Chemistry Admission Test Practice - Medical University of Plovdiv

A comprehensive set of vocabulary flashcards covering general, inorganic, and organic chemistry concepts based on the Medical University of Plovdiv admission test practice material.

Covalent chemical bond formation

A process occurring when atoms have valence electrons with antiparallel spins, resulting in a decrease of potential energy compared to isolated atoms.

Hydrogen fluoride molecule (HF)

A molecule characterized by a covalent bond where the shared electron pair is drawn to the more electronegative fluorine atom.

Shared electron pair

Formed as a result of partial overlap of atomic orbitals and redistribution of electron density between two atoms.

Relationship between bond energy and length

Generally, the shorter the chemical bond connection, the stronger the bond energy.

Zero dipole moment

Characteristic of symmetrical molecules such as $CH_4$, $CCl_4$, and $SO_3$.

$\sigma$-bonds

Simple chemical bonds that are formed using hybrid orbitals.

Lewis theory dots

Representation of valence electrons in the Lewis theory of the covalent chemical bond.

Carbon dioxide ($CO_2$) bonds

The molecule contains two $\sigma$-bonds and two $\pi$-bonds.

Donor-acceptor bond

The type of chemical bond formed in the complex ion during the reaction: $Cu(OH)_2 + 4NH_3 \rightarrow [Cu(NH_3)_4]^{2+} + 2OH^-$.

Ionic chemical bond

A bond formed between atoms of chemical elements with a very large difference in their electronegativity.

Metallic crystal lattice

Characteristic of substances that are thermally and electrically conductive due to free-moving electrons.

Van der Waals interactions

Forces of attraction that exist between nonpolar molecules.

Triple bond composition

Consists of one $\sigma$-bond and two $\pi$-bonds.

Activation energy

The energy required to break the existing bonds in molecules; reactions with low activation energy occur at high rates at $25\,^{\circ}C$.

Saturated solution

A solution where an equilibrium has been established between the solid solute and the aqueous phase (e.g., $NaCl(solid) \rightleftharpoons NaCl(aq)$).

Sublimation

The phase change from a solid directly to a gas.

Neutralization product

A substance like $KNO_3$ formed from the reaction of a strong acid ($HNO_3$) with a strong base ($KOH$).

Rate Law

Expressed for the reaction $A(solid) + 2B(aq) \rightarrow D(solid)$ as $V = k \times [B]^2$.

Henry's law

Relates to the solubility of gases in liquids but does not apply to gases that react with the solvent, such as $NH_3$.

Chemical kinetics

A branch of chemistry that studies the rate and mechanism of chemical reactions.

Rate constant factors

Depends on the temperature, the presence of a catalyst, and the nature of the reactants, but not on their concentration.

Autocatalytic process

A process in which the catalyst is one of the reaction products.

Isothermal equilibrium rates

At chemical equilibrium, the rates of the forward and reverse reactions are equal.

Isotonic solutions

Solutions that possess the same osmotic pressure.

Brønsted-Lowry acid

A substance that acts as a proton donor in aqueous solution.

Hydrolysis

The reverse of a neutralization reaction.

Beckmann’s law

States that the elevation of the boiling point of a solution compared to the pure solvent is directly proportional to its molar concentration.

Dispersed phase

The substance in a dispersed system whose particles are distributed throughout a dispersed medium.

Strong electrolytes

Substances like $HBr$, $HI$, and $HClO_4$ that completely dissociate into ions in aqueous solutions.

Ion product of water ($K_w$)

A constant that remains unchanged when a strong acid is added to pure water at a constant temperature.

Arrhenius base

A substance that releases $OH^-$ ions in aqueous solution.

Conjugate acid-base pair

Two substances that differ from each other by the presence or absence of a single proton ($H^+$).

Oxidizing agents

Atoms or ions that accept electrons in a redox process, thereby lowering their oxidation state.

Reducing agents

Atoms or ions that donate electrons in a redox process, thereby raising their oxidation state.

Amphoteric hydroxides

Hydroxides like $Pb(OH)_2$, $Zn(OH)_2$, $Al(OH)_3$, and $Cr(OH)_3$ that can react with both acids and bases.

Isomers

Compounds with the same qualitative and quantitative composition but different structures and properties.

Homologous series

A series of organic compounds with the same qualitative composition and similar properties, differing by one or more $CH_2$-groups.

Chiral carbon

A carbon atom bonded to four different substituents.

Polyvinyl chloride (PVC)

A polymer produced by the addition polymerization of chloroethene.

Tollens's reagent

Used to identify glucose by the presence of an aldehyde group, resulting in a 'silver mirror'.

Saponification

The alkaline hydrolysis of fats and oils to produce glycerol and soap.

Peptide bond

The specific bond formed between $\alpha$-amino acids in proteins.

Biuret test

A qualitative test used to prove the presence of peptide bonds in a protein molecule.

Ninhydrin test

A test where an alcoholic solution reacts with $\alpha$-amino acids to form a violet solution.