CHEM 1123 – Unit 5 Part 1: Solutions, Acids & Bases

Vocabulary flashcards summarizing the essential terms and definitions from the CHEM 1123 Unit 5 Part 1 lecture on solutions, solubility, and electrolytes.

Solution

A homogeneous mixture of two or more substances consisting of a solvent and one or more solutes; its formation is a physical process.

Solvent

The component of a solution present in the greatest amount; it dissolves the solute(s).

Solute

The substance(s) dissolved in a solvent; spreads evenly, cannot be filtered out, can be separated by evaporation, and may impart color.

Homogeneous Mixture

A mixture with uniform composition and properties throughout, such as a solution.

Water (H₂O)

The most common solvent; a polar, V-shaped molecule (104.5° bond angle) capable of hydrogen bonding.

Polar Molecule

A molecule with partially positive and partially negative ends (dipoles), e.g., H₂O.

Nonpolar Molecule

A molecule lacking oppositely charged ends; either all non-polar bonds or symmetrical charge distribution (e.g., CH₄, CO₂).

Hydrogen Bond

An intermolecular attraction between a hydrogen atom bonded to N, O, or F and a lone pair on another electronegative atom; gives water its high boiling point.

Ionic Compound

A substance composed of oppositely charged ions arranged in a crystal lattice.

Crystal Lattice

The orderly three-dimensional arrangement of ions in an ionic solid.

Aqueous Ion (aq)

An ion surrounded by water molecules in solution, indicated by the (aq) symbol, e.g., Na⁺(aq).

Like Dissolves Like

Rule stating that solutes dissolve best in solvents with similar polarity: polar dissolves polar/ionic; nonpolar dissolves nonpolar.

Strong Electrolyte

A substance that dissociates 100 % into ions in water, producing solutions that conduct electricity well.

Weak Electrolyte

A substance that partially dissociates in water, yielding a solution with few ions and establishing an equilibrium.

Nonelectrolyte

A substance that dissolves in water as neutral molecules and produces no ions, thus no electrical conductivity.

Solubility

The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature, expressed as g solute/100 g solvent.

Henry’s Law

The solubility of a gas in a liquid is directly proportional to the pressure of that gas above the liquid.

Unsaturated Solution

A solution containing less than the maximum solute at a given temperature; more solute can dissolve.

Saturated Solution

A solution holding the maximum solute at a given temperature, with excess undissolved solute present.

Concentration

A measure of the amount of solute dissolved in a specific amount of solution, expressed in various units (%, M, mEq/L, etc.).

Percent by Mass (% m/m or w/w)

Mass of solute per 100 g of solution: % = (g solute / g solution) × 100.

Percent by Volume (% v/v)

Volume of liquid solute per 100 mL of solution: % = (mL solute / mL solution) × 100.

Mass/Volume Percent (% m/v or w/v)

Mass of solute per 100 mL of solution: % = (g solute / mL solution) × 100.

Equivalent (Eq)

Amount of an ion that supplies 1 mole of electrical charge; e.g., 1 mol Na⁺ = 1 Eq, 1 mol Ca²⁺ = 2 Eq.

Milliequivalent (mEq)

1/1000 of an equivalent; used for ion concentrations in body fluids (1000 mEq = 1 Eq).

Conversion Factor (from Concentration)

A ratio derived from a concentration expression that enables calculation of mass, volume, or amount of solute or solution.