phosphate.

Electrolysis

The use of an external electrical current to drive a non-spontaneous chemical reaction, such as decomposing molten sodium chloride into sodium and chlorine.