Chp 4 Stoichiometry of Chemical Reactions

acid

substance that produces H₃O⁺ when dissolved in water

acid-base reaction

reaction involving the transfer of a hydrogen ion between reactant species

actual yield

amount of product formed in a reaction

analyte

chemical species of interest

balanced equation

chemical equation with equal numbers of atoms for each element in the reactant and product

base

substance that produces OH⁻ when dissolved in water

buret

device used for the precise delivery of variable liquid volumes, such as in a titration analysis

chemical equation

symbolic representation of a chemical reaction

coefficient

number placed in front of symbols or formulas in a chemical equation to indicate their relative amount

combustion analysis

gravimetric technique used to determine the elemental composition of a compound via the collection and weighing of its gaseous combustion products

combustion reaction

vigorous redox reaction producing significant amounts of energy in the form of heat and, sometimes, light

complete ionic equation

chemical equation in which all dissolved ionic reactants and products, including spectator ions, are explicitly represented by formulas for their dissociated ions

end point

measured volume of titrant solution that yields the change in sample solution appearance or other property expected for stoichiometric equivalence (see equivalence point)

equivalence point

volume of titrant solution required to react completely with the analyte in a titration analysis; provides a stoichiometric amount of titrant for the sample’s analyte according to the titration reaction

excess reactant

reactant present in an amount greater than required by the reaction stoichiometry

gravimetric analysis

quantitative chemical analysis method involving the separation of an analyte from a sample by a physical or chemical process and subsequent mass measurements of the analyte, reaction product, and/or sample

half-reaction

an equation that shows whether each reactant loses or gains electrons in a reaction.

indicator

substance added to the sample in a titration analysis to permit visual detection of the end point

insoluble

of relatively low solubility; dissolving only to a slight extent

limiting reactant

reactant present in an amount lower than required by the reaction stoichiometry, thus limiting the amount of product generated

molecular equation

chemical equation in which all reactants and products are represented as neutral substances

net ionic equation

chemical equation in which only those dissolved ionic reactants and products that undergo a chemical or physical change are represented (excludes spectator ions)

neutralization reaction

reaction between an acid and a base to produce salt and water

oxidation

process in which an element’s oxidation number is increased by loss of electrons

oxidation number

(also, oxidation state) the charge each atom of an element would have in a compound if the compound were ionic

oxidation-reduction reaction

(also, redox reaction) reaction involving a change in oxidation number for one or more reactant elements

oxidizing agent

(also, oxidant) substance that brings about the oxidation of another substance, and in the process becomes reduced

percent yield

measure of the efficiency of a reaction, expressed as a percentage of the theoretical yield

precipitate

insoluble product that forms from reaction of soluble reactants

precipitation reaction

reaction that produces one or more insoluble products; when reactants are ionic compounds, sometimes called double-displacement or metathesis

product

substance formed by a chemical or physical change; shown on the right side of the arrow in a chemical equation

quantitative analysis

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

reactant

substance undergoing a chemical or physical change; shown on the left side of the arrow in a chemical equation

reducing agent

(also, reductant) substance that brings about the reduction of another substance, and in the process becomes oxidized

reduction

process in which an element’s oxidation number is decreased by gain of electrons

salt

ionic compound that can be formed by the reaction of an acid with a base that contains a cation and an anion other than hydroxide or oxide

single-displacement reaction

(also, replacement) redox reaction involving the oxidation of an elemental substance by an ionic species

solubility

the extent to which a substance may be dissolved in water, or any solvent

soluble

of relatively high solubility; dissolving to a relatively large extent

spectator ion

ion that does not undergo a chemical or physical change during a reaction, but its presence is required to maintain charge neutrality

stoichiometric factor

ratio of coefficients in a balanced chemical equation, used in computations relating amounts of reactants and products

stoichiometry

relationships between the amounts of reactants and products of a chemical reaction

strong acid

acid that reacts completely when dissolved in water to yield hydronium ions

strong base

base that reacts completely when dissolved in water to yield hydroxide ions

theoretical yield

amount of product that may be produced from a given amount of reactant(s) according to the reaction stoichiometry

titrant

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

titration analysis

quantitative chemical analysis method that involves measuring the volume of a reactant solution required to completely react with the analyte in a sample

weak acid

acid that reacts only to a slight extent when dissolved in water to yield hydronium ions

weak base

base that reacts only to a slight extent when dissolved in water to yield hydroxide ions