kinetic molecular theory
the theory that all matter is composed of particles (atoms and molecules) moving constantly in random directions
smallest arrangement of atoms in a crystal lattice that has the same symmetry as the whole crystal
solid whose atoms ions and molecules are arranged in an orderly geometric structure
energy required to overcome the attrations holding the surface particles in the interiro thus increasing the surface are of the liquid
the temperature at which the forces holding a crystal lattice together are broken and it becomes a liquid
when watervaport molecules lose energy, its velocity decreases making them more likely to form hydrogen bonds with another water molecule
process by which a ubstance changes froma gas or vaport to a solid w/o first becoming a liquid
equal volumes of fases at the same temp and pressure contain equal numbers of particles
boiling point elevation
the difference in temperature between the boiling point of a solution and the boiling point of the pure solvent
freezing point depression
the difference in temperature between the freezing point of a solution and the freezing point of the pure solvent
law of conservation of energy
the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes
the overall enthalpy change in a reaction is equal to the sum of enthalpy changes for the individual steps in the process
standard enthalpy heat of formation
The change in enthalpy that accompanies the formation of one mole of a compound in its standard state from its constituent elements in their standard states.
a balanced equation that includes the physical stateof all reactants and products and the enegry change
enthalpy of combustion of a substance
the enthalpy change for the complete burning of one mole of the substance
molar enthalpy of vaporization
the amount of energy as heat that is needed to vaporize one mole of liquid at the liquid's boiling point
molar enthalpy of fusion
the amount of energy as heat required to chang 1 mol of a substance from solid to liquid at constant temperature and pressure
molar enthalpy of condensation
= the molar enthalpy (heat) of vaporization (same numerical value) but opposite signs!
molar enthalpy of solidification
= molar enthalpy (heat) of fusion (same numerical value) but opposite signs!
in a reversible chemical reaction, the point at which the rate of the forward reaction equals the rate of the reverse reaction.
law of chemical equilibrium
states that at a given temperature, a chemical system may reach a state in which a particular ratio of reactant and product concentrations has a constant value
the ratio of product concentrations to the reactant concentrations at equilibrium, with each concentration raised to the power equal to the number of moles of that substance in a balanced chemical equation; Keq.
le chateliers principle
States that if a stress is applied to a system at equilibrium, the system shifts in the direction that relieves the stress.
any kind of change in a system at equilibrium, the system shifts in the direction that relieves the stress
The relationship between the pressure and volume of a gas at constant temperture; when volume increase, pressure decreases.
shifts to right
adda reactant, remove a product lower the tempreature in an exothermic reaction, raise the temperature in an endothermic reaction
shifts to the left
remove a rectant remove a product raise the temperature in an endothermic reaction, lower the temperature in an exothermic reaction
An acid is a substance that contains hydrogen and ionizes to produce hydrogen ions in aqueous solution; A base is a substance that contains a hydroxide group and dissociates to produce a hydroxide ion in aqueous solution
a chemical reaction in which an acid and a base interact with the formation of a salt
a measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete
The point during a titration when the number of H+ ions and OH- ions are equal. This is at the middle of the steepest part of the titration curve.
A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.
a substance capable of bringing about the reduction of another substance as it itself is oxidized
positive or negative number that indicates how many electrons an atom has gained, lost, or shared to become stable
an apparatus that uses a redox reaction to produce electrical energy or uses electrical energy to cause a chemical reaction
an electrically conductive material, usually a metallic strip that conducts electrons into and out of the solution in a half cell
a measure of the tendency of a given half-reaction to occur as a reduction in an electrochemical cell
A tube that allows the slow transfer of ions and maintains the neutrality of the electrolyte solutions.
a cell in which the flow of electrical energy from an external source causes a redox reaction to occur