Instructions:  This review is comprehensive over the first three units of Chm 203 only.  The actual final will be comprehensive over the entire semester.

IMPORTANT NOTE: The actual final is in a multiple choice format.

 I have selected what I feel are the biggest ideas from this semester.  These are listed below like learning objectives.  After each objective I have included a few problems for you to try.  Be sure to see me to resolve any trouble you are having with these concepts!

1.  Be able to do unit analysis problems that include metric to metric and metric to English conversions.  The metric to English conversion factors would be given.
 

1-1.  If gasoline costs 42.6 cents/liter, calculate the price per gallon. [4 quart = 1 gallon; 1 L = 1.06 qt]

1-2.  How many cm3 are present in 1.23 quart? [1.06 qt = 1 L]

1-3.  A substance has a density of 3.17 g/cm³.  What is the volume of 12.2 g of this substance?

1-4.  An order for medication reads "give 1.5 mg per kilogram of body weight."  How much medication should be given to a patient weighing 219 lbs?  [1 lb = 454 g]

1-5.  An observer measured the height of each of the five Chm 203 faculty.  The values were 6'4", 6'2", 5'10", 5'5", and 5'8".  What is our total combined height in meters? [12 inches = 1 ft; 2.54 cm = 1 inch]

2.  Review significant figures and the rules for multipying/dividing and adding/subtracting.
 

2-1.  What is the result of 2.29 x (3.0 + 8.116) to the proper number of significant figures?

2-2.  How many significant figures are in the value 6.070 x 10^-6 g?

2-3.  In the problem (4.81)(3.8410)/(4.040), what is the correct number of significant figures?

2-4.  In the sum 3.05 + 31.10274, what is the number of significant figures in the answer?

2-5.  What is the correct answer for this calculation: 199.4/2.00000 + 4?

3.  Be able to calculate how many protons, neutrons and electrons are in a formula such as: ¹⁷O^-2.
 

3-1.  How many protons neutrons and electrons are in ⁵⁶Co³⁺?

3-2.  How many protons neutrons and electrons are in ³⁷Cl^-?

3-3.  How many protons neutrons and electrons are in ²³⁸U?

3-4.  How many protons neutrons and electrons are in ⁶⁵Zn²⁺?

4.  Calculate empirical formulas from % composition.  If MM is given, be able to convert empirical formula to molecular formula
 

4-1.  A sample of a compound is found to contain 2.38 g nitrogen and 1.36 g oxygen.  What is the simplest formula?

4-2.  A 0.2000 g sample of vitamin C which contains only C, H, and O, is reacted completely with oxygen to give 0.2999 g CO2 and 0.08181 g H2O.  What is the empirical formula of vitamin C?

4-3.  A compound contains 46.74% O, 51.79% Cl and 1.472 % H.  What is this compound's empirical formula?

4-4.  A sample of iron oxide analyzed to be 70.0% iron by mass.  What is the empirical formula of the sample?

4-5.  An oxide of nitrogen contains 36.86% N.  What is its empirical formula?

5.  Balance equations and perform mole/mole relationship calculations.  Also, you may need to start or finish with grams instead of moles (just a little extra work)
 

5-1.  How many moles of F2 are required to combine with 3.11 mol Xe to produce XeF4?

5-2.  How many moles of oxygen are needed to combust 13.0 mol benzene, C6H6:

C6H6 + O2   CO2 + H2O (unbalanced)

5-3.  How many grams of oxygen are needed to react with 21.4 g chromium in order to produce the paint pigment chromium oxide, Cr2O3?

5-4.  How many grams of HCl are needed to react with 6.25 g Al according to:

2 Al + 6 HCl  2 AlCl3 + 3 H2

5-5.  How many moles of oxygen atoms are contained in 63.5 g of Cl2O7?

