Chemistry: Compounds, Bonding, & Reactions

Vocabulary flashcards covering chemical bonding, compound naming, acids and bases, physical and chemical changes, reaction types, and experimental variables.

Octet Rule

The rule stating that atoms gain, lose, or share electrons to achieve a full outer energy level ($8$ valence electrons), matching the electron configuration of the nearest noble gas to maximize stability.

Cation

A positively charged ion formed when metal atoms lose valence electrons (e.g., $Mg^{2+}$, $Al^{3+}$).

Anion

A negatively charged ion formed when nonmetal atoms gain valence electrons, causing the element suffix to change to "-ide" (e.g., chlorine becomes chloride, $Cl^{1-}$).

Net Charge Calculation

The formula used to calculate an ion's charge: $\text{Net Charge} = \text{Number of Protons} - \text{Number of Electrons}$.

Ionic Bonding

A chemical bond formed between a metal and a nonmetal involving the complete transfer of electrons (giving/taking), resulting in a crystal lattice structure of alternating cations and anions.

Covalent (Molecular) Bonding

A chemical bond formed between nonmetals involving the mutual sharing of electron pairs, resulting in discrete individual molecules.

Multivalent Ionic Compounds

Ionic compounds containing transition metals that can form cations with multiple possible charges, specified using Roman numerals in parentheses immediately following the metal name (e.g., Iron(II) oxide = $FeO_{(s)}$).

Polyatomic Ion

A covalently bonded group of nonmetal atoms carrying an overall charge that acts as a single unit during chemical reactions.

Parentheses Rule for Polyatomic Ions

The chemical formula rule stating that a polyatomic ion is enclosed in parentheses only if a subscript multiplier greater than $1$ is required.

Greek Prefixes for Molecular Compounds

Prefixes used in naming molecular compounds: $1 = \text{mono-}$, $2 = \text{di-}$, $3 = \text{tri-}$, $4 = \text{tetra-}$, $5 = \text{penta-}$, $6 = \text{hexa-}$, $7 = \text{hepta-}$, $8 = \text{octa-}$, $9 = \text{nona-}$, and $10 = \text{deca-}$.

Acid

A substance that produces hydrogen ions ($H^+$) in aqueous solutions with a $pH < 7$, turns litmus paper red, tastes sour, and is corrosive.

Base

A substance that produces hydroxide ions ($OH^-$) in aqueous solutions with a $pH > 7$, turns litmus paper blue, tastes bitter, feels slippery, and is corrosive.

Hydro_____ic Acid Rule

The acid naming rule where hydrogen combined with an anion ending in "-ide" becomes "hydro_____ic acid" in aqueous solution (e.g., hydrogen chloride becomes hydrochloric acid, $HCl_{(aq)}$).

_____ic Acid Rule

The acid naming rule where hydrogen combined with a polyatomic anion ending in "-ate" becomes "_____ic acid" in aqueous solution (e.g., hydrogen nitrate becomes nitric acid, $HNO_{3(aq)}$).

_____ous Acid Rule

The acid naming rule where hydrogen combined with a polyatomic anion ending in "-ite" becomes "_____ous acid" in aqueous solution (e.g., hydrogen chlorite becomes chlorous acid, $HClO_{2(aq)}$).

Electrical Conductivity of Ionic Compounds

The property of ionic compounds conducting electricity in liquid or aqueous solution states due to free-floating ions, while remaining non-conductive as a solid.

Electrical Conductivity of Molecular Compounds

The property of molecular compounds being non-conductive in all physical states because they dissolve as whole neutral molecules.

Very Soluble (aq)

Describes a compound that dissolves significantly in water, labeled as aqueous ($aq$), allowing free ions to flow and electricity to conduct.

Slightly Soluble (s)

Describes a compound that does not dissolve appreciably in water, forming a solid precipitate ($s$).

Precipitate

An insoluble solid formed during a double replacement reaction between aqueous solutions.

Physical Change

A change that alters the form or state of a substance without changing its chemical identity, and is reversible (e.g., melting ice, dissolving sugar).

Chemical Change

A process that transforms substances into entirely new chemical entities with distinct properties, indicated by odor change, temperature exchange, gas bubble formation, color change, light production, or precipitate formation.

Formation (Synthesis) Reaction

A chemical reaction where elements combine to form a compound, following the general equation $A + B \rightarrow AB$.

Decomposition Reaction

A chemical reaction where a compound breaks down into its constituent elements, following the general equation $AB \rightarrow A + B$.

Single Replacement Reaction

A chemical reaction where an element and a compound react to form a new element and a new compound, following the general equation $A + BC \rightarrow B + AC$.

Double Replacement Reaction

A chemical reaction where two compounds react to form two new compounds, following the general equation $AB + CD \rightarrow AD + CB$.

Hydrocarbon Combustion Reaction

A chemical reaction where a hydrocarbon reacts with oxygen gas to yield carbon dioxide gas and water vapor, represented by $\text{Hydrocarbon} + O_{2(g)} \rightarrow CO_{2(g)} + H_2O_{(g)}$.

Independent Variable

The single factor intentionally altered or varied by the experimenter to test its effect.

Dependent Variable

The factor measured or observed in an experiment to determine the outcome of changing the independent variable.

Controlled Variables

All parameters kept strictly identical across experimental trials to guarantee a fair test.