AP Chemistry - Chapter 4: Reactions in Aqueous Solutions

Solution

A homogeneous mixture of two or more substances

Solute

The substance present in a smaller amount that is being dissolved

Solvent

The substance present in a larger amount in which the solute dissolves in

Solubility

The maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature and pressure

Aqueous Solution

A solution in which the solute initially is a liquid or a solid and the solvent is water(In Chemical Equations, describe an aqueous compound with the subscript (aq)).

Polar Molecule

A molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

• (Ex: Water)

Electrical Conductivity

How well a substance allows electricity to flow through it

Electrolyte

A substance that, when dissolved in water, results in a solution that can conduct electricity

Strong Electrolyte

A solution in which a large portion of the solute exists as ions allowing for electrical conductivity

Weak Electrolyte

A solution that conducts electricity poorly because only a fraction of the solute exists as ions

Nonelectrolyte

A substance that does not conduct electricity when dissolved in water

Hydration

The process in which an ion is surrounded by water molecules arranged in a specific manner

Ionization

The separation of an atom or molecule (particularly acids and bases) into positive and negative ions.

Dissociation

The separation of ions that occurs when an ionic compound dissolves

Precipitation Reaction

A reaction in which an insoluble substance forms and separates from the solution

Precipitate

An insoluble solid that separates from a solution during a chemical reaction

Molecular Equation

Chemical equation in which the formulas of the compounds are written as though all species existed as molecules or whole units

(Complete) Ionic Equation

A chemical equation that shows dissolved species as free ions

Spectator Ions

Ions that are not involved in the overall reaction

Net Ionic Equation

A chemical equation that shows only the species that actually take part in the reaction

Acid

A substance that increases the hydrogen ion concentration of a solution

• Have a sour taste

• Aqueous Acid Solutions conduct electricity

Base

A substance that decreases the hydrogen ion concentration in a solution

• Have a bitter taste

• Feel slippery

• Aqueous Base Solutions conduct electricity

Strong Acid

An acid that ionizes completely in aqueous solution

Strong Base

A base that completely dissociates into metal ions and hydroxide ions in aqueous solution

Weak Acid

An acid that is only slightly ionized in an aqueous solution

Weak Base

A base that does not dissociate completely into ions in a solution

Arrhenius Acid

A substance that increases the concentration of hydronium ions (or H+) in an aqueous solution

Arrhenius Base

a substance that increases the concentration of hydroxide ions in an aqueous solution

Bronsted-Lowry Acid

A molecule or ion that is a proton donor

Bronsted-Lowry Base

A molecule or ion that is a proton acceptor

Neutralization Reaction

A reaction in which an acid and a base react in an aqueous solution to produce a salt and water

Monoprotic Acid

An acid that can donate only one proton (hydrogen ion) per molecule

Diprotic Acid

An acid that can donate two protons per molecule

Triprotic Acid

An acid able to donate three protons per molecule

Redox Reaction (Oxidation-Reduction Reactions)

Chemical reaction that transfers electrons between reactants

Reducing Agent

A substance that donates electrons in a reaction, becoming oxidized

Oxidizing Agent

A substance that accepts electrons in a reaction, becoming reduced

Molarity (Molar Concentration)

The number of moles of solute per liter of solution:

M = n/V

Dilution

The process of adding solvent (typically water) to lower the concentration of solute in a solution

Quantitative Analysis

The determination of the amount or concentration of a substance in a sample

Gravimetric Analysis

An analytical technique based on the measurement of mass

Volumetric Analysis

A technique for determining the amount of a certain substance by doing a titration

Titration

A solution of known concentration is added gradually to another solution of unknown concentration until the chemical reaction between the two solutions is complete to determine the concentration of the unknown solution

Analyte

A solution of unknown concentration that is being identified

Titrant/ Standard Solution

A solution containing a known concentration of substance that will react with the analyte in a titration analysis

Equivalence Point (Stoichiometric Point)

The point at which the acid has completely reacted with or been neutralized by the base

• (The point in the titration where enough titrant has been added to react exactly with the analyte)

Endpoint

The point in a titration where the acid and base have completely reacted with one another, being usually accompanied by an indicator's change in color

Indicator

Substances that have distinctly different colors in acidic and basic media

Phenopthalien

A commonly used indicator compound that is colorless in acidic and neutral solutions but reddish pink in basic solutions

Acid-Base Titration

The process by which an acid of known concentration is added to a base of unknown concentration (or vice-versa) until a neutral pH is reached so as to determine the unknown concentration