General Chemistry (CHEM 111): Chemical Reactions, Stoichiometry, and Atomic Structure

Comprehensive vocabulary flashcards covering aqueous chemical reactions, solution stoichiometry, electrolytes, acid-base neutralizations, redox chemistry, quantum mechanical models, electromagnetic radiation, and atomic orbitals for CHEM 111.

Solute

The substance dissolved in a solution, typically present in a smaller quantity than the solvent.

Solvent

The substance in which dissolution takes place in a homogeneous mixture; generally present in the largest amount.

Aqueous Solution

A solution in which water acts as the solvent.

Electrolyte

A substance that dissolves in water to produce hydrated ions, thereby increasing the electrical conductivity of the solution.

Nonelectrolyte

A substance that dissolves in water as intact, neutral molecules without forming ions and does not conduct electricity.

Strong Electrolyte

A compound that dissociates or ionizes $100\%$ completely in water to yield mobile ions.

Weak Electrolyte

A compound that ionizes or dissociates only partially (less than $100\%$) in water, resulting in relatively few mobile ions in solution.

Soluble Compound (Solubility Rule Standard)

An ionic compound defined as dissolving to the extent of $1\,g$ or more per $100\,g$ of water.

Metathesis Reaction (Exchange Reaction)

A double displacement chemical reaction where reacting ionic compounds swap ion partners according to the pattern $AB + CD \rightarrow CB + AD$.

Precipitation Reaction

An exchange reaction occurring in an aqueous medium that yields at least one insoluble solid product known as a precipitate.

Spectator Ions

Ions that do not actively participate in a chemical reaction and remain unchanged on both reactant and product sides of a complete ionic equation.

Net Ionic Equation (NIE)

A chemical equation displaying only the specific ionic and molecular species that directly participate in a reaction, with all spectator ions omitted.

Acid

A chemical species that generates hydronium ions ($H^+(aq)$ or $H_3O^+$) when dissolved in water.

Base

A chemical species that generates hydroxide ions ($OH^-(aq)$) when dissolved in water.

Neutralization Reaction

A reaction between an acid and a base that produces water ($H_2O$) and a salt composed of a cation and an anion.

Molarity ($M$)

A quantitative measure of concentration defined as the number of moles of solute dissolved per liter of solution ($\text{moles of solute} / \text{liters of solution}$).

Stock Solution

A concentrated initial solution from which more dilute solutions of lower concentration are prepared by adding solvent ($M_{\text{stock}} V_{\text{stock}} = M_{\text{dil}} V_{\text{dil}}$).

$$pH$$

A logarithmic measure of the hydronium ion concentration in an aqueous solution, defined as $pH = -\log[H_3O^+]$.

Equivalence Point

The point during a titration at which the reacting amounts of acid and base precisely match the stoichiometric ratio required by the balanced chemical equation.

Oxidation

The process involving the loss of one or more electrons from a chemical species, resulting in an increase in its oxidation number.

Reduction

The process involving the gain of one or more electrons by a chemical species, resulting in a decrease (more negative) in its oxidation number.

Reducing Agent (Reductant)

The reactant in a redox process that donates electrons to another species, thereby becoming oxidized.

Oxidizing Agent (Oxidant)

The reactant in a redox process that accepts electrons from another species, thereby becoming reduced.

Oxidation Number (Oxidation State)

A positive or negative whole number assigned to an atom in a compound or ion representing the charge it would hold if electron transfer were complete.

Aufbau Principle

The rule establishing that atomic orbitals fill with electrons starting from the lowest available energy levels before occupying higher levels.

Hund's Rule

The rule dictating that electrons occupy degenerate orbitals singly with identical parallel spins before pairing with opposite spins in any single orbital.

Pauli Exclusion Principle

The quantum rule specifying that no two electrons in an atom can have the same four quantum numbers, limiting each orbital to a maximum of two electrons with opposing spins.

Isoelectronic

A descriptor for chemical species (atoms or ions) having identical total electron counts and identical ground-state electron configurations.

Diamagnetic

The magnetic condition of an atom, ion, or molecule containing exclusively paired electrons in its electronic ground state, causing it not to be attracted by a magnetic field.

Lyman Series

The spectral emission series of the hydrogen atom produced when electrons transition from higher energy levels ($n > 1$) down to the ground state ($n = 1$).

Photon

An indivisible, discrete packet of electromagnetic radiation with energy proportional to frequency ($E_{\text{photon}} = h\nu = \frac{hc}{\lambda}$).

Wavelength ($\lambda$)

The physical distance between successive crests or corresponding identical points in adjacent cycles of an electromagnetic wave.

Frequency ($\nu$)

The number of complete wave cycles or oscillations passing a stationary point in space per second, expressed in units of hertz ($\text{Hz}$) or $\text{s}^{-1}$.

Photoelectric Effect

The ejection of electrons from a material's surface caused when incoming photons carry sufficient quantum energy (short enough wavelength) to dislodge them.

Atomic Line Spectrum

A distinct series of discrete wavelengths emitted by thermally or electrically excited gas-phase atoms, evidencing the quantization of electronic energy levels.

Quantized Energy

Energy that exists exclusively at specific, discrete, fixed values (quanta) rather than along an arbitrary continuous spectrum.

Ground State

The lowest allowable potential energy configuration of an electron in an atom, defined as $n = 1$ for hydrogen.

Excited State

Any atomic state in which an electron has absorbed energy and moved to an energy level higher than its ground state ($n > 1$).

Atomic Orbital

A one-electron spatial wavefunction ($\psi$) where the square of the amplitude ($|\psi|^2$) represents the probability density of detecting an electron in a specific region of space.

Principal Quantum Number ($n$)

The integer quantum number ($n = 1, 2, 3, \dots$) identifying the primary electron shell, orbital size, and main energy level in an atom.

Angular Momentum Quantum Number ($\ell$)

The quantum number taking integer values from $0$ to $n - 1$ that specifies the subshell and defines the three-dimensional geometric shape of an orbital.

Magnetic Quantum Number ($m_\ell$)

The quantum number with integer values ranging from $-\ell$ to $+\ell$ ($2\ell + 1$ allowed values) indicating the spatial orientation of an orbital in three dimensions.

Electron Spin Quantum Number ($m_s$)

The quantum number designating the intrinsic angular momentum or spin orientation of an electron, taking values of $+\frac{1}{2}$ or $-\frac{1}{2}$.