General Chemistry: Bonding, Chemical Reactions, Stoichiometry, and Thermochemistry

Practice vocabulary flashcards covering key definitions across General Chemistry Chapters 3, 4, 5, and 6: Ions and Bonding, Chemical Equations and Reactions, Stoichiometry, and Thermochemistry.

Cation

A positively charged ion that forms when a neutral atom loses one or more electrons.

Anion

A negatively charged ion that forms when a neutral atom gains one or more electrons.

Isoelectronic

A term describing atoms or ions that possess the exact same number of electrons.

Coulomb's Law

The law stating that the electrostatic force of attraction between two charged particles is given by $F_e = k_e \frac{|q_1 q_2|}{r^2}$, which is strongest when the charges are large and the distance between them is small.

Crystal Lattice

A three-dimensional framework in which alternating positive and negative ions pack closely together, extending in all directions.

Empirical Formula

A chemical formula that gives the smallest whole-number ratio of ions or atoms present in a compound.

Formula Unit

The smallest collection of ions electrically balanced to form a neutral ionic compound (such as $\text{NaCl}$ for sodium chloride).

Hydrate

An ionic compound that contains water molecules trapped within its crystal lattice in a specific ratio.

Covalent Bond

A chemical bond formed when two nonmetallic atoms share pairs of electrons.

Molecular Formula

A chemical formula that represents the actual number of each type of atom in a molecule of a covalent compound.

Ionization

The process occurring when a soluble ionic compound dissolves in water, causing its constituent ions to dissociate from one another and become solvated by water molecules.

Electrolyte Solution

An electrically conducting aqueous solution composed of dissolved, separated cations and anions that carry an electric current.

Oxoanion

A polyatomic anion that contains one or more oxygen atoms bonded to a central element.

Mass Spectrometer

An analytical instrument that vaporizes and ionizes molecules, accelerates them through an electric field, and deflects them with a magnetic field proportional to their mass to determine molecular mass.

Combustion Analysis

A method of elemental analysis where a combustible sample is burned completely in excess oxygen to produce $\text{CO}_2$ and $\text{H}_2\text{O}$, which are captured to determine the masses of carbon and hydrogen.

Stoichiometric Coefficients

Numbers placed before chemical formulas in a balanced chemical equation to represent relative numbers of molecules, formula units, or moles, ensuring mass is conserved.

Synthesis Reaction

A chemical reaction in which two or more starting materials combine to form a single product.

Decomposition Reaction

A chemical reaction in which a single compound breaks down into two or more simpler substances.

Single Displacement Reaction

A reaction classification in which one element replaces another element in a compound.

Double Displacement Reaction

A chemical reaction classification in which two ionic compounds exchange ions to form two new compounds.

Precipitation Reaction

A double displacement reaction occurring between two soluble compounds that produces an insoluble solid compound called a precipitate.

Acid-Base Neutralization

A double displacement reaction between an acid and a base that produces water and a salt.

Mole

The standard SI unit for amount of substance, representing exactly $6.02 \times 10^{23}$ representative particles (Avogadro's number).

Molar Mass

The mass in grams of one mole ($6.02 \times 10^{23}$ particles or formula units) of a substance, expressed in $\text{g}\,\text{mol}^{-1}$.

Stoichiometry

The numerical study of the relationships between the amounts of reactants and products involved in a chemical change (derived from Greek stoicheion meaning element, and metron meaning measure).

Limiting Reagent

The reactant that is completely consumed first in a chemical reaction, thereby limiting the maximum amount of product that can form.

Excess Reagent

The reactant that remains unconsumed after the limiting reagent has been completely used up in a chemical reaction.

Molarity

A measure of concentration defined as the number of moles of solute dissolved per liter of solution ($\text{M} = \frac{\text{mol}}{\text{L}}$).

Gravimetric Analysis

An analytical technique used to determine the concentration of ions in an aqueous solution by precipitating the analyte and measuring the mass of the resulting precipitate.

Theoretical Yield

The calculated maximum quantity of product that can be formed from given amounts of starting materials based on reaction stoichiometry.

Actual Yield

The quantity of product actually collected or isolated from an experimental chemical reaction.

Percent Yield

The ratio of the actual yield to theoretical yield expressed as a percentage: $\text{\% yield} = \frac{\text{Actual yield}}{\text{Theoretical yield}} \times 100\,\%$.

Thermodynamics

The physical study of the relationships and conversions between energy, heat, and work during temperature changes.

Thermochemistry

The branch of thermodynamics that deals specifically with the relationships between chemical changes and heat energy.

Potential Energy

Stored energy possessed by an object due to its position within a field of force or chemical bonds.

Kinetic Energy

The energy possessed by an object or particle due to its motion.

Exothermic Reaction

A chemical reaction or physical process during which the system releases heat energy to its surroundings ($q < 0$).

Endothermic Reaction

A chemical reaction or physical process during which the system absorbs heat energy from its surroundings ($q > 0$).

First Law of Thermodynamics

The law of conservation of energy stating that energy can neither be created nor destroyed; energy lost by the system must be gained by the surroundings ($\Delta E = q + w$).

Enthalpy ($H$)

A thermodynamic state function that provides a measure of the total heat content of a system.

Change in Enthalpy ($\Delta H$)

The net gain or loss of heat energy resulting from a chemical or physical process taking place at constant pressure.

Specific Heat Capacity ($s$)

The quantity of heat required to raise the temperature of one gram of a substance by $1\,^\circ\text{C}$, defined as $s = \frac{q}{m \Delta T}$.

Heat Capacity ($C$)

The amount of heat needed to raise the temperature of an entire object or system by $1\,^\circ\text{C}$, regardless of its mass ($C = \frac{q}{\Delta T}$).

Coffee Cup Calorimeter

A laboratory apparatus used to carry out constant-pressure calorimetry to measure heat flow ($q$) during aqueous chemical or physical processes.