chapter 17 Flashcards
Heat
Energy that transfers from one object to another because of a temp. difference between them
exothermic process
a process that loses heat to the surroundings
heat capacity
the amount of heat required to change the temp of an object by exactly 1 degree C
system
the part of the universe being studied
endothermic process
a process that loses heat to its surroundings
enthalpy (H)
the amount of heat that a system has at a constant pressure
heat of combustion
the heat of reaction for the complete burning of 1 mole of a substance
thermochemical equation
includes the enthalpy change
calorimetry
accurate and precise measurement of heat changes for chemical and physical processes
bomb calorimeter
insulated device containing sealed vessel that is used to measure the heat released during a combustion reaction
molar heat of fusion
heat absorbed by 1 mole of a substance in melting from a solid to a liquid
molar heat of solidification
heat lost when 1 mole of a liquid solidifies at a constant temperature
molar heat of vaporization
amount of heat necessary to vaporize 1 mole of a liquid
∆Hvap
-∆Hcond
molar heat of solution
the heat change caused by dissolution of 1 mole of solution
standard heat of formation
the change in enthalpy that accompanies the formation of 1 mole of a compound from its elements
Hess’s law of heat summation
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 series of steps
ΔH f
symbol for the standard heat of formation
zero
ΔH f of Cl2 g)
during which change is energy absorbed
the melting of ice
