2009 Chemistry Midterm Review Packet
Complete the following 110 problems and questions as a Midterm Review. Turn in this packet of worked problems on Friday, March 27th. This will be a 200 point Quiz Grade.
For problems, show ALL of your work. For Questions, answer in complete sentences.
Chapter 4, pages 118-120
# 1, 3, 4, 6, 8b,d,f, 9b,d,f, 10, 17a,b,c, 29, 32
1. contains 2 elements; look for 3 examples of binary
3. cation; anion
4. cation (+ ion)
6. a) sodium chloride; b) calcium fluoride; c) aluminum fluoride; d) calcium bromide;
e) strontium oxide; f) silver chloride; g) cesium iodide; h) lithium oxide
8. b) manganese (II) chloride; d) copper (I) oxide f) tin (IV) bromide
9. b) chromium (III) bromide d) tin (IV) oxide f) iron (III) chloride
10. a) iodine pentafluoride; b) arsenic trichloride; c) selenium monoxide;
d) xenon tetrafluoride; e) nitrogen triiodide; f) diboron trioxide
17. a) NO3- b) NO2- c) NH4+
29. a) LiCl b) Cu2CO3 c) HBr d) Ca(NO3)2 e) NaClO4 f) Al(OH)3 g) Ba(HCO3)2 h) FeSO4 i) B2Cl6 j) PBr5 k) K2SO3 l) Ba(C2H3O2)2
32. a) gold (III) bromide b) cobalt (III) cyanide c) magnesium hydrogen phosphate
d) diboron hexahydride e) ammonia f) silver sulfate g) beryllium hydroxide
Chapter 5, pages 164-167
# 3, 5, 9, 13, 21-23, 24, 27, 32, 51, 54, 58, 61
3. a) 0.06235 b) 7229 c) 0.000005001 d) 86,210
5. a) 9.367421 x 106 b) 7.241 x 103 c) 5.519 x 10-4 d) 5.408 X 100
e) already in scientific notation f) 6.319 x 101 g) 7.215 x 10-9 h) 7.21 x 10-1
9. a) 103 b) 10-2 c) 10-3 d) 10-1 e) 10-9 f) 10-6
13. 5.22 cm
21. 40 quarters
22. 2.85 cm (5 is an estimated digit)
23. 2.850 (0 estimated digit)
24. a) 4 b) 5 c) 4 d) 1 e) 3 f) 3
g) 6 h) 5
27. a) 3.42 x 10-4 b) 1.034 x 104 c) 1.7992 x 101 d) 3.37 x 105
32. a) 641.0 b) 1.327 c) 77.34 d) 3215
51. volume
54. density is a characteristic property of a pure substance
58. 2.68 g/mL
61. a) 23.1 cm3 b) 3.68 cm3 c) 56.8 cm3 d) 4.76 cm3
Chapter 6, pages 210-212
# 3, 8, 17, 19, 23, 28, 32
3. atomic mass unit; 1.66 x 10-24 g
8. 1.205 x 10^24 atoms
17. molar mass
19. a) 82.98 g b) 76.15 g c) 97.94 g d) 46.07 g e) 82.09 g f) 98.09 g
23. a) 612 g b) 0.149 g c) 721 g d) 2.10 x 10^7 e) 373 g
28. a) 28.45% Cu b) 44.29% Cu c) 44.06 % Fe d) 34.43 % Fe e) 18.84 % Co f) 13.41 % Co g) 88.12 % Sn h) 78.77 % Sn
32. Empirical – smallest whole number ratio
Molecular – actual number of atoms in molecule
Chapter 7, p. 234 – 236
# 1, 5 – 8, 11, 13, 16, 27, 33, 35, 40, 45
1. Chemical change is a process in which a given substance changes into a different substance. Evidence includes formation of a solid; bubbles; color change; heat
