Chemistry: The Central Science Chapter 4

Aqueous solution

A solution in which water is the solvent.

Solvent

The dissolving medium of a solution; it is normally the component of a solution present in the greater concentration.

Solute

A substance dissolved in a solvent to form a solution; it is normally the component of a solution present in the smaller amount.

Electrolyte

A solute that produces ions in solution; an electrolytic solution conduct an electric current.

Nonelectrolyte

A substance that does not ionize in water and consequently gives a nonconducting solution.

Solvation

The clustering of solvent molecules around a solute particle.

Strong electrolyte

A substance (strong acids, strong bases, and most salts) that is completely ionized in solution.

Weak electrolyte

A substance that only partly ionizes in water.

Chemical equilibrium

A state of dynamic balance in which the rate of formation of the products of a reaction from the reactants equals the rate of formation of the reactants from the products; at equilibrium the concentrations of the reactants and products remain constant.

Precipitation reaction

A reaction that occurs between substances in solution in which one of the products is insoluble.

Precipitate

An insoluble substance that forms in, and separates from, a solution.

Solubility

The amount of a substance that dissolves in a given quantity of solvent at a given temperature to form a saturated solution.

Exchange (metathesis) reaction

A reaction between compounds that when written as a molecular equation appears to involve the exchange of ions between the two reactants.

Metathesis (exchange) reaction

A reaction in which two substances react through an exchange of their component ions: AX + BY -> AY + BX. Precipitation and acid-base neutralization reactions are examples of metathesis reactions.

Molecular equation

A chemical equation in which the formula for each substance is written without regard for whether it is an electrolyte or a nonelectrolyte.

Complete ionic equation

A chemical equation in which dissolved strong electrolytes (such as dissolved ionic compounds) are written as separate ions.

Spectator ions

Ions that go through a reaction unchanged and that appear on both sides of the complete ionic equation.

Net ionic equation

A chemical equation for a solution reaction in which soluble strong electrolytes are written as ions and spectator ions are omitted.

Acid

A substance that is able o donate a H+ ion (a proton) and here increase the concentration of H+(aq) when it dissolves in water.

Base

A substance that is an H+ acceptor, a base produces an excess of OH- (aq) ions when it dissolves in water.

Strong acid

An acid that ionizes completely in water.

Strong base

A base that ionizes completely in water.

Weak acid

An acid that only partially ionizes in water.

Weak base

A base that only partially ionizes in water.

Neutralization reaction

A reaction in which an acid and a base react in stoichiometrically equivalent amounts; the neutralization reaction between an acid and a metal hydroxide produces water and a salt.

Salt

An ionic compound formed by replacing one or more hydrogens of an acid by other cations.

Oxidation-reduction (redox) reaction

A chemical reaction in which the oxidation states of certain atoms change.

Redox (oxidation-reduction) reaction

A reaction in which certain atoms undergo changed in oxidation states. The substance increasing in oxidation state is oxidized; the substance decreasing in oxidation state is reduced.

Oxidation

A process in which a substance loses one or more electrons.

Reduction

A process in which a substance gains one or more electrons.

Oxidation number (oxidation state)

A positive or negative whole number assigned to an element in a molecule or ion on the basis of a set of formal rules; to some degree it reflects the positive or negative character of that atom.

Activity series

A list of metals in order of decreasing ease of oxidation.

Concentration

The quantity of solute present in a given quantity of solvent or solution.

Molarity

The concentration of a solution expressed as moles of solute per liter of solution; abbreviated M.

Dilution

The process of preparing a less concentrated solution from a more concentrated one by adding solvent.

Titration

The process of reacting a solution of unknown concentration with one of known concentration.

Standard solution

A solution of known concentration.

Equivalence point

The point in a titration at which the added solute reacts completely with the solute present in the solution.

Indicator

A substance added to a solution that changed color when the added solute had reacted with all the solute present in solution.