General Chemistry 1 Semester Review — Vocabulary Flashcards

Vocabulary flashcards covering core terms and concepts from the first-semester general chemistry topics reflected in the lecture notes.

Stoichiometry

The calculation of reactant and product quantities in a chemical reaction using a balanced equation and mole ratios.

Percent yield

The actual amount of product obtained divided by the theoretical (maximum possible) amount, multiplied by 100%.

Empirical formula

The simplest whole-number ratio of elements in a compound, derived from elemental percentages or masses.

Limiting reactant

The reactant that is consumed first, determining the maximum amount of product that can be formed.

Molar mass

Mass of one mole of a substance (g/mol), used to convert between grams and moles.

Moles

Amount of substance measured in moles (mol); used with molar mass and Avogadro’s number to convert between mass and particles.

Dimensional analysis

A problem-solving technique that uses units as factors to convert between different units or quantities.

Gram-to-mole conversion

Converting grams to moles using the molar mass as a conversion factor.

Balanced equations

Equations rewritten so that the number of atoms of each element is the same on both sides of the equation.

Oxidation number

A formal charge assigned to atoms in a compound to track electron transfer (rules determine typical values).

Oxidizing agent

A substance that oxidizes another species; it is reduced in the reaction.

Reducing agent

A substance that reduces another species; it is oxidized in the reaction.

Ionic vs molecular compounds (nomenclature)

Ionic compounds: name without prefixes (e.g., sodium chloride); molecular compounds: use prefixes (e.g., dinitrogen pentoxide).

Prefixes mono-, di-, tri-,…, deca

Latin/Greek prefixes used in molecular compound naming to indicate the number of atoms of each element.

Nomenclature example (N2O5)

N2O5 is named dinitrogen pentoxide; prefixes indicate the number of atoms of nonmetals in molecular compounds.

Diatomic elements

Elements that naturally exist as molecules of two atoms: H2, N2, O2, F2, Cl2, Br2, I2.

Polyatomic ions (-ite/-ate)

Names of multi-atom ions that end in -ite or -ate (e.g., sulfate, sulfite) depending on oxygen count.

Percent composition

Mass percent of a component: (mass of element in the compound / molar mass of the compound) × 100%.

PV = nRT (Ideal Gas Law)

A fundamental gas law relating pressure, volume, amount of substance, temperature, and the gas constant.

Vapor pressure

Pressure exerted by a vapor in equilibrium with its liquid (or solid) at a given temperature.

Partial pressure

Pressure contributed by a single gas in a mixture; total pressure is the sum of all partial pressures (Dalton’s Law).

Graham’s law of diffusion

Rates of diffusion or effusion are inversely proportional to the square roots of the molar masses.

Mole fraction

The ratio of moles of a component to the total moles in a mixture (Xi = ni / n_total).

Kinetic molecular theory

Gas particles are in constant, random motion; volume of particles is negligible; collisions are elastic; average kinetic energy is proportional to temperature.

Solution stoichiometry

Applying stoichiometric calculations to reactions occurring in solution, using molarity and solution volumes.

Molarity

Concentration of a solute expressed as moles of solute per liter of solution (M = mol/L).

Molality

Concentration of solute as moles per kilogram of solvent (m = mol solute / kg solvent).

Lewis structures

Diagram showing valence electrons as dots/lines to predict bonding, lone pairs, and formal charges.

Molecular geometry

3D arrangement of atoms in a molecule predicted by VSEPR theory (e.g., linear, bent, trigonal planar, tetrahedral).

Enthalpy of reaction (bond energy/heat of formation)

ΔH can be estimated from bond energies or from standard enthalpies of formation for products minus reactants.

Hess’s law

The total enthalpy change of a reaction is the sum of the enthalpies of its steps; state function. 


Intermolecular forces

Forces between molecules: London dispersion, dipole-dipole, and hydrogen bonding (strongest to weakest: H-bonds > dipole-dipole > LDF).

Boiling point

Temperature at which a liquid’s vapor pressure equals the surrounding pressure; influenced by intermolecular forces.

Vapor pressure elevation/boiling point elevation

Colligative effects: adding solute raises boiling point; ΔT_b = Kb m i where i is the van’t Hoff factor.

Freezing point depression

Colligative effect where adding solute lowers the freezing point: ΔT_f = Kf m i.

Osmotic pressure

Pressure required to stop osmosis; π = iMRT for solutions, where i is the van’t Hoff factor, M is molarity, R is the gas constant, T is temperature.

Phase changes

Transitions between solid, liquid, and gas: melting (solid to liquid), freezing (liquid to solid), vaporization (liquid to gas), condensation (gas to liquid), sublimation (solid to gas), deposition (gas to solid); all have characteristic enthalpy changes.

Specific heat capacity (c)

Amount of heat required to raise the temperature of 1 g of a substance by 1°C (J/g·°C). Q = m c ΔT.

Enthalpy of combustion

Heat released/absorbed during combustion; often given per mole of fuel, derived from standard enthalpies of formation. 


Photon energy

Energy of a photon: E = h c / λ, where h is Planck’s constant, c is the speed of light, and λ is wavelength.

Planck’s constant, speed of light

h is 6.626×10^-34 J·s; c is ~3.00×10^8 m/s; appear in equations relating energy, frequency, and wavelength.

Ground state electron configuration

Lowest-energy arrangement of electrons in atoms; follows Aufbau principle and Hund’s rule, used to determine electron distribution.

Quantum numbers (n, l, ml, ms)

n: principal quantum number; l: azimuthal quantum number; ml: magnetic quantum number; ms: spin quantum number; define electron orbitals and spin.

STP molar volume

At standard temperature and pressure (0°C and 1 atm), 1 mole of an ideal gas occupies 22.4 L.

Density of a gas at STP

For a gas, density can be found as M/22.4 L per mole or using ρ = P M / (R T) at a given condition.

Atomic number (Z) and mass number (A)

Z is the number of protons; A = Z + neutrons, total number of nucleons in an atom’s nucleus.

Ion

An atom or molecule with a net electric charge due to losing or gaining electrons.

Energy of a photon (summary)

Photons carry quantized energy: E = h ν = h c / λ; energy depends on wavelength or frequency.