Properties of Solutions Flashcards

Vocabulary flashcards covering key definitions, concentration expressions, factors affecting solubility, and colligative properties from Chemistry II Chapter 1.

Solution

A homogeneous mixture of two or more pure substances uniformly dispersed at the molecular level.

Solvent

The dissolving medium in a solution, which is the most abundant component present.

Solute

The substance that dissolves in a solvent to form a liquid or homogeneous solution.

Miscible Solution

A liquid solution formed by substances that are completely soluble in each other in any proportion.

Immiscible Solution

A mixture of liquids that do not dissolve in each other and form separate distinct layers upon addition.

Solubility ($S$)

The maximum amount of solute that dissolves completely in a given amount of solvent at a particular temperature ($T$).

Dissolution

The dynamic process of dissolving a solute in a solvent to yield a homogeneous solution.

Unsaturated Solution

A solution that contains less than the maximum amount of solute that can dissolve at a given temperature, maintaining the capacity to dissolve more solute.

Saturated Solution

A solution containing the maximum amount of dissolved solute at a given temperature in dynamic equilibrium with undissolved solute ($\text{solute}_{\text{undissolved}} \rightleftharpoons \text{solute}_{\text{dissolved}}$).

Supersaturated Solution

An unstable solution that contains more than the equilibrium amount of dissolved solute; addition of a seed crystal triggers immediate crystallization of the excess solute.

Mole Fraction ($X$)

A temperature-independent concentration ratio defined as the number of moles of a given component divided by the total number of moles of all components in the solution ($X_i = \frac{n_i}{n_{\text{total}}}$).

Mass Percentage

A concentration expression calculated as the mass of solute divided by the total mass of the solution, multiplied by $100\%$ ($\text{Mass \%} = \frac{\text{mass of solute}}{\text{mass of solution}} \times 100\%$).

Parts per Million (ppm)

A concentration unit used for trace amounts of solute, equal to the mass of solute divided by total mass of solution multiplied by $10^6$ (e.g., $1\,\text{mg\,L}^{-1}$ or $1\,\text{mg\,kg}^{-1}$ in water).

Parts per Billion (ppb)

A concentration unit used for extremely small trace amounts, equal to the mass of solute divided by total mass of solution multiplied by $10^9$ (e.g., $1\,\mu\text{g\,L}^{-1}$ or $1\,\mu\text{g\,kg}^{-1}$ in water).

Molarity ($M$)

The amount of solute in moles per liter of total solution ($\text{mol\,L}^{-1}$), which varies with temperature as solution volume expands or contracts.

Molality ($m$)

A temperature-independent expression of solution concentration defined as the number of moles of solute per kilogram of solvent ($\text{mol\,kg}^{-1}$).

Solvation

The process in which a solute particle is surrounded and stabilized by solvent molecules.

Hydration

A specific case of solvation where solute ions or molecules become surrounded specifically by water molecules.

Henry's Law

A gas law stating that at constant temperature, the solubility of a gas ($S_{\text{gas}}$) in a liquid is directly proportional to the partial pressure of that gas ($P_{\text{gas}}$) above the solution ($S_{\text{gas}} = k_H P_{\text{gas}}$).

Solubility Product Constant ($K_{sp}$)

The equilibrium constant for the equilibrium established between an ionic solid solute and its ions in a saturated aqueous solution ($K_{sp} = [\text{M}^{c+}]^a [\text{X}^{d-}]^b$).

Common Ion Effect

The reduction in the solubility of a sparingly soluble ionic salt caused by the addition of a soluble compound containing an ion identical to one in the salt.

Colligative Properties

Solution properties that depend solely on the total number of dissolved solute particles present, regardless of their chemical identity or type.

Vapor Pressure

The pressure exerted by a vapor in dynamic equilibrium with its liquid phase in a closed system at a given temperature.

Raoult's Law

A law stating that the vapor pressure of a solution containing a nonvolatile solute ($P_{\text{solution}}$) equals the mole fraction of the solvent ($X_{\text{solvent}}$) multiplied by the vapor pressure of pure solvent ($P^*_{\text{solvent}}$).

Ideal Solution

A solution that obeys Raoult's Law across all mole fractions, characterized by intermolecular forces between solute and solvent that are comparable to those in pure components.

Non-Ideal Solution

A solution that does not obey Raoult's Law due to differences in intermolecular interactions between solute and solvent molecules, exhibiting positive or negative deviations.

Boiling Point Elevation ($\Delta T_b$)

A colligative property where the boiling point of a solution containing a nonvolatile solute is higher than that of the pure solvent, calculated as $\Delta T_b = i K_b m$.

Freezing Point Depression ($\Delta T_f$)

A colligative property where the freezing point of a solution is lower than that of the pure solvent because solute particles interfere with solvent crystal formation, calculated as $\Delta T_f = -i K_f m$.

Osmosis

The spontaneous net movement of solvent molecules through a semipermeable membrane from a region of lower solute concentration to one of higher solute concentration.

Osmotic Pressure ($\Pi$)

The precise back pressure required to prevent the net flow of solvent across a semipermeable membrane into a solution, calculated as $\Pi = iMRT$.

van 't Hoff Factor ($i$)

The factor representing the total number of particles or ions into which a solute formula unit dissociates when dissolved in a solvent.