Third Quarter Review Sheet
REACTIONS:
1. Define and explain how precipitates are formed?
Identify the type of reaction for 2-6
2. C3H5(NO3)3
heat

 CO2 + N2 + H2O + O2
3. Zn + 2HCl  ZnCl2 + H2
4. Pb(NO3)3 + K2CrO4  PbCrO4 + KNO3
5. 2C6H6 + 15O2  12CO2 + 6H2O
6. 3H2 + N2  2NH3
Balance the equations for questions 7 through 11
7. HgO + Cl2  HgCl + O2
8. C2H4 + O2  CO2 + H2O
9. Ca(OH)2 + HNO3  Ca(NO3)2 + H2O
10. P4 + O2  P4O10
11. FeS2 + O2  Fe2O3 + SO2
12. Which of the following reaction will take place?
a. Mg + LiOH 
b. Na + Al2(SO3)3 
c. Hg + CuS 
d. None of the above
13. What happens to Na2SO4 when mixed into water?
14. Which of the following will not break up upon being mixed into water?
a. NaCl
b. NO2
c. Mg(NO3)2
d. FeCl3
15. Which of the following will break up upon being mixed in water?
a. CaCO3
b. AgCl
c. Ba(OH)2
d. MgO
16. Write the net ionic equation for the following pair of reactants?
AgNO3 + NaOH
17. What are the spectator ions in the previous reaction?
18. Write the net ionic equation for the following pair of reactants?
Fe(NO3)2 (aq)+ MgS (aq)
19. Suppose we were doing an experiment in which we were trying to predict precipitates formed
in double replacement reactions. We find that many of these reactions yield precipitates yet one
of them, between NaCl and Mg(NO3)2, does not. What is the correct explanation for this?
20. The following data table was generated by a student by mixing two ionic compounds together
and then writing down the results. The student’s data is listed below:
Na2SO4
MgCl2
Ba(NO3)2
White precipitate
No precipitate
NaOH
No precipitate
White precipitate
Based on the student’s data above, which of the following substances is one of the
precipitates formed in the lab above?
a.
NaCl
b. Mg(NO3)2
c. Ba(OH)2
d. BaSO4
21. In redox reactions oxidation is always coupled with what?
22. Define the terms oxidation and reduction.
23. What three substances can be added freely to a redox reaction occurring in an acidic solution
in order to balance a half reaction?
24. What is meant by “half reaction” in reference to a redox reaction?
25. In a redox reaction the number of electrons in the oxidation half reaction must equal
26. What is the oxidation number of “Cr” in MgCr2O7?
27. What is the oxidation number of “P” in PO43-?
28. Identify what is oxidized in the following reaction.
3H2S + 2HNO3  3S + 2NO + 4H2O
29. Identify what is reduced in the reaction from the previous problem.
30. Identify the oxidizing agent in the following reaction.
KMnO4 + HCl  MnCl2 + Cl2 + H2O + KCl
a. MnCl2
b. KCl
c. KMnO4
d. HCl
31. Balance the following 1/2 reaction.
MnO41-  Mn2+
32. What half reaction is shown above?
33. Which of the following correctly balances the following 1/2 reaction?
Cl1-  Cl2
34. What half reaction is shown above?
35. What is the net ionic equation for the following
Pb(ClO3)2 (aq)+ NaI (aq) 
MOLE:
1. Avagadro’s number tells us what?
2. Define empirical formula.
3. How many atoms are in a sample of an element whose mass in grams is numerically equal
to its atomic mass?
4. What kind of substance is represented by a formula unit?
5. The molar mass of individual elements is generally expressed in which unit?
6. How many ions of Cu+2 are there in one formula unit of Cu3(PO3)2?
7. The mass of each element in a compound compared to the entire mass of the compound is
called what?
8. The percent composition of magnesium chloride, MgCl2, is?
9. What is the empirical formula for a compound whose molecular formula is C2Cl6?
10. What is the only possible molecular formula, from the choices below, for a compound whose
empirical formula is CH?
a. C2H
c. CH2
b. C2H2
d. need more info
11. If the empirical formula of a compound is found to be CH2, which of the following values are
possible molecular molar masses?
a. 21.04
b. 46.76
c. 12.01
d. 70.15
12. Which of the following correctly describes how to convert 250g of CaOH into formula units?
a. Convert 250g of CaOH into moles by dividing by the molar mass and then divide that
by 6.02x1023.
b. Convert 250g of CaOH into moles by dividing by the molar mass and then multiply
that by 6.02x1023.
c.
Convert 250g of CaOH into moles by dividing by the molar mass and then divide that
by 6.02x1023. Once you have that number multiply by 3.
d. Convert 250g of CaOH into moles by dividing by the molar mass and then multiply
that by 6.02x1023. Once you have that number multiply by 3.
13. Calculate the molar mass of Li(OH)2.
14. How many F- ions are present in 2.50 moles of BaF2?
15. If you have 2.87x1024 formula units of MgCl2, how many moles do you have?
16. What is the volume of 16g of O2?
17. If you have 348L of H2O vapor, how many moles do you have?
18. If you have 26.4g of gold, how much of a mole do you have?
19. What is the empirical formula of a compound that is 46.62% Na, 20.95% P, and 32.43% O?
20. If a compound has an empirical of CH2O, and a molecular mass of 120g, what is the
molecular formula?
21. What is the representative particle for P4O10?
22. What is the representative particle for BaCl2?
23. How many grams of Mg are present in 150.0g of Mg3(PO4)2?
24. Define the term mole with respect to mass, volume, and representative particles.