Chemistry 12 - Thermochemistry

exam review of terms from thermochem

calorimetry

process of measuring thermal energy change within physical or chemical changes

heat

the transfer of thermal energy from a warm object to a cooler object

specific heat capacity

the amount of thermal energy needed in order to raise the temperature of 1g of a substance by 1 degree C

chemical change

one chemical substance transforms into one or more different substances

Hess’ Law

the total enthalpy change for a chemical reaction is the same, regardless of number of steps, as long as initial reactants and final products are the same

surroundings

matter not defined as the system

chemical system

group of reactants and products being studied

molar enthalpy

enthalpy change in chemical, physical, oe nuclear change involving 1mol of a substance

temperature

measure of the average kinetic energy in a substance

endothermic

absorbing energy from surroundings

open system

both matter and energy are free to enter and leave system

thermal energy

total quantity of kinetic and potential energy in a substance

enthalpy

total amount of thermal energy in a substance

physical change

alters a substance’s form but not the chemical composition

exothermic

releasing energy to surroundings

potential energy diagram

graphical representation of energy transferred during a physical/chemical change