5.2 Calorimetry & Enthalpy Flashcards
Calorimetry
The process of measuring energy changes during a
physical or chemical change.
Calorimeter
A device used to measure energy changes. (It must contain a well-insulated reaction chamber at CONSTANT PRESSURE, a tight-fitting cover with insulated holes for a thermometer, and a stirrer. )
Specific heat capacity (c)
The quantity of thermal energy required to raise the temperature of 1g of a substance by 1 degree celsius; J/g degrees C
Enthalpy
The total amount of thermal energy in a substance
Enthalpy change
The energy released to or absorbed from the surrounding during a chemical change
Molar enthalpy change
The enthalpy change associated w a physical, chemical, nuclear change involving 1 mol of a substance
Potential energy diagram
A graphical rep. of the energy transferred during a physical or chemical change
The total amount of thermal energy absorbed
or released by a chemical system is given by
the symbol q. It depends on three factors:
The mass of the substance
The specific heat capacity of the substance
The temperature change experienced by the
substance as it warms or cools.
Energy cannot be created or destroyed… so
the total thermal energy of the system and its
surroundings remain _______.
constant
For molar enthalpy change of formation of a
product, the coefficient in the equation must
always be ___.
one
For an ________ reaction, the reactants have more potential energy than the products.
exothermic
Exothermic
In a thermochemical equation, the energy term is on the _____ side, showing that energy is _______.
product; released
For an ___________ reaction, the products will have more potential energy than the reactants.
endothermic
Endothermic
In a thermochemical equation, the energy term is on the _______ side, showing that energy is _______.
reactant; absorbed