5-6.  The reaction between methane and oxygen to produce CO is given as:

2 CH4 + 3 O2  2 CO + 4 H2O.  
            How many grams of oxygen will be consumed in the production of 45 g CO?

5-7.  A mixture of 54 g aluminum and 32 g oxygen were reacted to completion according to

 4 Al + 3 O2  2 Al2O3.              Which reagent was in excess and by how much?

6. Limiting Reagents/Theoretical Yield

6-1.  A mixture containing 3.22 g CS2 and 7.61 g Cl2 is allowed to react according to the reaction given below.  How many grams of CCl4 are formed? CS2 + 3 Cl2  CCl4 + S2Cl2

6-2.  How many moles of NH3 will be produced when 8.94 mol H2O are produced according to:

Ce2O3 + 6 NH4Cl  2 CeCl3 + 3 H2O + 6 NH3

6-3.  Ammonia burns in oxygen according to the equation:

4 NH3 + 3 O2  2 N2 + 6 H2O

 
If 2.0 mol NH3 and 3.0 mol O2 are mixed and the reaction goes to completion, the resulting mixture will contain how many mol of each reactant and product?

7.  Theoretical Yield and Percent Yield

7-1.  The reaction of 25.0 g benzene, C6H6, with excess HNO3 resulted in 21.4 g C6H5NO2.  What is the percent yield?  The equation is: C6H6 + HNO3  C6H5NO2 + H2O

7-2.  If 1.00 g Cu is heated with 1.00 g sulfur according to

 2 Cu + S Cu2S  What is the % yield if 1.00 g Cu2S is obtained?

8. Know the names of common ions and be able to name simple salts.
Know these:  ammonium sulfate nitrate carbonate phosphate acetate nitrite sulfite permanganate

9.  Know atomic symbols of important elements.
H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Cr, Fe, Co, Ni, Cu, Zn, Br, Kr, Ag, Xe, Ba, Au, Hg, Pb, Bi, U

10.  Solve problems involving the ideal gas law, PV=nRT.
  [Note: You will be given R = 0.0821 L atm/mol K]
 

10-1.  A gas at 25oC and 680 torr occupies 345 mL.  How many moles are present?

10-2.  A sample of gas occupies 30.0 L at 0.800 atm and 298 K.  How many moles of gas are in the sample?

10-3.  How many liters of chlorine gas can be produced by the electrolysis reaction of 6 mol NaCl at 27^oC and 1 atm?

2 NaCl(s)   2 Na(s) + Cl2(g)

10-4.  What is the volume in L occupied by 1.00 g of methane, CH4, at STP?

10-5.  Compute the mass of 6.00 L of ammonia gas, NH3 at STP.

11.  Gas Molecular Mass. Using the ideal gas law PV = nRT where n is replaced with m/MM to solve problems regarding molecular mass: MM = mRT/PV.

11-1.  A 205 mL sample of gas at 100^oC and 755 torr is found to have a mass of 1.22 g.  What is the molecular weight of the gas?

11-2.  A 1.67 g sample of a volatile unknown liquid is collected as a vapor in a container having a volume of 0.421 L.  The sample is collected at 125^oC and 749 torr.  Calculate the molecular weight.

11-3.  Determine the MW of a 560 mL gas sample that has a mass of 1.80 g at STP.

11-4.  At 750 torr and 27^oC, a 0.60 g sample of a gas occupies 0.50 L.  Calculate its MM.

11-5.  What mass of gas X (MM=26.5 g/mol) occupies 9.84 L at a pressure of 172 torr and 27^oC?

12.  Gas Density. Use the ideal gas law PV = nRT where n is replaced with m/MM which gives MM = mRT/PV but since m/V is the density, the equation to use is MM= dRT/P or d = P MM/RT where d = density in g/L.

12-1.  A gas has a density of 2.86 g/L at STP.  Which of the following could it be? O2     SO2     CO2     AsH3

12-2.  What is the molecular mass of a gas if its density is 2.47 g/L at 747 torr and 38^oC?

12-3.  Calculate the MW of a gas which has a density of 1.48 g/L at 100^oC and 600 torr.

12-4.  Determine the density of H2S gas at 27^oC and 2.00 atmospheres pressure.

13. A change in the System. Solve problems involving the equation PiVi/niTi = PfVf/nfTf :

13-1.  A gas at 750 torr and with a volume of 2.00 L is allowed to change its volume at constant temperature until the pressure is 600 torr.  What is the new volume of the gas?

13-2.  A sample of gas with a volume of 800 mL and pressure of 1.00 atm is brought to a volume of 250 mL at constant temperature.  What is the final pressure of the gas?

