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NotebookLM Chapter Overview
NotebookLM Chapter Overview
7_0_The_Cosmic_Recipe.mp4Textbooks Chapter Summary
Textbooks Chapter Summary
"7.1 Writing and Balancing Chemical Equations
Chemical equations are symbolic representations of chemical and physical changes. Formulas for the substances undergoing the change (reactants) and substances generated by the change (products) are separated by an arrow and preceded by integer coefficients indicating their relative numbers. Balanced equations are those whose coefficients result in equal numbers of atoms for each element in the reactants and products. Chemical reactions in aqueous solution that involve ionic reactants or products may be represented more realistically by complete ionic equations and, more succinctly, by net ionic equations.
Chemical reactions are classified according to similar patterns of behavior. A large number of important reactions are included in three categories: precipitation, acid-base, and oxidation-reduction (redox). Precipitation reactions involve the formation of one or more insoluble products. Acid-base reactions involve the transfer of hydrogen ions between reactants. Redox reactions involve a change in oxidation number for one or more reactant elements. Writing balanced equations for some redox reactions that occur in aqueous solutions is simplified by using a systematic approach called the half-reaction method.
A balanced chemical equation may be used to describe a reaction’s stoichiometry (the relationships between amounts of reactants and products). Coefficients from the equation are used to derive stoichiometric factors that subsequently may be used for computations relating reactant and product masses, molar amounts, and other quantitative properties.
When reactions are carried out using less-than-stoichiometric quantities of reactants, the amount of product generated will be determined by the limiting reactant. The amount of product generated by a chemical reaction is its actual yield. This yield is often less than the amount of product predicted by the stoichiometry of the balanced chemical equation representing the reaction (its theoretical yield). The extent to which a reaction generates the theoretical amount of product is expressed as its percent yield.
The stoichiometry of chemical reactions may serve as the basis for quantitative chemical analysis methods. Titrations involve measuring the volume of a titrant solution required to completely react with a sample solution. This volume is then used to calculate the concentration of analyte in the sample using the stoichiometry of the titration reaction. Gravimetric analysis involves separating the analyte from the sample by a physical or chemical process, determining its mass, and then calculating its concentration in the sample based on the stoichiometry of the relevant process. Combustion analysis is a gravimetric method used to determine the elemental composition of a compound by collecting and weighing the gaseous products of its combustion."
Equations
Equations
Vocabulary Words
Vocabulary Words
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
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