Keys to Previous Tests

Test One, January 26, 1999

1. a.) 3.601 x 10^-2
   b.) 3.621 x 10⁸
   c.) 3.26 x 10^-5
   d.) 4.63 x 10^-2
   e.) 3.12 x 10⁴

2. 23 ^oC and 3.0 x 10² K

3. 0.575 liters

4. protons  electrons  neutrons
a.)  11        11         12
b.)  24        24         30
c.)  27        27         33

5. a.) sodium  b.) scandium  c.) silicon  d.) barium  e.) selenium

6. a.) Au  b.) Cl  c.) O  d.) P

7. a.) iron(II)oxide  b.) chromium (VI) oxide  c.) nitrogen triiodide
   d.) trihydrogen phosphate  e.) iron(III)phosphate  f.) potassium permanganate

8. a.) LiOH  b.) Al₂O₃  c.) CaCl₂  d.) Na₂SO₃

9. a.) +1, cation  b.) +2, cation  c.) -1, anion  d.) +3 cation  e.) -2 anion

10. a.) nitric acid  b.) phosphoric acid  c.) acetic acid  d.) hydrocholoric acid
    e.) hydrocyanic acid

11. Isotopes = atoms having the same atomic number, Z, but a different mass number.
    Ion = electrically charged atoms or groups of atoms
    Theory = a model that explains a body of facts and the laws based upon them.
    Any model is an invention of the human mind and can drastically change when
    new facts are discovered.
    Chemical change = a change in which one or more substances change into one
    or more different substances.
    Physical change = a change in which the substances maintain their identity.

12. Volume = 44.3 cm³

13. a.) 467  b.) 33.04  c.) 1.7 x 10^-1

*************************************************

Test Two, Spring Semester, 1999

1. 108.9 amu

2. 26.4 g

3. a.) 3Fe₂O₃ + 1 CO --> 2 Fe₃O₄ + 1 CO₂
   b.) 1 Ca + 2 H₂ --> 1 Ca(OH)₂ + 1 H₂
   c.) 2 C₄H₁₀ + 13 O₂ + 10 H₂O
4. a.) Ag⁺ + Cl^- --> AgCl
   b.) Fe⁺⁺⁺ + 3 OH^- --> Fe(OH)₃

5. a.) Ag is the limiting reagent
   b.) 2.29 g Ag₂S
   c.) 70% yield

6. C₃H₆O₂

7. 1.78 M

8. Take 40 ml of the 2.00M solution and add 160 ml water.

9. a.) 2NH₄⁺   SO₄^-2
   b.) HI
   c.) Fe⁺²  SO₄^-2
   d.) H⁺  ClO₄^-
   e.) Mg⁺²  2Cl^-

10. a.) 1 BaCl₂ + 1 Na₂SO₄ --> BaSO₄ + 2 NaCl
    b.) 2 HCl + 1 Mg(OH)₂ --> MgCl₂ + 2 H₂O

11. 1.080 M

12. 10Br^- + 16H⁺ + 2MnO₄^- --> 5Br₂ + 2Mn²⁺ +  H₂
     Oxidized: 2Br^- --> Br₂
     Reduced: MnO₄^- --> Mn²⁺

***************************************************

Test Three, Spring Semester, 1999

1. density = 0.00328 g/cm³

2. P₂ = 51200 torr

3. a.) P_hydrogen = 1.126 atm   P_helium = 0.332 atm
   b.) V = 160. liters

4. a.) Kinetic energy = 121 joules
   b.) Potential energy = 14.6 joules
   The assumption regarding potential energy is that the zero point is taken to be at Z = 0.

5. a.) deltaE = 21 kj, heat flows in and work flows out
   b.) deltaE = -49 kj, heat flows out and work flows in

6. T₂ = 261^oC

7. deltaH^o = -58.0 kj

8. a.)deltaH^o = -305 kj
   b.)delataH^o_f of N₂O₄ is approximately 10. kj.
   (by the way, the experimental value is 9.16 kj)

**************************************************

Test Four, Spring Semester, 1999

1. n = 1,2,3,4,....
   l = 0,1,2,...,n-1
   m_l = -l,-l+1,....0,...,+l

2. not allowed are: 1p, 3f, 2d

3. frequency = 3.84 x 10¹⁴

4. a.) wavelength = 657 nm
   b.) wavelength = 486 nm

5. wavelength = 365 nm

6. a.) 1s²2s²2p²
   b.) 1s²2s²2p⁶3s²3p⁶4s²
   c.) 1s²2s²2p⁶3s²3p⁶4s²3d³
   d.) 1s²2s²2p⁶3s²3p⁶4s¹3d¹⁰

7. a.) diamagnetic
   b.) paramagnetic
   c.) diamagnetic
   d.) paramagnetic

8. a.) Be less than Mg less than Ca
   b.) Ge less than Ga less than I

9. a.) Ca less than Mg less than Be
   b.) I less than Ga less than Ge

10. No --  excited state, 1s²2s²2p³