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AP Chem



Unit 6

6.0 Unit 6 Overview: Thermochemistry and Reaction Thermodynamics

2 min readaugust 20, 2020


Dalia Savy


Dylan Black

From the College Board

👀 Develop Your Understanding of this unit

According to the College Board, "The laws of thermodynamics describe the essential role of energy and explain and predict the direction of changes in matter🧊💧. The availability or disposition of energy plays a role in virtually all observed chemical processes. Thermodynamics provides tools for understanding this key role, particularly the conservation of energy, including energy transfer in the forms of heat and work. Chemical bonding is central🔑 to chemistry.
A key concept to know is that the breaking of a chemical bond inherently requires an energy input, and because bond formation is the reverse process, it will release energy. In subsequent units, the application of thermodynamics will determine the favorability of a reaction occurring."

🔎 Big Idea Questions

  1. Why is energy released when water becomes an ice cube?
  2. How are chemical transformations that require bonds to break and form influenced by energy?

👨‍🔬What is Unit 6 about?

Welcome to Unit 6 of AP Chemistry! This unit focuses all about the energy⚡ involved in reactions, specifically the energy of heat, also known as enthalpy🔥. We will be diving deep into how energy flows when a reaction takes place, culminating in calculations involving how heat enters or leaves a system. You'll learn how to measure heat released or absorbed from a reaction by using a calorimeter and understand how changes in heat of objects are connected to this through heat capacities.
✍️About 7-9% of the exam tests your knowledge from this unit.

📝Key Vocabulary

SystemSurroundingsEnthalpyState function
Open systemEntropyCalorimeterClosed system
EnergyExothermicHeat of formationSpecific heat
EndothermicHeat capacityLaw of conservation of energyHess's Law

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Unit 1: Atomic Structure and Properties
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