Chapter 6 Vocabulary Flashcards
Energy
Anything that has the capacity to do work.
Work
A force acting over a distance
Energy = Work = Force x Distance
Heat
The flow of energy caused by a difference in temperature
Kinetic energy
Energy of motion or energy that is being transferred
Thermal energy
The energy associated with temperature
Potential energy
Energy that is stored in an object, or energy associated with the composition and position of the object. Energy stored in the structure of a compound is potential.
Forms of Energy
Electrical: Kinetic energy associated with the flow of electrical charge.
Heat of thermal energy: Kinetic energy associated with molecular motion.
Light or radiant energy: Kinetic energy associated with energy transitions in an atom.
Nuclear: Potential energy in the nucleus of atoms.
Chemical: Potential energy due to the structure of the atoms, the atoms’ positions relative to each other in the molecule, or the molecules, relative positions in the structure.
Law of Conservation of Energy
States that energy cannot be created nor destroyed.
System
The material or process within which we are studying the energy changes within.
Surroundings
Everything else with which the system can exchange energy with.
Joule (J)
The amount of energy needed to move 1-kg mass a distance of 1 meter.
1 J = 1 Nm = 1 kgm^2/s^2
Chemical energy
The energy associated with the relative positions of electrons and nuclei in atoms and molecules.
calorie (cal)
The amount of energy needed to raise the temperature of one gram of water by 1 degree Celsius.
Thermodynamics
The study of energy and its interconversions.
The First Law of Thermodynamics
The total energy of the universe is constant.
Internal Energy (E)
The sum of the kinetic and potential energies of all of the particles that compose the system.
State function
A mathematical function whose result only depends on the initial and final conditions, not on the process used.
Heat
The exchange of thermal energy between the system and the surroundings. Heat exchange occurs when the system and surroundings have a difference in temperature.
Temperature
The measure of the amount of thermal energy within a sample of matter.
Thermal equilibrium
Heat flows from matter with high temperature to matter with low temperature until both objects reach the same temperature.
Heat Capacity (C)
The quantity of heat required to change its temperature by 1 degree celsius.
Specific Heat Capacity
The amount of heat energy required to raise the temperature of one gram of a substance by 1 degree celsius.
Molar Heat Capacity
The amount of heat energy required to raise the temperature of one mole of a substance by 1 degree celsius.
Enthalpy (H)
The sume of the internal energy of the system and the product of pressure and volume.
Enthalpy change
The heat evolved in a reaction at constant pressure.
Exothermic Reactions
Reactions that release heat
Endothermic Reactions
Reactions that absorb heat
Standard State
The state of a material at a defined set of conditions.
Pure gas at exactly 1 atm pressure
Pure solid or liquid in its most stable form at exactly 1 atm pressure and temperature of interest.
Substance in a solution with concentration 1 M.
Standard enthalpy change, ΔH
The enthalpy change when all reactants and products are in their standard states
Standard enthalpy of formation
The enthalpy change for the reaction forming 1 mole of a pure compound from its constituent elements.
