Thermochemistry Flashcards
potential energy
energy stored due to an objects position relative to other objects, electric charge or internal stresses
chemical energy
energy that can be released through a chemical reaction
kinetic energy
energy associated with movement
thermal energy
energy associated with movement of particles that is responsible for its temperature
covalent bonds
bonds formed due to a shared pair of electrons
surroundings
everything around the reaction such as the reaction flask and the room (what we can typically measure)
reaction system
a mixture of reactants and products undergoing a reaction
open system
system that can exchange both energy and matter with its surroundings
closed system
system that can exchange energy but not matter with its surroundings
isolated system
system that cannot exchange energy or matter with its surroundings
temperature
a measure of thermal energy
state function
a property whose value does not depend on the path taken to reach that specific value, examples: number of atoms in a molecule in solid, liquid or gas state
heat
the amount of energy that is transferred from one system to its surroundings because of a temperature difference
work
the energy needed to move against a force.
enthalpy
the measurement of energy in a thermodynamic system
enthalpy change
the amount of heat energy transferred during a chemical reaction at constant pressure.
first law of thermodynamics
energy cannot be created or destroyed; it can only be converted from one form to another
endothermic reaction
a chemical reaction that absorbs heat due to products storing more energy than the products. This causes the temperature of the immediate surroundings to lower. Enthalpy is positive.
exothermic reaction
a chemical reaction that releases heat due to reactants storing more energy than the products. This causes the temperature of the immediate surroundings to rise. Enthalpy is negative.
bond dissociation energy
the amount of energy needed to break apart one mole of covalently bonded gases into a pair of radicals
energy profile
a theoretical representation of a chemical reaction or process as a single energetic pathway as the reactants are transformed into products.
activation energy
the amount of free energy that must be added to go from the energy level of the reactants to the energy level of the transition state.
standard enthalpy change
the enthalpy change that occurs when 1 mole of the substance is formed from its constituent elements in their standard states
specific heat capacity
the amount of heat that must be added to one gram of the substance in order to raise its temperature by 1 degree K