Semester 2 Chemistry Units 5, 6, 7, 8, and 10 Study Guide

A Comprehensive collection of vocabulary terms covering chemical bonding, reactions, stoichiometry, gas laws, and acid-base chemistry based on the lecture syllabus.

chemical bond

A lasting attraction between atoms, ions, or molecules that enables the formation of chemical compounds.

valence electrons

The electrons in the outermost shell, or energy level, of an atom that can participate in the formation of a chemical bond.

octet rule + exceptions

Atoms tend to gain, lose, or share electrons to achieve a full set of eight valence electrons. Exceptions include $H$, $He$, $Li$, $Be$, and $B$ (which can have fewer than 8) and elements in period 3 or higher (which can have more than 8).

ionic bond

A type of chemical bond formed through the electrostatic attraction between oppositely charged ions, typically involving the transfer of electrons from a metal to a nonmetal.

covalent bond

A chemical bond that involves the sharing of electron pairs between atoms, typically between two nonmetals.

metallic bond

The electrostatic attraction between the positively charged atomic nuclei of metal atoms and the delocalized "sea" of conduction electrons.

polar covalent bond

A type of chemical bond where a pair of electrons is unequally shared between two atoms due to differences in electronegativity.

dipole moment

A measure of the separation of positive and negative electrical charges within a molecule, indicating the extent of its overall polarity.

dipole interactions

Intermolecular forces that occur between the positive end of one polar molecule and the negative end of another polar molecule.

intramolecular forces

Forces that hold atoms together within a single molecule, such as ionic, covalent, or metallic bonds.

intermolecular forces

Forces of attraction or repulsion that act between neighboring particles (atoms, molecules, or ions).

ionic compound

A chemical compound composed of ions held together by ionic bonds in a lattice structure.

formula unit

The lowest whole-number ratio of ions represented in an ionic compound.

covalent compound

A chemical compound formed by the sharing of electrons, consisting of atoms held together by covalent bonds.

molecule

A neutral group of two or more atoms held together by chemical bonds, representing the smallest fundamental unit of a covalent compound.

reactant

A substance that takes part in and undergoes change during a chemical reaction.

product

A substance that is formed as a result of a chemical reaction.

combustion reaction

A chemical reaction in which a substance reacts rapidly with oxygen ($O_2$), releasing energy in the form of light and heat.

synthesis reaction

A reaction in which two or more simple substances combine to form a single, more complex product.

decomposition reaction

A chemical reaction in which a single compound breaks down into two or more simpler substances.

single replacement

A reaction where one element replaces another element in a compound.

double replacement

A reaction where the cations and anions of two different ionic compounds switch places to form two new compounds.

precipitate

An insoluble solid that emerges from a liquid solution during a chemical reaction.

mole particles

The quantity of a substance that contains Avogadro's number ($6.022 \times 10^{23}$) of representative particles.

molar mass

The mass of one mole of a substance, usually expressed in units of $g\,mol^{-1}$.

limiting reagent

The reactant in a chemical reaction that is completely consumed first, limiting the amount of product that can be formed.

excess reagent

The reactant that remains in the reaction mixture after the limiting reagent is entirely consumed.

actual yield

The amount of product that is physically obtained from a chemical reaction in a laboratory setting.

theoretical yield

The maximum amount of product that could be formed from given amounts of reactants, based on stoichiometric calculations.

percent yield

The ratio of actual yield to theoretical yield, calculated as $\frac{\text{actual yield}}{\text{theoretical yield}} \times 100$.

empirical formula

Refers to the simplest whole-number ratio of atoms of each element present in a compound.

pressure

The amount of force exerted per unit area of a surface.

temperature

A measure of the average kinetic energy of the particles in a sample of matter, often measured in Kelvin ($K$) for gas laws.

volume

The amount of three-dimensional space occupied by a gas or substance.

STP

Standard Temperature and Pressure, defined as $0\,^{\circ}\text{C}$ ($273.15\,K$) and $1\,\text{atm}$ of pressure.

acid

A chemical species that donates protons or hydrogen ions ($H^+$) and/or accepts electrons.

base

A chemical species that accepts protons or hydrogen ions ($H^+$) and/or donates electrons.

Bronsted-Lowry acid

A substance that can donate a hydrogen ion ($H^+$) to another substance.

Bronsted-Lowry base

A substance that can accept a hydrogen ion ($H^+$) from another substance.

pH

A numeric scale used to specify the acidity of an aqueous solution, calculated as $-\log_{10}([H^+])$. environment.

pOH

A measure of hydroxide ion concentration in a solution, calculated as $-\log_{10}([OH^-])$. environment.

7 diatomic molecules

Elements that naturally exist as molecules composed of two atoms: $H_2$, $N_2$, $O_2$, $F_2$, $Cl_2$, $Br_2$, and $I_2$.

Greek prefixes 1–10

Prefixes used to name covalent compounds: 1 (mono-), 2 (di-), 3 (tri-), 4 (tetra-), 5 (penta-), 6 (hexa-), 7 (hepta-), 8 (octa-), 9 (nona-), 10 (deca-).