13-3.  If the volume of a gas at 323 K is changed from 780 mL to 620 mL at constant pressure, what will be the new temperature of the gas?

13-4.  A quantity of gas initially at a temperature of 30.0^oC is compressed from a volume of 1.00 L to 0.750 L, while its pressure is increased from 1.60 to 2.00 atm.  What is the resulting temperature?

13-5.  If the volume of an ideal gas is 2.0 L at 0.50 atm pressure, what is the final pressure if the volume increases to 5.0 L?

13-6.  If the pressure of a gas is 2.0 atm at 27 ^oC, what will the pressure of this gas be if the volume remains constant and the temperature is increased to 227 ^oC?

13-7.  A 0.787 g sample of gas is placed in 422 cm³ container at 42.0 ^oC where it exerts a pressure of 0.750 atm.  What pressure will be exerted by the gas if it is expanded to a volume of 844 cm³ at a temperature of 21.0 ^oC?

13-8.  A sample of gas in a size-adjustable container occupies 500 L.  If the pressure is quadrupled and the temperature is reduced to 1/3 its original value, what is the new volume?

14.  Determine the relative rates of effusion/diffusion between two gases.

14-1.  What is the relative rate of effusion of hydrogen gas to helium gas?

14-2.  The rate of effusion of gas X is found to be about 1.3 times that of SF6(g).  What is the molecular weight of X?

14-3.  How many times faster does H2  effuse through a pinhole than does CO?

15.  Quantum numbers: Be able to determine:
  a. if a set of quantum numbers is allowed or not allowed
  b. which orbital designation is correct
  c. orbital shapes (for s and p only).
 

15-1.  What are the possible values for l for an electron with n=3?

15-2.  What are the possible values for n for an electron with 1=3?

15-3.  How many electrons can be in a shell with n=5?

15-4.  What shell (n=?) would be the first to have a 'g' subshell?

15-5.  What is wrong (if anything) with these sets of quantum numbers as possible designations of a 3d electron?
   n l ml ms
  a. 3 3 -2 0
  b. 3 1 0 -1/2
  c. 3 2 3 1/2
  d. 3 2 -2 -1/2

15-6.  What is wrong with these sets of quantum numbers as possible designations for the outermost electrons of germanium, Ge?
   n l ml ms
  a. 4 1 -2 -1/2
  b. 3 1 0 -1/2
  c. 4 2 3 1/2
  d. 3 2 -2 -1/2

15-7.  What is the principal quantum number for the last electron added to the element iodine?

16.  Give/recognize acceptable electronic configurations of atoms or ions.  Be able to determine the number of unpaired electrons in an element.  Know the maximum number of electrons possible for a given set of quantum numbers.

16-1.  Classify each of the following atom (or ion)/electronic configuration combinations as ground state, excited state, or not allowed
  a.  Ga [Ar] 4s² 3d¹²
  b.  Ni [Ar] 4s² 3d⁸
  c.  S2- [Ne] 3s² 3p⁶
  d.  N 1s² 2s¹ 2p⁴

16-2.  Which of the following has one or more unpaired electron(s) in the ground state?

Be    K⁺    Cd    Se    S^2-

16-3.  Give the complete electronic configuration for calcium.

16-4.  What atom has this electronic configuration: [Ar] 4s² 3d¹⁰ 4p³?
 

17-1.  Select the largest species of each of these groups:
 a. Ti²⁺ Ti³⁺ Ti
 b. F^- Ne Na⁺

17-2.  Which has the largest first ionization energy for each of these groups:
 a. Na K Rb
 b. F Ne Na

17-3.  Select the smallest species of the group:
 Li⁺ Na⁺ K⁺ Be⁺² Mg⁺²

17-4.  Which has the lowest first ionization energy for the group?
  K Ca Se Br Kr

17-5.  Which set is listed in order of increasing effective nuclear charge?
  a.  O, C, N b.  B, C, O c.  F, Cl, Br d. F, S, As

18.  Use the periodic table to predict the formula of a compound

18-1.  What is the correct formula for magnesium phosphide?

18-2.  What is the correct formula for magnesium carbonate?

18-3.  What is the correct formula for aluminum oxide?

18-4.  What is the correct formula for sodium sulfate?
 

