Chemical Bonding and Reactions: A Comprehensive Guide
Chemical Bond: mutual electrical attraction between the nuclei and valence electrons of different atoms that binds the atoms together.
Ionic Bonding: Chemical bonding that results from the electrical attraction between cations and anions.
Covalent Bonding: Results from the sharing of electron pairs between two atoms.
Electronegativity: a measure of an atom’s ability to attract electrons.
- Nonpolar covalent bond: a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge.
- Polar covalent bond: covalent bond in which the bonded atoms have an unequal attraction for the shared electrons.
- Polar: uneven distribution of charge.
Molecule: a neutral group of atoms that are held together by covalent bonds.
Molecular compound: chemical compound whose simplest units are molecules.
Chemical formula: indicates the relative numbers of atoms of each kind in a chemical compound by using atomic symbols and numerical subscripts.
Molecular formula: indicates the types and numbers of atoms combined in a single molecule of a molecular compound.
Diatomic molecule: a molecule containing only 2 atoms.
Bond energy: energy required to break a COVALENT bond and form neutral isolated atoms.
Resonance: the bonding in molecules or ions that cannot be correctly represented by a single Lewis structure.
Ionic compound: positive and negative ions (cations and anions) that are combined so that the numbers of positive and negative charges are equal.
Formula unit: simplest collection of atoms from which an IONIC COMPOUND formula can be established.
Lattice energy: energy released when one mole of an ionic crystalline compound is formed from gaseous ions.
Polyatomic ions: a charged group of covalent bonded atoms.
Metallic bonding: chemical bonding resulting from the attraction between metal atoms and the surrounding sea of electrons.
- Malleability: the ability of a substance to be hammered or beaten into thin sheets.
- Ductility: the ability of a substance to be drawn, pulled, or extruded through a small opening to produce a wire.
VSEPR Theory: Valence-Shell Electron Pair Repulsion Theory.
VSEPR Theory: repulsion between the sets of valence-level electrons surrounding an atom causes the sets to be oriented as far apart as possible.
Dipole-dipole forces: forces of attraction between polar molecules.
Dipole: created by equal but opposite charges that are separated by a short distance.
London dispersion forces:
- the intermolecular attractions resulting from the constant motion of electrons and the creation of instantaneous dipoles.
- forces act between all atoms AND molecules.
- forces are NOT present in intramolecular forces.
- increases with atomic mass or molar mass.
Hybridization: the mixing of two or more atomic orbitals of similar energies on the same atom to produce new orbitals of equal energies.
Hybrid orbitals: orbitals of equal energy produced by the combination of two or more orbitals on the same atom.
Monatomic ions: ions formed from a single atom.
Binary compounds: compounds composed of two elements.
Oxyanions: polyatomic ions that contain oxygen.
Binary acids: acids that consist of two elements, usually hydrogen and one of the halogens—fluorine, chlorine, bromine, iodine.
Oxyacids: acids that contain hydrogen, oxygen, and a third element (usually a nonmetal).
Salt: ionic compound composed of a cation and the anion from an acid.
Formula mass: sum of the average atomic masses of all atoms represented in its formula.
Empirical formula: a chemical formula that shows the composition of a compound in terms of the relative numbers and kinds of atoms in the simplest ratio.
Hydrocarbons: molecular compounds composed solely of carbon and hydrogen.
Stock System: used to distinguish the ions formed when elements form two or more cations with different charges; used a Roman numeral to indicate an ion’s charge.
Molar mass: the mass in grams of one molecule of a substance; a compound’s molar mass is numerically equal to its formula mass.
Precipitate: a solid that forms from a solution during a chemical reaction.
Reversible reaction: a chemical reaction in which the products re-form the original reactants.
Synthesis reaction: a reaction in which two or more substances combine to form a new compound.
Decomposition reaction: a reaction in which a single compound breaks down to form two or more simpler substances.
Electrolysis: the decomposition of a substance by an electric current.
Single-displacement reaction: a reaction in which atoms of one element take the place of atoms of another element in a compound.
Double-displacement reaction: When the positive ion of one compound replaces the positive ion of another to form two new compounds.
Combustion reaction: a chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light.
Activity series: a list of elements organized according to the ease with which the elements undergo certain chemical reactions.
Composition stoichiometry: deals with the mass relationships of elements in compounds.
Reaction stoichiometry: calculations involving the mass relationships between reactants and products in a chemical reaction.
Mole ratio: a conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction.
Limiting reactant: the substance that controls the quantity of product that can form in a chemical reaction.
Excess reactant: The substance that is not used up completely in a reaction.
Theoretical yield: the maximum amount of product that can be produced from a given amount of reactant.
