Prepared by Dr. A. Fried – March 15, 2014
REVIEW SHEET – EXAM 2
Types of chapter 4-related problems that are similar to problems that will appear on the exam
1. Distinguish between weak and strong electrolytes.
2. Distinguish between molecular and ionic compounds, AND be able to recognize
and write the major ionic species in an ionic compound even if it is written as if it
were a molecular compound (that is, not showing its ions or charges).
3. Distinguish between compounds that are soluble in water from those that are not
when given only their names or formulas.
4. Predict what precipitate(s) would form after two or more ionic compounds are
mixed together in water.
5. Identify or write the net ionic equation for the reaction that occurs when a weak
acid and a strong base are mixed together.
6. Write the net ionic equation for a reaction that occurs when two aqueous solutions
of ionic compounds are added together.
7. Write the oxidation number of each of the atoms in an ionic compound.
8. Deduce the total number of electrons which are transferred in a given redox
reaction.
9. Distinguish between redox and non-redox equations.
10. Identify the reducing agent in a given chemical redox equation.
11. Identify which element is reduced in a given redox equation.
12. Predict the products of a given type of reaction, such as the products of a single
replacement reaction.
13. Recognize the type of reaction represented if given the equation for it.
14. Calculate the concentration of an ion if you are given how many grams of an
ionic compound is dissolved in water to give a particular volume (mL) of the
resulting solution.
15. Calculate the concentration of an acid (or base) if you are given its molarity and
volume (mL or L), and water is added until the volume of the solution reaches a
specified volume (mL or L). Calculate the molarity of one kind of ion species in
the final solution resulting from the mixture of two solutions of two different ionic
Prepared by Dr. A. Fried – March 15, 2014
compounds of given molarity and volume. (Both compounds contain the ion in
question, such as found in AlCl3 and LiCl.)
16. Be able to solve a stoichiometry problem involving the reaction of solutions. Here
is just one example. Suppose you mix two aqueous solutions: 38.1 mL of 0.217
M Li2CO3 and 224.0 ml of Co(NO3)3. The precipitate from the resulting reaction
after mixing these two solutions is Co2(CO3)3. Let the dried precipitate have a
mass of 0.5854 g. a) What was the concentration of cobalt ions in the original
solution before it was mixed. Assume that the lab tech doing this experiment had
excellent technique and did not lose any of the precipitate that was formed. A
different question (for a different problem using the same reaction, and the
same volume and calculated molarity* of Co(NO3)3) could have been asked; for
example, How many mL of the other reactant’s solution (i.e., of 0.217 M Li2CO3),
would actually be needed to react to form the same amount of the solid product?
*I am referring to the molarity of the Co( NO3)3 solution that can be calculated
from the data from the first kind of problem (above).
17. What volume (mL) of a 0.2450 M KOH(aq) solution is required to completely
neutralize 55.25 mL of a 0.5440 M H3PO4(aq) solution? Calculate the volume
(mL) of an aqueous solution of a strong base (molarity given) that is required to
completely neutralize a given volume of a solution of a weak acid (volume and
molarity given). Be able to solve this kind of problem with mono-, di-, and triprotic
acids. {Also be able to solve other similar acid-base neutralization problems
when a strong acid is used to neutralize a weak base. Or when a strong acid is
used to neutralize a strong base. These kinds of problems would be called acidbase titration problems when the objective is to determine the molarity of an acid
or a base.}
18. Be able to solve a variety of problems involving solution stoichiometry. Here is
another one: Sodium metal reacts with water to yield hydrogen gas and aqueous
sodium hydroxide. What is the final concentration of hydroxide ions when 17.50 g
of sodium metal is dropped into 821 mL of water? This problem’s solution
depends on knowledge of stoichiometry as presented in Chapters 3 and 4; you
have to know about molarity, moles, and writing and balancing chemical
equations.