19-1.  How many electrons should be in the Lewis structure of the phosphate ion, PO4^-3?

19-2.  Which of the following has lone pairs of electrons on the central atom?

ICl3   NF3   CO2   CCl4

19-3.  In which of the following is the actual structure a resonance hybrid of Lewis structures?

O=C=O  H-O-H  O=S-O  CCl4

19-4.  Which of the following molecules do not obey the octet rule?

a.  NF3  b.  SF4  c.  PF4+  d.BF3

19-5.  How many resonance forms are possible for each of these without expanding the octet?

a.  CO3^-2   b.  NO2¹   c.  SO4^2-

19-6.  Which compound has only one lone pair on the central atom?

SF2   SiF4   NF3   XeO4   PF4⁺

20. Polarity:  Determine if molecular polarity exists for a given covalent compound

20-1.  Draw the Lewis dot structure for each of the following compounds.  Determine it the compound is polar.

a.  NF3  b.  SF2  c.  SiF4  d.  CS2

21.  Use the VSEPR model to predict the structural group or name for a given molecule or polyatomic ion.  Use the VSEPR model to answer questions about the molecule's polarity and bond angles.
21-1.  What are the bond angles in the following molecules/ions?

SeBr2   SO3   CO2   SO3^2-

21-2.  What are the names of the molecular shapes associated with the symbolic formula AB3 and AB3E?

21-3.  What is the shape of the following molecules?

ClF3    PH3   TeCl2  CO2   SiF4

21-4.  What is the ABnEm designation for the following molecules?

CCl4   PF2^-   TeCl2  XeO4  SO2

21-5.  Which of the following molecules is polar?

CH4   BF3   XeO4   SO2

22.  From the structure of a covalent molecule be able to determine the number of s and p bonds and the hybridization about the central atom.

22-1.  What is the hybridization associated with the following shapes?
a.  trigonal pyramid b.  trigonal bipyramid c.  trigonal plane

22-2.  What is the hybridization predicted for the sulfur in SO3^2-?

22-3.  What angles exist between orbitals in sp³ hybrid orbitals?

22-4  Which of the following uses sp³d hybrid orbitals on the central atom?

SF5-    PF6-    IF5    SiF4    AsCl5

22-5.  The molecule C2H2 contains ____ s bonds and ____ p bonds.

22-6.  The molecule C2H4 contains ____ s bonds and ____ p bonds.
 

23-1.  In the thermite reaction: 2 Al + Fe2O3  Al2O3 + 2 Fe  DH = -849 kJ, how much heat is produced at the same time 100.0 g Fe is produced?

23-2.  Given that 2 Mg + O2  2 MgO DH = -1205 kJ, how many grams of magnesium would you have to burn to produce 837 kJ of heat?

23-3.  Given that H2(g) + Cl2(g)  2 HCl(g) DH = -185 kJ, what is the heat of formation of HCl?

23-4.  How much heat will be required to make 1.000 kg CaC2 from CaO(s) and C(s)?
CaO(s) + 3 C(s)  CaC2(s) + CO DH = +466 kJ

23-5.  Calculate the mass of mercury which can be liberated from HgO at 25^oC by the treatment of excess HgO with 41.84 kJ heat.  HgO(s)  Hg + 1/2 O2(g) DH = +90.8 kJ
 

24-1.  Given these two reactions:
 

 X(s) + O2(g)  XO2(g) DH^o = -297 kJ.mol
 
2 X(s) + 3 O2(g)  2 XO3(g) DH^o = -792 kJ.mol

Calculate DHo for the reaction

 XO2(s) + 1/2 O2(g)  XO3(g) DH^o = ?

24-2.  Given these two reactions:

 H2(g) + Cl2(g)  2 HCl(g)  DH^o = -185 kJ.mol
 2 H2(g) + O2(g)  2 H2O(l)  DH^o = -572 kJ.mol
 

Calculate DHo for the reaction

 4 HCl(g) +  O2(g)  2 Cl2(g) + 2 H2O DH^o = ?

24-3.  Given these two reactions:

 SO3(g) + H2O(l)  H2SO4(l)    DH^o = -133 kJ.mol
 Pb(s) + PbO2(s) + 2 SO3(g)  2 PbSO4(s)  DH^o = -775 kJ.mol

Calculate DHo for the reaction

 Pb(s) + PbO2(s) + 2 H2SO4(l)  2 PbSO4(s) + 2 H2O(l)  DH^o = ?

