FIRST LAW OF THERMODYNAMICS

• Thermodynamics


  The study of heat energy and other types of energy, such as work, and the various ways energy is transferred within chemical systems
• First law of thermodynamics

  The total amount of energy in the universe is constant. Energy can be transferred from place to place or transformed into different forms, but it cannot be created nor destroyed. It is only conserved.
• First law of thermodynamics

  1. ΔU = Q + W

  2. The + symbol is subject to change into -, depending on the work being applied to or by a system.
• ΔU


  Total change in an internal energy of a system
• Q


  Heat exchanged between a system and its surroundings
• W


  Work done by or on the system
• Endothermic Reaction


  Formation of chemical bonds through the absorption of heat from the surroundings
• Exothermic Reaction


  Releases heat, causing temperature of the immediate surroundings to rise
• Isovolumetric


  • W=0, constant volume
• Isothermal


  • ΔU=0, constant temperature
• Adiabatic


  • Q=0, no heat transfer
• Isolated System


  • Q=0, W=0, no internal energy
• Closed System


  The cryosphere may melt and refreeze, but no new water is added to it or to the hydrosphere
• Open System


  Boiling kettle | Heat energy is transferred into the water (a process known as work), which subsequently changes its state from liquid to gas, leaving the system by escaping into the surroundings
• Energy is conserved during chemical reactions.
• Chemical bonds store potential energy.
• The first law states that energy cannot be created or destroyed, only transferred from one form to another.