Unit 1: Foundations of Matter & Stoichiometry

Comprehensive vocabulary flashcards covering the key terms, principles, models, and quantitative definitions from Unit 1: Foundations of Matter & Stoichiometry.

Filtration

A physical separation technique used to separate an insoluble solid residue from a liquid filtrate.

Phase Change at Constant Temperature

A transition between states of matter where kinetic energy stays constant while potential energy changes.

Charles's Law

A gas law stating that the volume of an ideal gas is directly proportional to its absolute temperature at constant pressure, represented as $\frac{V_1}{T_1} = \frac{V_2}{T_2}$.

Real Gas Deviation Conditions

The conditions of high pressure (where particle volume becomes significant) and low temperature (where intermolecular forces become significant) under which real gases deviate most from ideal gas behavior.

Kinetic Model of a Liquid

A state of matter where particles are closely packed in a random arrangement with translational movement, sliding over each other.

Kinetic Model of a Gas

A state of matter where particles are widely spaced, randomly arranged, and move rapidly in continuous straight lines.

Boiling (Energy Dynamics)

A phase change during which added thermal energy is consumed exclusively to overcome intermolecular attractive forces (increasing potential energy) rather than increasing particle speed (kinetic energy and temperature remain constant).

Relative Atomic Mass ($A_r$)

The weighted average mass of the atoms of an element taking into account isotopic abundances, calculated as $\sum (\text{isotopic mass} \times \text{fractional abundance})$.

Empirical Formula

The simplest whole-number ratio of atoms of each element present in a chemical compound.

Molecular Formula

The formula that indicates the actual number of atoms of each element present in a molecule, expressed as an integer multiple of the empirical formula: $\text{Molecular Formula} = (\text{Empirical Formula})_x$.

Limiting Reactant

The reactant that is entirely consumed first in a chemical reaction, thereby determining and limiting the maximum theoretical amount of product that can be formed.

Percentage Yield

The ratio of the actual yield of product obtained experimentally to the maximum calculated theoretical yield, expressed as: $\text{Percentage yield} = \left(\frac{\text{actual mass}}{\text{theoretical mass}}\right) \times 100\%$.

Heterogeneous Mixture

A mixture containing non-uniform composition and distinct phases, such as granite rock composed of quartz, feldspar, and mica.

Homogeneous Mixture

A uniform mixture possessing a single phase throughout, such as air, vinegar, or steel.

Magnetic Separation

A physical separation method exploiting ferromagnetism to extract magnetic materials (such as iron filings) directly without chemical modification or solvent addition.

Kinetic Molecular Theory (Temperature Relationship)

The principle stating that the average kinetic energy ($E_k$) of particles is directly proportional to absolute temperature in Kelvin ($T$).

Giant Ionic Lattice

A continuous three-dimensional network of alternating ions that does not form discrete molecules, meaning chemical formulas like $CaCl_2$ represent empirical formula units rather than molecular units.

Standard Solution Preparation

The quantitative process of weighing a pure solute accurately on an analytical balance, dissolving it in distilled water, transferring it with washings into a volumetric flask, and diluting until the meniscus touches the calibration line.

Dilution Law

The stoichiometric formula relating initial and final concentrations and volumes when a solution is diluted: $c_1V_1 = c_2V_2$.

Mass Concentration ($\rho$)

The mass of solute per unit volume of solution, calculated as the product of molar concentration ($c$) and molar mass ($M$): $\rho = c \times M$.

Percentage Purity

The proportion of pure substance in an impure sample, determined by: $\text{Percentage Purity} = \left(\frac{\text{mass of pure substance}}{\text{total mass of sample}}\right) \times 100\%$.

Condensation (Energy Dynamics)

A phase change where temperature and kinetic energy remain constant because the energy released during intermolecular bond formation compensates for the cooling energy removed.