25.  Given the standard enthalpies of formation, DHf^o, for a variety of compounds, determine the enthalpy of a given reaction.  [Note: Use the Appendix for the thermodynamic data]

25-1.  Using heat of formation data calculate DH^o for the following reaction.

  Na2CO3(s) + 2 HCl(g)  H2O(l) + CO2(g) + 2 NaCl(s)

25-2.  What is DHo for the following reaction?

  CH4(g) + 2 O2(g)   CO2(g) + 2 H2O(l)

25-3.  Calculate DHo for the reaction:

  3 H2O(l) + 2 CO2(g)  C2H5OH(l) + 3 O2(g)

25-4.  Calculate DHo for the reaction:

  CaCO3(s)  CaO(s) + CO2(g)

Answers:
 1-1 1.61 dol
1-2 1160 cm³
1-3 3.85 mL
1-4 150 mg
1-5 9.0 m
2-1 25.4
2-2 4
2-3 3
2-4 4
2-5 104
3-1 27 p + 29 n + 24 e
3-2 17 p + 20 n + 18 e
3-3 92 p + 146 n + 92 e
3-4 30 p + 35 n + 28 e
4-1 N2O
4-2 C3H4O3
4-3 HClO2
4-4 Fe2O3
4-5 N2O3
5-1 6.2 mol F2
5-2 97.5 mol
5-3 9.88 g
5-4 25.3 g
5-5 2.43 mol
5-6 77 g
5-7 Al, 18 g excess
6-1 5.50 g
6-2 17.9 mol
6-3 1.5 mol O2 + 1 mol N2+ 3 mol H2O
7-1 54.3 %
7-2 80 %
10-1 0.0126 mol
10-2 0.981 mol
10-3 74 L
10-4 1.40 L
10-5 4.55 g
11-1 183 g/mol
11-2 132 g/mol
11-3 72 g/mol
11-4 30 g/mol
11-5 2.40 g
12-1 SO2
12-2 64.2 g/mol
12-3 57.4 g/mol
12-4 2.76 g/L
13-1 2.50 L
13-2 3.20 atm
13-3 257 K
13-4 11oC
13-5 0.20 atm
13-6 3.3 atm
13-7 0.350 atm
13-8 41.7 L
14-1 1.4:1.0
14-2 86 g/mol
14-3 3.74
15-1 l=0,1,2
15-2 n>3
15-3 n=5, l=0,1,2,3,4: 50 electrons
15-4 n=5
15-5 l=2 for 3d; ml ranges -2 to +2
15-6 4p: n=4; l=1; ml=-1,0,1
15-7 n=5
16-1a not allowed
16-1b ground
16-1c ground
16-1d excited
16-2 Se
16-3 1s22s22p63s23p64s2
16-4 As
17-1 Ti, F-
17-2 Na, Ne
17-3 Be2+
17-4 K
17-5 b
18-1 Mg3P2
18-2 MgCO3
18-3 Al2O3
18-4 Na2SO4
19-1 32
19-2 ICl3, NF3
19-3 SO2
19-4 SF4, BF3
19-5 3,2,0
19-6 NF3
20-1a. polar;  20-1b. polar
20-1c. non-polar;  20-1d. non-polar
21-1a. 109.5o 21-1b 120o
21-1c 180o  21-1d 109.5o
21-2 trig plane, trig pyramid
21-3 T-shape, trig pyr, bent, lin., tetrahd
21-4 AB4, AB2E2, AB2E2, AB4, AB2E
21-5 SO2
22-1 sp3, sp3d, sp2 22-2 sp3
22-3 109o   22-4 AsCl5
22-5 3 s 2 p  22-6 5 s 1 p
23-1 -761 kJ  23-2 33.8 g
23-3 -92.5 kJ  23-4 7280 kJ
23-5 92.4 g
24-1 -99 kJ  24-2 -201 kJ
24-3 -509 kJ
25-1 -189 kJ  25-2 -891 kJ
25-3 1364 kJ  25-4 178 kJ