Actual yield: the measured amount of a product obtained from a reaction.
Percentage yield: The ratio of the actual yield to the theoretical yield, multiplied by 100.
Diffusion: Spontaneous mixing of the particles of two substances caused by their random motion.
Effusion: A process by which gas particles pass through tiny openings.
Elastic Collision: Collisions between gas particles, other particles, and container walls-with no net loss of kinetic energy.
Fluids: Liquids or gases that flow.
Ideal Gas: An imaginary gas that perfectly fits all assumptions of the Kinetic Molecular Theory.
Real Gas: A gas that does not behave completely according to the assumptions of the Kinetic Molecular Theory.
Kinetic Molecular Theory: Based on the idea that particles of matter are always in motion.
Atmosphere Pressure: (Atm) Define as equivalent to 760mm Hg.
Barometer: A device used to measure atmospheric pressure.
Standard Temperature & Pressure: (STP) Standard condition of atm pressure and zero degrees Celsius.
Boyle’s Law: The volume of a fix mass of a gas at constant pressure varies inversely with pressure and temp.
Charles’ Law: The volume of a fixed mass of gas at a constant pressure varies directly with the Kelvin temp.
Dalton’s Law: Total pressure of the mixture of gases is equal to the sum of the particle pressures of the component gases.
Gas Laws: simple mathematical relationships between the volume, temp., pressure, and the amount of gas. Gay-Lussac’s Law: The fixed amount of gases’ pressure depends on the Kelvin scale.
Partial Pressure: The pressure of each gas in a mixture.
Newton: The force that will increase the speed of a one-kilogram mass by one meter per second each second that the force is applied.
Pascal: The pressure exerted by a force of one newton acting on an area of one square meter and is symbolized by Pa.
Partial pressure: The pressure of each gas in a mixture.
Dalton’s law of partial pressures: States that the total pressure of a gas mixture is the sum of the partial pressures of the component gases.
Boyle’s Law: States that the volume of a fixed mass of gas varies inversely with the pressure at constant temperature.
Charles’ Law: States that the volume of a fixed mass of gas at a constant pressure varies directly with the Kelvin temperature.
Gay-Lussac’s Law: The pressure of a fixed mass of gas at a constant volume varies directly with the Kelvin temperature.
Combined gas law: Expresses the relationship between pressure, volume, and temperature of a fixed amount of gas.
Gay-Lussac’s law of combining volumes of gases: States that at constant temperature and pressure, the volumes of gaseous reactants and products can be expressed as ratios of small whole numbers.
Avogadro’s law: States that equal volumes of gases at the same temperature and pressure contain equal numbers of molecules.
Ideal gas law: The mathematical relationship among pressure, volume, temperature, and the number of moles of a gas.
Graham’s law of effusion: States that the rates of effusion of gases at the same temperature and pressure are inversely proportional to the square roots of their molar masses.
Solution: a homogeneous mixture of two or more substances in a single phase.
- Homogeneous: same throughout.
- Heterogeneous: different throughout.
Soluble: able to be dissolved.
Insoluble: not able to be dissolved.
Solvent: the component of the mixture that does the dissolving.
Solute: the substance that is dissolved.
Suspensions: heterogeneous mixture in which the particles will settle upon standing, can be separated on filtration, and will show the tyndall effect (orange juice with pulp).
Colloid: heterogeneous mixture with particles smaller than a suspension and larger than a solution. Do not separate upon standing, do not separate by filtration, but can show the tyndall effect.
Electrolyte: substance that dissolves in water to produce ions therefore the solution can conduct electricity.
Nonelectrolytes: substances that dissolve in water but does not break into ions and cannot conduct electricity.
Molarity: moles of solute/liters of solution; M.
Factors affecting the rate of dissolution: increasing the surface area of the solute, agitation, heating.
Solution equilibrium: the physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates.
- Saturated: contains the maximum amount of dissolved solute.
- Unsaturated: contains less then the maximum amount of solute.
- Supersaturated: contains more solute than a saturated solution under the same conditions.
Solubility values: states the amount of specific substance required to form a saturated solution with a specific amount of solvent at a specified temperature.
Immiscible: when two liquids will not dissolve in each other (water and oil).
Miscible: liquids that dissolve freely in one another in any proportion (ethanol and water).
William Henry’s Law: the solubility of a gas in a liquid in directly proportional to the partial pressure of that gas on the surface of the liquid.
Effervescence: the rapid escape of gas in a liquid in which it is dissolved.
Solvated: a solute particle that is surrounded by solvent molecules.
Enthalpy of solution: the amount of heat energy absorbed or released when a specific amount of a solute dissolved in a solvent.
Concentrated: contains large amount of solute.