click below
click below
Normal Size Small Size show me how
Chemistry I Chap 8
Vocab
Term | Definition |
---|---|
Conservation of Energy Law | AKA first law of Thermodynamics; energy can be neither created nor destroyed. Thus, the total energy of an isolated system is constant |
Endothermic | A reaction in which heat is absorbed and the temperature of the surroundings falls |
Energy | The capacity to do work or supply heat |
Enthalpy (H) | The quantity E + PV |
Enthalpy Change (^H) | The heat change in a reaction or process at constant pressure ^H = ^E + P^V |
Entropy (S) | The amount of molecular randomness in a system |
Exothermic | A reaction in which heat is evolved and the temperature of the surroundings rises |
First Law of Thermodynamics | The total internal energy of an isolated system is constant |
Gibbs Free-Energy Change (^G) | ^G=^H-T^S |
Heat | The energy transferred from one object to another as the result of a temperature difference between them |
Heat Capacity (C) | The amount of heat required to raise the temperature of an object or substance a given amount |
Heat of Combustion (^H'c) | The amount of energy released on burning a substance |
Heat of Reaction (^H) | The enthalpy change for a reaction ^H |
Hess's Law | The overall enthalpy change for a reaction is equal to the sum of the enthalpy changes for the individual steps in the reaction. |
Internal Energy (E) | The sum of kinetic and potential energies for each particle in a system |
Joule (J) | The SI unit of energy, equal to 1 (kg*m^2)/s^2 |
Kinetic Energy (Ek) | The energy of motion Ek=(1/2)mv^2 |
Molar Heat Capacity (Cm) | The amount of heat necessary to raise the temperature of 1 mol of a substance 1'c |
Potential Energy (Ep) | Energy that is stored, either in an object because of its position or in a molecule because of its chemical composition |
Specific Heat | The amount of heat necessary to raise the temperature of 1 gram of a substance 1'c |
Spontaneous Process | One that proceeds on its own without any continuous external influence |
Standard Enthalpy of Reaction (^H') | Enthalpy change under standard-state conditions |
Standard of Heat Formation (^H'f) | The enthalpy change ^H'f for the hypothetical formation of 1 mol of substance in its standard state form from the most stable forms of its constituent elements in their standard states |
State Function | A function or property whose value depends only on the present condition of the system, not on the path used to arrive at that condition |
Sublimination | The direct converstion of a solid to a vapor without going through a liquid state. |
Temperature | A measure of the kinetic energy of molecular motion. |
Thermochemistry | A study of the heat changes that take place during reactions. |
Thermodynamic Standard State | Conditions under which thermodynamic measurements are reported 298.15 K (25'c) 1 atm pressure for each gas 1 M concentration for solutions |
Work (w) | The distance (d) moved times the force (F) that opposes the motion W=d*F |