Thermodynamics Overview — AP Chemistry
1. Unit at a Glance
We build this unit from the first law of thermodynamics (energy is conserved), starting with core definitions of heat, temperature, and enthalpy, before moving to practical calculation methods for enthalpy change. You will learn to distinguish between energy-absorbing and energy-releasing processes, connect these concepts to real-world measurements, and apply multiple methods to solve for reaction enthalpy.
Common Pitfalls
Why: Sign conventions always reference the system, not the surroundings, leading to flipped signs if misassigned.
Why: Energy input is required to overcome bonding interactions, so bond breaking is always endothermic.
Why: Standard enthalpy of formation is defined per mole of compound, so moles from the balanced reaction must be accounted for.