Term | Definition |
intermolecular forces | forces of attraction between molecules that affect how a substance behaves(weaker than ionic and covalent bonds) |
enthalpy | the heat content of a system at constant pressure |
entropy | a measure of the disorder in a system |
kinetic energy | the energy an object has because of its motion |
temperature | a measure of the average kinetic energy of the particles in a substance |
spontaneous reaction | a reaction will likely occur on its own if it can achieve a decrease in energy and and increase in disorder |
exothermic | a reaction that releases heat into the surroundings |
endothermic | a reaction that absorbs heat from the surroundings |
dipole-dipole force | the attraction of the positive end of a polar molecule to the negative end of a neighboring polar molecule |
solid | particles in the sample have an orderly arrangement and move only in place |
liquid | particles in the sample are loosely packed together and can move past each other |
gas | particles in the sample are separated from each other by a great amount of open space |
melting | the process by which a solid becomes a liquid |
enthalpy (heat) of fusion | the amount of energy needed to melt a substance |
enthalpy (heat) of vaporization | the amount of energy needed to evaporate a substance |
freezing | the process by which a liquid becomes a solid |
vaporization/evaporation | the process by which a liquid becomes a gas |
condensation | the process by which a gas becomes a liquid |
sublimation | the process by which a solid becomes a gas |
deposition | the process by which a gas becomes a solid |
heat capacity | the amount of heat needed to increase the temperature of a substance one degree Celsius |
specific heat | the amount of heat needed to increase the temperature of a one gram of a substance one degree Celsius |
heat of reaction | the change in enthalpy for the reaction as written (delta H) |
dipole | a molecule that has a region of negative charge and a region of positive charge |
dispersion forces | attraction between non polar molecules caused by the movement of electrons creating momentary dipoles |
hydrogen bonds | the strongest intermolecular force in which a hydrogen atom is attracted to a fluorine, oxygen, or nitrogen atom |
surface tension | the tendency of a surface of a liquid to resist an external force |
viscosity | resistance to flow |
adhesion | when different molecules are attracted to one another due to intermolecular forces |
cohesion | when molecules of the same type are attracted to one another due to intermolecular forces |