Thermochemistry Vocab

energy

energy

capacity to do work or produce heat; heat (q) + work (w)

work

transfer of energy as force is applied to displace an object (1 L*atm = 1 J)

kinetic energy

energy an object has bc of its motion; KE = 1/2mv²

potential energy

energy that is stored and can be released as work or heat; PE = mgh

chemical potential energy

energy stored in bonds, can be released through a chemical reaction

heat

total energy of a specific sample, extensive

temperature

average KE of the particles in a sample, intensive

calorie

energy needed to raise 1g of water by 1 C

kilocalorie / Calorie

energy needed to raise 1kg of water by 1 C

system

identifiable collection of objects

surroundings

everything else that is not part of the system

endothermic reaction

chemical reactions that absorb heat from surroundings

exothermic reaction

chemical reactions that release heat into surroundings

activation energy

minimum energy the reactants need to begin a chemical reaction

catalyst

substance that lowers the activation energy, not consumed during the chemical reaction

heat of fusion

energy needed to switch between solid and liquid

heat of vaporization

energy needed to switch between liquid and gas

state function

functions whose values depend only on the current state of the system and not how the system arrived at that state (exs. pressure, volume, temperature)

internal energy

all the energy within a specific system (KE + PE)

enthalpy

internal/ total energy in a system, total heat

calorimetry

process of measuring heat released/ absorbed in a chemical reaction

specific heat capacity

amount of heat needed to raise 1g of substance by 1 C

standard enthalpy of formation

enthalpy change when 1 mole of pure substance is formed from its elements

standard state

reference state for thermodynamic characteristics; 1 atm, 25 C