thermochemistry definitions Flashcards
energy
measurement of the ability to do work
work
occur when a force is applied to an object and the object moves in the direction of the force
kinetic energy
energy associated with motion
potential energy
stored energy
physical change
change in form/state
chemical change
rearrangement of atoms
nuclear change
formation of new atoms
law of thermodynamics
energy can change forms, but is neither created nor detroyed
thermal energy
total kinetic energy of all entities in a substance (measured in Joules)
temperature
quantity expressed as T, is the measure of average kinetic energy of the entities in a substance (measured in celsius)
heat
form of energy that describes the amount of thermal energy flown/transferred between substances, systems, or surroundings due to temp. difference
chemical system
set of reactants and products undergoing energy change
surroundings
all of the matter around the system that is capable of absorbing or releasing thermal energy
open
energy and matter can move in and out of the system
closed
only energy can move in or out of the system
isolated
neither energy nor matter can move in or out of the system
exothermic
energy is relaeased from the system to the surroundings
inc. temp. of surr
endothermic
energy is absorbed by the system from the surroundings
dec. temp. of surr.
calorimetry
experimental technique to measure heat of energy changes in a chemical system
specific heat capacity
the quantity of heat required to raise the temperature of 1g of mass or 1 degree of 1K of a substance
negative q
exothermic
positive q
endothermic
bond dissociation energy
average quantity of energy required to break a chemical bond
what are the factors that affect the bond energy of a chemical bond
bond length, bond type, electronegativity difference between the 2 atoms
