SCH4U - Chemistry 12 (2024-25) - A

SCH4U-25A

3-1C: Summary

This page is part of the content downloaded from 3-1C: Summary on Monday, 3 March 2025, 9:20 AM. Note that some content and any files larger than 50 MB are not downloaded.

Description

Summary

Page content

  • All substances contain a certain amount of energy within them in the form of kinetic and potential energy
  • The law of conservation of energy states that energy cannot be created or destroyed
  • The system is the object or sample that one is investigating
  • The surroundings is everything else around the system
  • Chemists are interested in the transfer of energy that takes place between system and surroundings
  • Heat is a form of energy that can be transferred, causing temperature to rise or fall.
  • The heat content of a substance is known as its enthalpy (H)
  • The change in heat that occurs in a chemical process is known as its change in enthalpy (ΔH)
  • Endothermic reaction: when the system absorbs heat from its surroundings, its temperature increases and ΔH is positive
  • Exothermic reaction: when the system releases heat to its surroundings, its temperature decreases and ΔH is negative