Writing and Predicting Chemical Reactions
Question 1 of Section II (also known as Part A) of the AP chemistry exam is alwaysa question
on writing reactions. The directions for this question follow.
- You may NOT use a calculator for this section of the exam. You will be given 10 minutes
to answer FIVE of the eight options in this part. (Answers to more than five options will
not be scored.)
Give the formulas to show the reactants and the products for FIVE of the following chemical
reactions. Each of the reactions occurs in aqueous solution unless otherwise indicated.
Represent substances in solution as ions if the substance is extensively ionized. Omit formulas
for any ions or molecules that are unchanged by the reaction. In all cases a reaction occurs. You
need not balance.
Example:A strip of magnesium is added to a solution of silver nitrate.
Mg + Ag+→Mg2++ AgThe question is scored according to the following guide:
- Each of the five reactions you choose is worth a maximum of 3 points — 15 points in all.
- One point is given if the reactants are correct.
- Two points are given if the products are correct.
- If the equation is correct but the charge on the ions is incorrect, 1 point is deducted.
- Part A represents 15% of your score for Section II.
In order to do well on this question, you must know the solubility rules! See page 116 of this
book. Also, in the sections that follow, I have tried to give you generalrules for predicting the
products when the reactants are given. These guidelines will not work for 100% of the ques-
tions on the AP exam, but they should get you through at least four or five of the eight you are
presented with — and that’s all you need.