5. reactants, products
6. atoms
7. gaseous
8. water
11. H2 + O2 à H2O
13. Ag2O + Ag à O2
16. Ca + H2 à CH3OH
27. PbS + O2 à PbO + SO2
33. a) 2H2O à 2H2O + O2 b) 2Ag + H2S à Ag2S + H2
c) 2FeO + C à 2Fe + CO2 d) Cl2 + 2KI à 2KCl + I2
35. a) SiI4 + 2Mg à Si + 2MgI2 b) MnO2 + 2Mg à Mn + 2MgO
c) 8 Ba + S8 à 8BaS d) 4NH3 + 3Cl2 à 3NH4Cl + NCl3
40. 2H2 + CO à CH3OH
45. 2H2O2 à H2O + O2
Chapter 8, pages 271 – 276
# 11, 13, 25, 27, 30, 34-36, 51
11. a) no reaction b) (NH4)2S + CoCl2 à CoS + 2NH4Cl
c) H2SO4 + Pb(NO3)2 à PbSO4 + 2HNO3 d) CaCl2 + K2CO3 à CaCO3 + 2KCl
e) no reaction f) Na3PO4 + CrCl3 à CrPO4 + 3NaCl
13. a) (NH4)2S + CoCl2 à CoS + 2NH4Cl
b) FeCl3 + NaOH à Fe(OH)3 + 3NaCl
c) CuSO4 + Na2CO3 à Na2SO4 + CuCO3
25. metals lose e-; non-metals gain e-
27. Aluminum atoms each lose 3 e- for a total of 6 lost; each Br2 gains 2 e- for a total of 6 gained.
30. Double replacement – 2 compounds form 2 new compounds
Single replacement – element gets replaced by more reactive element. (look for 2 good examples of each)
34. Synthesis – one product from several reactants
Need an example of synthesis which is also combustion like C + O2 à CO2; Need an example of synthesis which is also redox, but NOT combustion, so doesn’t involve oxygen as a reactant.
35. Decomp – opposite of synthesis; example
36. a) C2H5OH + 3 O2 à2 CO2 + 3 H2O b) 2C6H14 + 19 O2 à 12 CO2 + 14H2O
c) C6H12 + 9 O2 à 6 CO2 + 6 H2O
51. a) acid-base; b) precip; c) redox/comb/synth; d) redox/decomp
(note: only one answer needed for each letter)
Chapter 9, pages 310-316
# 6-7, 9, 11, 15, 17, 19, 21, 23, 26, 31, 32, 34, 40, 42, 43, 48, 52, 55, 67
6. 2 mol O2 / 1 mol CH4; 1 mol CO2/1 mole CH4; 2 mol H2O / 1 mol CH4
7. 2 Ag + H2S à Ag2S + H2; For Ag2S = 1 mol Ag2S / 2 mo Ag; for H2 = 1 mol H2 / 2 mol Ag
9. a) 0.50 mol NH4Cl (27g) b) 0.125 mol CS2 (9.5 g); 0.25 mol H2S (8.5 g)
c) 0.50 mol H3PO4 (41 g); 1.5 mol HCl (55 g) d) o.50 mol NaHCO3 (42 g)
11. molar mass
15. a) 1.03 molCuCl2 b) 0.0735 mol NiCl2 c) 0.240 mol NaOH d) 0.250 mol HCl
17. 500. g H20
19. 18.3 g CO2; 11.7 g CO
21. 4.704 g O2
23. 0.437 g N2; 0.250 g O2; 0.562 g H2O
26. 3.26 x 10-3 g Cl2
31. use masses given to calculate # moles of each reactant. Use mole ratio in balanced equation to decide which is limiting.
32. once limiting reactant is consumed, reaction can no longer proceed and no more product can be formed.
40. actual yield is quantity of product actually isolated from reaction. Theoretical yield represents the maximum quantity of product possible if the reaction proceeds to completion. Percent yield represents ratio of actual yield to theoretical yield.
42. 85.4%
43. 25.2 g Na2S2O3 * 5 H2O; 20.9% yield
48. 8.26 g FeS
52. a) 0.50 mol H2O, 0.25 mol O2 b) 0.50 mol KCl, 0.75 mol O2
c) 0.50 mol AlCl3; 0.75 mol H2 d) 1.5 mol CO2; 2.0 mol H2O
55. 4.6 x 102 g O2
67. a) add more Na, get more product because Na is limiting reactant. Eventually Na becomes excess and no longer impacts the reaction.
b) 50.84 g NaCl c) 61.68 g Cl2 d) 101.68 g NaCl e) part b, sodium is limiting and 30.84 g Cl2 is left over. In part D, Cl2 is limiting and 10.00 g Na is left over.
