Ch. 6 Thermochemistry
1383345407 | energy | the capacity to do work or to cause heat to flow | 1 | |
1383345408 | law of conservation of energy | energy can be converted from one form to another but can be neither created nor destroyed | 2 | |
1383345409 | potential energy | energy due to position or composition | 3 | |
1383345410 | kinetic energy | (1/2mv2) energy due to the motion of an object; dependent on the mass of the object and the square of its velocity | 4 | |
1383345411 | heat | energy transferred between two objects due to a temperature difference between them | 5 | |
1383345412 | work | force acting over a distance | 6 | |
1383345413 | pathway | the way in which energy transfer is divided between work and heat | 7 | |
1383345414 | state function (property) | a property that is independent of the pathway | 8 | |
1383345415 | system (thermodynamic) | that part of the universe on which attention is to be focused | 9 | |
1383345416 | surroundings | everything in the universe surrounding a thermodynamic system | 10 | |
1383345418 | exothermic | refers to a reaction where energy (as heat) flows out of the system | 11 | |
1383345420 | endothermic | refers to a reaction where energy (as heat) flows into the system | 12 | |
1383345422 | thermodynamics | the study of energy and its interconversions | 13 | |
1383345423 | first law of thermodynamics | the energy of the universe is constant; same as the law of conservation of energy | 14 | |
1383345424 | internal energy | a property of a system that can be changed by a flow of work, heat or both; delta E = q + w, where delta E is the change in the internal energy of the system, q is heat, and w is work | 15 | |
1383345425 | enthalpy | a property of a system equal to E + PV, where E is the internal energy of the system, P is the pressure of the system, and V is the volume of the system; at constant pressure the change in enthalpy equals the energy flow as heat | 16 | |
1383345426 | calorimeter | device used experimentally to determine the heat associated with a chemical reaction | 17 | |
1383345427 | calorimetry | the science of measuring heat flow | 18 | |
1383345428 | heat capacity | the amount of energy required to raise the temperature of an object by one degree Celsius | 19 | |
1383345429 | specific heat capacity | the energy required to raise the temperature of one gram of a substance by one degree Celsius | 20 | |
1383345431 | molar heat capacity | the energy required to raise the temperature of one mole of a substance by one degree Celsius | 21 | |
1383345432 | constant-pressure calorimetry | the measurement of heat using a simple calorimeter to determine the changes in enthalpy (heats of reaction) for reactions occurring in solution; the pressure (atmospheric pressure) remains constant during the process | 22 | |
1383345433 | constant-volume calorimetry | the measurement of heat at a constant volume to find the change in internal energy of the system; requires the use of a "bomb" calorimeter | 23 | |
1383345436 | Hess's law | in going from a particular set of reactants to a particular set of products, the enthalpy change is the same whether the reaction takes place in one step or in a series of steps; in summary, enthalpy is a state function | 24 | |
1383345437 | standard enthalpy of formation | the enthalpy change that accompanies the formation of one mole of a compound at 25 degree Celsius from its elements, with all substances in their standard states at that temperature | 25 | |
1383345438 | standard state | a reference state for a specific substance defined according to set of conventional definitions | 26 | |
1383345439 | fossil fuels | coal, petroleum, or natural gas; consists of carbon-based molecules derived from decomposition of once-living organisms | 27 | |
1383345440 | petroleum | a thick, dark liquid composed mostly of compounds called hydrocarbons that contain carbon and hydrogen | 28 | |
1383345441 | natural gas | usually associated with petroleum deposits, consists mostly of methane, but it also contains significant amounts of ethane, propane, and butane | 29 | |
1383345442 | coal | formed from the remains of plants that were buried and subjected to high pressure and heat over long periods of time | 30 | |
1383345443 | greenhouse effect | a warming effect exerted by the earth's atmosphere (particularly CO2 and H2O) due to thermal energy retained by absorption of infrared radiation | 31 | |
1383345444 | syngas | synthetic gas, a mixture of carbon monoxide and hydrogen, obtained by coal gasification | 32 |