AP CHEMISTRY
WEEK 4
Study Guide
, AP CHEMISTRY
WEEK 4 STUDY GUIDE
Message to Lumist AP Learners
Hi AP Campers! Welcome to week four of AP Chemistry. This week’s unit is Chemical
Reactions, which covers 7-9% of the AP exam.
We will begin our discussion with different types of reactions such as displacement
reactions and combustion reactions. Next, we will look at chemical and physical
changes. In this chapter, you will also learn to write net ionic equations. In chapter 1 we
looked at the mole concept. This week we will revisit stoichiometry and the concept of
a limiting reagent. One new concept for some students may be titrations. This is an
experimental technique conducted in chemistry labs to find the concentration of a
solution. This chapter will also introduce two important concepts: Brønsted-Lowry
acids/bases and redox reactions.
Content covered this week will come back in the upcoming weeks. For example, acid-
base reactions will be covered in more detail when we study the acids and bases unit.
In the last unit of AP chemistry, we will learn about electrochemical cells which involve
redox reactions. A solid grasp of this week’s concepts will set you up for success in later
chapters.
This guide includes tips to help you avoid common misunderstandings and remember
key concepts. The end of this guide has a problem set with questions you can expect on
the exam. There is also a bonus question for students who want extra practice and a bit
of a challenge.
Good luck!
02
, AP CHEMISTRY
WEEK 4 STUDY GUIDE
Chapter Overview: Topics & Concepts
4.1 Introduction to Chemical Reactions
Synthesis Reactions
When two compounds react to form another compound
Decompositions Reactions
These are the complete opposite of synthesis reactions. One compound breaks
down to its elements.
𝑒𝑥 𝑁𝑎𝐶𝑙 → 𝑁𝑎! + 𝐶𝑙 "
Single Displacement/Replacement Reactions
When one element replaces another in a molecular compound
𝑒𝑥. 𝑍𝑛 + 𝐶𝑢𝑆𝑂# → 𝐶𝑢 + 𝑍𝑛𝑆𝑂#
Single displacement reactions only take place when the atom replacing the other is
more reaction. For example, in the equation above, the reaction will only take
place if C is more reactive than A
Reactivity or activity series: a list that puts metals and non-metals in order from
most to least reactive. *Use this to determine if a single displacement rxn will take
place*
Non-metals:
Metals:
𝐾 > 𝑁𝑎 > 𝐶𝑎 > 𝑀𝑔 > 𝐴𝑙 > 𝐶 > 𝑍𝑛 > 𝐹𝑒 > 𝑁𝐻# +> 𝐻 > 𝐶𝑢 > 𝐴𝑔 > 𝐴𝑢
Most Reactive Least Reactive
03
WEEK 4
Study Guide
, AP CHEMISTRY
WEEK 4 STUDY GUIDE
Message to Lumist AP Learners
Hi AP Campers! Welcome to week four of AP Chemistry. This week’s unit is Chemical
Reactions, which covers 7-9% of the AP exam.
We will begin our discussion with different types of reactions such as displacement
reactions and combustion reactions. Next, we will look at chemical and physical
changes. In this chapter, you will also learn to write net ionic equations. In chapter 1 we
looked at the mole concept. This week we will revisit stoichiometry and the concept of
a limiting reagent. One new concept for some students may be titrations. This is an
experimental technique conducted in chemistry labs to find the concentration of a
solution. This chapter will also introduce two important concepts: Brønsted-Lowry
acids/bases and redox reactions.
Content covered this week will come back in the upcoming weeks. For example, acid-
base reactions will be covered in more detail when we study the acids and bases unit.
In the last unit of AP chemistry, we will learn about electrochemical cells which involve
redox reactions. A solid grasp of this week’s concepts will set you up for success in later
chapters.
This guide includes tips to help you avoid common misunderstandings and remember
key concepts. The end of this guide has a problem set with questions you can expect on
the exam. There is also a bonus question for students who want extra practice and a bit
of a challenge.
Good luck!
02
, AP CHEMISTRY
WEEK 4 STUDY GUIDE
Chapter Overview: Topics & Concepts
4.1 Introduction to Chemical Reactions
Synthesis Reactions
When two compounds react to form another compound
Decompositions Reactions
These are the complete opposite of synthesis reactions. One compound breaks
down to its elements.
𝑒𝑥 𝑁𝑎𝐶𝑙 → 𝑁𝑎! + 𝐶𝑙 "
Single Displacement/Replacement Reactions
When one element replaces another in a molecular compound
𝑒𝑥. 𝑍𝑛 + 𝐶𝑢𝑆𝑂# → 𝐶𝑢 + 𝑍𝑛𝑆𝑂#
Single displacement reactions only take place when the atom replacing the other is
more reaction. For example, in the equation above, the reaction will only take
place if C is more reactive than A
Reactivity or activity series: a list that puts metals and non-metals in order from
most to least reactive. *Use this to determine if a single displacement rxn will take
place*
Non-metals:
Metals:
𝐾 > 𝑁𝑎 > 𝐶𝑎 > 𝑀𝑔 > 𝐴𝑙 > 𝐶 > 𝑍𝑛 > 𝐹𝑒 > 𝑁𝐻# +> 𝐻 > 𝐶𝑢 > 𝐴𝑔 > 𝐴𝑢
Most Reactive Least Reactive
03
