Thermodynamics Vocab Flashcards
Calorimetry
the science of measuring heat flow
Endothermic
refers to a reaction where energy (as heat) flows into the system
Energy
the capacity to do work or to cause heat flow
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
Exothermic
refers to a reaction where energy (as heat) flows out of the system (6.1)
Fossil fuel
coal, petroleum, or natural gas; consists of carbon based molecules derived from
decomposition of once living organisms
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
Heat
energy transferred between two objects due to a temperature difference between them
Heat capacity
the amount of energy required to raise the temperature of an object by one degree Celsius (6.2)
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
Internal energy
a property of a system that can be changed by a flow of work, heat, or both; E = q + w, where, E is the change in the internal energy of the system, q is heat, and w is work
Kinetic energy
½mv2 energy due to the motion of an object; dependent on the mass of the object and the square of its velocity
Law of Conservation of Energy
energy can be converted from one form to another but cannot be
created nor destroyed
Molar heat capacity
the energy required to raise the temperature of one mole of a substance by one degree Celsius
Potential energy
energy due to position or composition
Specific heat capacity
the energy required to raise the temperature of one gram of a substance by one degree Celsius
Standard Enthalpy of Formation
the enthalpy change that accompanies the formation of one mole of a compound at 25°C from its elements, with all substances in their standard states at that temperature.
Standard State
Standard state reference for a specific substance defined according to a set of conventional definitions. This is the most stable variable of an element
State Function (property)
a property that is independent of the pathway
Surroundings
everything in the universe surrounding a thermodynamic system
Synthetic Gas
a mixture of carbon monoxide and hydrogen, obtained by coal gasification
System (thermodynamics)
that part of the universe on which attention is to be focused
Thermodynamics
the study of energy and its interconversions
Work
force acting over a distance
First Law of thermodynamics
the energy of the universe is constant; same as the law of conservation
of a liquid
Friction Heating
Energy transferred to a surface through movement, heating it slightly
