CHM 30 Chapter 4: Reactions in Aqueous Solutions

Vocabulary flashcards covering key concepts from CHM 30 Chapter 4: Reactions in Aqueous Solutions.

Solution

A homogeneous mixture of two or more substances.

Solvent

The component present in the greatest amount (in moles); the medium that dissolves the solute.

Solute

Substance(s) dissolved in the solvent.

Aqueous solution

A solution in which water is the solvent.

Dissociation

Process by which soluble ionic compounds separate into ions in water.

Hydration shell

Water molecules surrounding dissolved ions to stabilize them.

Molarity (M)

Moles of solute per liter of solution (mol/L).

Concentration brackets [ ]

Notation for concentration; e.g., [Ag+] = 0.1 M.

Dilution

Process of lowering concentration by adding solvent; moles remain constant.

M1V1 = M2V2

Dilution equation: initial concentration and volume relate to final concentration and volume.

Stock solution

A concentrated solution used to prepare solutions of lower concentration.

Beer's Law

A = ε b c; absorbance is proportional to concentration of absorbing species.

Molar absorptivity (ε)

A constant that describes how strongly a species absorbs light at a given wavelength.

Electrolyte

Substance that increases conductivity when dissolved in water by forming ions.

Strong electrolyte

Completely ionizes in solution (e.g., soluble salts, strong acids/bases).

Weak electrolyte

Partially ionizes in solution; only weakly conducts electricity.

Nonelectrolyte

Does not increase conductivity; does not form ions in solution.

Conductivity

Ability of a solution to conduct electricity; increases with more ions.

Hydronium ion (H3O+)

H+ in water, formed when a proton associates with water.

Bronsted-Lowry acid

A substance that donates a proton (H+).

Bronsted-Lowry base

A substance that accepts a proton (H+).

Acid-base reaction

Reaction involving transfer of protons between acids and bases.

Neutralization

Acid-base reaction that produces water and a salt.

Salt

Ionic compound formed from the cation of a base and the anion of an acid.

Spectator ion

Ion that does not participate in the chemical reaction and remains in solution.

Molecular equation

Equation written with all species as complete formulas (no ions).

Total ionic equation

Equation showing all strong electrolytes as ions; other species remain as compounds.

Net ionic equation

Equation that eliminates spectator ions to show only species that change.

Precipitation reaction

Reaction that forms an insoluble solid (precipitate) when solutions are mixed.

Precipitate

The insoluble solid produced in a precipitation reaction.

Solubility rules

Guidelines indicating which compounds are soluble or insoluble in water.

Solubility

Extent to which a substance dissolves in a solvent.

Redox reaction

Reaction involving transfer of electrons; oxidation and reduction occur.

Oxidation

Loss of electrons; oxidation number increases.

Reduction

Gain of electrons; oxidation number decreases.

Oxidizing agent

Substance that is reduced and causes another species to be oxidized.

Reducing agent

Substance that is oxidized and causes another species to be reduced.

Oxidation number

Formal charge assigned to atoms to track electron transfer; rules include F always -1 (except F2), O usually -2, H usually +1, neutral molecules sum to zero.

Monoprotic

An acid with one acidic hydrogen per molecule.

Diprotic

An acid with two acidic hydrogens per molecule.

Triprotic

An acid with three acidic hydrogens per molecule.

Amphiprotic

A species that can act as both an acid and a base.