saturated solution A solution in which one has
dissolved the maximum amount of solute per
given amount of solvent at a given temperature is
called a saturated solution.
Second Law of Thermodynamics The Second Law
of Thermodynamics states that all processes that
occur spontaneously move in the direction of an
increase in entropy of the universe (system +
surroundings).
semipermeable membrane A semipermeable mem-
brane is a thin porous film that allows the passage
of solvent molecules but not solute particles.
shells The electrons in an atom are located in various
energy levels or shellsthat are located at different
distances from the nucleus.
SI system The system of units used in science is the
SI system (Système International), which is
related to the metric system.
Sigma (σ) bonds Sigma bonds have the orbital over-
lap on a line drawn between the two nuclei.
simple cubic unit cell The simple cubic unit cell has
particles located at the corners of a simple cube.
single displacement (replacement) reactions
Single displacement reactions are reactions in
which atoms of an element replace the atoms of
another element in a compound.
solidA solid is a state of matter that has both a def-
inite shape and a definite volume.
solubility product constant (Ksp) The solubility
product constant is the equilibrium constant
associated with sparingly soluble salts and is the
product of the ionic concentrations, each one
raised to the power of the coefficient in the
balanced chemical equation.
solute The solute is the component of the solution
that is there in smallest amount.
solutionA solution is defined as a homogeneous
mixture composed of solvent and one or more
solutes.
solvation Solvation is the forming of a layer of
bound solvent molecules around a solute.
solvent The solvent is that component of a solution
that is present in largest amount.
specific heat capacity (or specific heat) (c)The
specific heat capacity is the quantity of heat
needed to raise the temperature of 1 g of the
substance by 1 K.
spectator ions Spectator ions are ions that are not
actually involved in the chemical reaction taking
place, but simply maintain electrical neutrality.
speed of light (c) The speed of light is the speed at
which all electromagnetic radiation travels in
a vacuum, 3.0 × 108 m/s.
spin quantum number (ms) The spin quantum
number indicates the direction the electron is
spinning.
standard cell potential (E°) The standard cell
potential is the potential (voltage) associated with
an electrochemical cell at standard conditions.
standard enthalpy of formationThe standard
enthalpy of formation of a compound (ΔHf°) is
the change in enthalpy when 1 mol of the com-
pound is formed from its elements and when all
substances are in their standard states.
standard molar entropies (S°) Standard molar
enthalpies of elements and compounds are the
entropies associated with 1 mole of a substance in
its standard state.
standard reduction potentialsThe standard reduc-
tion potential is the voltage associated with a half-
reaction shown in the form of reduction.
state functionA state function is a function that
doesn’t depend on the pathway, only the initial
and final states.
stoichiometryStoichiometry is the calculation of
the amount (mass, moles, particles) of one sub-
stance in the chemical reaction through the use of
another.
strong acidA strong acid is an acid that ionizes
completely in solution.
strong baseA strong base is a base that ionizes
completely in solution.
strong electrolytesStrong electrolytes completely
ionize or dissociate in solution.
structural isomers Structural isomers are
compounds that have the same molecular formula
but differ in how the atoms are attached to
each other.
sublimation Sublimation is going directly from the
solid state to the gaseous state without ever having
become a liquid.
subshellsWithin the shells, the electrons are
grouped in subshells of slightly different energies.
supersaturated solutionA supersaturated solution
has more than the maximum amount of solute
dissolved in the solvent at a given temperature.
surface tensionSurface tension is the amount
of force that is required to break through the
molecular layer at the surface of a liquid.Glossary 365