chem whatdriveschemicalreactions

Reactivity 1.1.1 - chemical reactions involve a transfer of energy between the system and the surroundings, while total energy is conserved
  • energy is a measure of the ability to do work, to move an object against an opposing force

Important

  • heat is a form of energy transfer that occurs as a result of a temperature difference, a process of energy transfer
  • temperature, rather, is a measure of the average kinetic energy of the particles, which is a property of the system.

the system is the area of interest, and the surroundings is the rest of the universe

  • an open system allows energy and matter to be exchanged with the surroundings
  • in a closed system, energy can be exchanged with the surroundings, but the matter cannot. the total energy does not change during the process, however.
  • an isolated system cannot exchange matter or energy with the surroundings

the chemical potential energy of a system is called enthalpy. when heat is added to a system from the surroundings, the enthalpy of the system increases. when the system gives out heat, its enthalpy decreases. changes in enthalpy are denoted by .