Chapter 10, pages 353 – 356
# 1, 5, 6, 9 – 11, 13-15, 22, 24, 26, 27, 47, 48, 50, 52, 58, 65
1. Kinetic energy is energy of motion while potential energy is energy of position.
5. Energy is conserved in any process, the pathway of the process does not matter. Thus energy is a state of function.
6. Heat is a flow of energy due to temperature difference. Temperature is a measure of the average kinetic energy of a substance. Thermal energy comes from the random motion of the components of the substance.
9. There is more heat involved in mixing 100.0 g samples of 60°C and 10°C water because there is a larger temperature difference.
10. The final temperature should be less than 90°C and greater than 50°C. If the water samples had equal mass, the final temperature would be the average of the two (50°C). Because we have more of the warmer water, the final temperature will be higher than the average of the two.
11. The potential energy is the energy available to do work. Potential energy in a chemical reaction is stored in the chemical bonds.
13. The reactants
14 a) endothermic
b) exothermic
c) exothermic
d) endothermic
15. The process is exothermic; The process is endothermic.
22. In ice, the water molecules are held together rigidly in fixed positions. As the sample is heated, the molecules vibrate but stay in their positions until the melting point is reached. Once the melting point is reached, the molecules move around much more freely (although they are still held together). As more heat is applied, the molecules move more quickly and freely until the boiling point is reached. When the individual molecules are moving quickly enough to overcome the forces holding them together, they escape from the liquid. As the molecules of the vapor are heated, they move more and more quickly.
24. 1.70 x 103 J
26. 0.711 J/g°C
27. Gold (it has the smallest specific heat capacity)
47. a) 110.5 kcal
b) 17.43 kJ
c) 657.5 cal
d) 2.394 x 104 J
48. 7.64 x 103 cal
50. 11°C
52. 3.8 x 105 J
58.
Substance / Temperature ChangeWater (l) / 23.9°C
Water (s) / 49.3°C
Water (g) / 50.°C
Aluminum / 1.1 x 102 °C
Iron / 2.2 x 102 °C
Mercury / 7.1 x 102 °C
Carbon / 1.4 x 102 °C
Silver / 4.2 x 102 °C
Gold / 7.7 x 102 °C
65. a) 1460 J
b) We assume these to be the same.
c) The initial temperature is 100.0°C and the final temperature is 21.31°C.
d) 0.388 J/g°C
e) The metal is zinc.
Chapter 15, pages 555-558
# 2, 3, 5-7, 11, 12b,d, 13b,d, 20, 22, 27, 30, 31, 49, 51, 53, 60
2. solvent; solute
3. When an ionic solute dissolves in water, a given ion is pulled into solution by the attractive ion-dipole forces exerted by several water molecules. Although the ionic forces in the crystal are stronger than the ion-dipole forces, entropy is also a driving force for an ionic solid to dissolve, because the solution is more disordered than the pure water and solid ionic crystal. After entering the solution, the dissolved ion is surrounded completely by water molecules, which tends to prevent the ion from reentering the crystal.
5. saturated
6. unsaturated
7. variable
11. An increase in temperature means an increase in the average kinetic energy. In a warmer solution, the solvent and solute particles are moving more rapidly. If the solute particles are gaseous, faster-moving particles are more likely to have enough energy to escape from the liquid.
12. b) 5.00% CaCl2
d) 5.00% CaCl2
13. b) 0.719 g NaCl
d) 55.6 g NaCl
20. A 5.00 M solution means there are 5.00 moles of solute per 1.00 L of solution (not water). To make such a solution, we would add enough water to 5.00 moles of solute so that the total volume of the solution is 1.00 L.
22. a) 0.253 M
b) 0.106 M
c) 0.434 M
d) 1.7 x 10-3 M
27. a) 0.0133 mol; 0.838 g
b) 2.34 mol; 39.9 g
c) 0.00505 mol; 0.490 g
d) 0.0299 mol; 1.09 g
30. 4.25 g
31. a) 0.0837 M
b) 0.320 M
c) 0.0964 M
d) 0.622 M
49. Colligative properties are properties of a solution that depend only on the number (not the identity) of the solute particles.
51. Antifreeze solution is a concentrated aqueous solution that has a lower freezing point than water. It also as a higher boiling point than water (a solute in water both lowers the freezing point and raises the boiling point).
53. 0.072 g AgCl; 1.2 M Ag+
60. [A] > [D] >[C]>[B]