chemical thermodynamics Flashcards
(19 cards)
kinetic energy
energy associated with motion
potential energy
energy associated with the position of an object and the forces upon it
system
portion being studied
internal energy
(E) the sum of all possible forms of energy of the ions,atoms,and molecules in the system
first law of thermodynamics
the energy lost(or gained) by the system = the energy gained(or lost) by the surroundings
heat
(Q) the transfer of energy as a result in temperature change
work
(W) the transfer of energy thorough a force applied across a distance
the change in internal energy for a closed system equation
ΔΕ= Q+W
the change in internal energy for any system equation
ΔΕ=E{final}-E{initial}
enthalpy
(H) the initial energy + the product pressure and volume
enthalpy equation
ΔH= ΔΕ+ PΔV
endothermic
the products are colder than the reactants because energy has been absorbed (ΔH is positive)
exothermic
the products are warmer than the reactants because energy has been released( ΔH is negative)
enthalpy reactions
total energy released or absorbed between the start of a certian reaction and its end
thermochemical equations
chemical equations written to show the change in enthalpy
specific heat
(c)the heat required to cause a unit rise in the temperature of a unit mass
C=Q/mΔT
enthalpy of fusion
the energy per weight mass required to melt a substance at its melting point Δ(sub fus)H
enthalpy of vaporization
the energy required to vaporize a substance at its boiling point
vapor pressure
the partial pressure at which the liquid and vapor phases are in equilibrium
