3. Which of the following compounds is soluble? The solubility rules are listed on page 8.

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1 1. Classify the following reaction. Sb 2 O Fe 2 Sb + 3 FeO a) Combination reaction b) Decomposition reaction c) Neutralization reaction d) Single-replacement reaction e) Double-replacement reaction 2. Which of the following reactions is a Redox reaction? All are double-replacement rxns except b. Rxns c and e are also called neutralization reactions. a) HCl (aq) + AgNO 3 (aq) HNO 3 (aq) + AgCl (s) b) WO H 2 W + 3 H 2 O c) Ba(OH) 2 (aq) + H 2 SO 4 (aq) BaSO 4 (s) + 2 H 2 O (l) d) BaBr 2 (aq) + Pb(NO 3 ) 2 (aq) Ba(NO 3 ) 2 (aq) + PbBr 2 (s) e) NaOH + HBr H 2 O + NaBr 3. Which of the following compounds is soluble? The solubility rules are listed on page 8. a) Hg 2 Cl 2 b) PbSO 4 c) K 2 S d) Fe(OH) 2 e) Mg 3 (PO 4 ) 2 4. When an aqueous solution of potassium sulfate is mixed with an aqueous solution of lead nitrate a precipitate is formed (consult the solubility rules on page 8). Which are the spectator ions for this reaction? K 2 SO 4 (aq) + Pb(NO 3 ) 2 (aq) 2 KNO 3 (aq) + PbSO 4 (s) net ionic eqn: Pb 2+ + SO 4 2- PbSO 4 a) none are spectator ions b) Pb 2+ and NO 3 - c) Pb 2+ and SO 4 2- d) K + and SO 4 2- e) K + and NO 3-5. What is the oxidation number for sulfur in Na 2 SO 3? 2(+1) + S + 3(-2) = 0 S = +4 a) -2 b) -4 c) +6 d) +4 e) Balance the following equation. What is the sum of the coefficients of the reactants and products? 4 NH O 2 4 NO + 6 H 2 O a) 12 b) 15 c) 19 d) 20 e) 22 1

2 7. Which of the following statements is NOT correct for the reaction of sodium hydroxide with sulfuric acid? 2 NaOH (aq) + H 2 SO 4 (aq) Na 2 SO 4 (aq) + 2 H 2 O (l) a) The above equation is properly balanced. b) A neutralization reaction occurred. c) The net ionic equation is H + + OH - H 2 O d) This is a double-replacement reaction. e) Hydrogen ions and hydroxide ions are spectator ions. 8. Which of the following statements correctly describes what happens when a solution of sodium bromide is mixed with a solution of iodine? 2 NaBr (aq) + I 2 (aq) a) No reaction occurs. Recall: b) NaI (aq) is formed. Reactivity of halogens c) A redox reaction occurs. F > Cl > Br > I d) Sodium iodide precipitates I 2 cannot replace Br - e) The reaction produces Br Identify the oxidizing agent in the following oxidation-reduction reaction. (+3)(-2) (0) (+3)(-2) (0) Fe 2 O Al Al 2 O Fe a) Fe 3+ b) O 2- c) Al d) Al 3+ e) Fe 10. Which of the following reactions is an oxidation? O O a) CH 3 C OH CH 3 C H b) CH 2 CH 2 H C C H Loss of hydrogen atoms = oxidation O c) CH 3 C H CH 3 CH 2 OH d) CH 3 CH 2 -OH CH 3 CH 3 e) CH 2 CH 2 CH 3 CH 3 2

3 11. How many grams of NaBO 3 are in 4.65 moles? (Atomic weights: B = 10.81, O = 16.00, Na = 22.99) Fw = 81.8 a) 74.4 b) 112 c) 223 d) 380 e) g x 4.65 mol 1 mol 12. To three significant figures, what is the percent of calcium ions in Ca 3 (PO 4 ) 2? (Atomic weights: Ca = 40.08, O = 16.00, P = 30.97) a) 12.9 b) 25.8 c) 38.8 d) 54.5 e) 61.2 Fw Ca 3 (PO 4 ) x Ca 2+ 3 x x 100 Ca 3 (PO 4 ) A hospital patient is given a solution containing 9.00 x 10-9 g of iodine-131 (isotopic weight: 131). How many atoms of iodine are present? Avogadro s Number = 6.02 x a) 4.14 x b) 4.14 x c) 6.68 x d) 1.36 x 10 9 e) 1.36 x x 10-9 g x 1 mol x 6.02 x atoms 131 g 1 mol 14. How many moles of sulfur atoms are in g of Al 2 (SO 4 ) 3? (Atomic weights: Al = 26.98, O = 16.00, S = 32.06) a) b) c) d) e) Fw Al 2 (SO 4 ) 3 = g of Al 2 (SO 4 ) 3 x 1 mol x 3 S atoms g 1 mol Al 2 (SO 4 ) 3 3

4 15. When marijuana passes through the human body, one of the products formed contains 76.4% C, 9.2% H and 14.5% O. What is the empirical formula of the compound? (Atomic weights: C = 12.01, H = 1.008, O = 16.00) a) CHO b) CH 4 O c) C 5 H 8 O d) C 7 H 10 O e) C 8 H 12 O 2 C 76.4g x 1 mol = mol = g H 9.2g x 1 mol = 9.13 mol 9.13 = g O 14.5g x 1mol = mol = g Which of the following setups is correct to calculate the number of grams of KClO 3 produced from the reaction of moles of Cl 2. (Atomic weights: K = 39.1, Cl = 35.45, O = 16.00) 3 Cl KOH 5 KCl + KClO H 2 O a) moles Cl 2 x 1 mole KClO 3 x g 3 moles Cl 2 1 mole KClO 3 b) moles Cl 2 x 3 moles Cl 2 x g 1 mole KClO 3 1 mole KClO 3 c) moles Cl 2 x 1 mole KClO 3 x 1 mole KClO 3 3 moles Cl g d) moles Cl 2 x 3 moles Cl 2 x 1 mole KClO 3 1 mole KClO g moles Fe 2 S 3 are reacted with 2.0 moles H 2 O and 3.0 moles O 2 according to the following reaction. Which is the limiting reagent? 2 Fe 2 S H 2 O + 3 O 2 4 Fe(OH) S a) Fe 2 S 3 b) H 2 O c) O 2 d) Fe(OH) 3 e) S 1.0 mol Fe 2 S 3 = moles H 2 O = moles O 2 =

5 18. The reaction of 6.8 g of H 2 S with excess SO 2 according to the following reaction yields 8.2 g of S. What is the percent yield? (Atomic weights: H = 1.008, S = 32.06, O = 16.00) Mw H 2 S = H 2 S + SO 2 3 S + 2 H 2 O a) 85% b) 87% c) 82% d) 90% e) 78% 6.8 g H 2 S x 1 mol H 2 S x 3 mol S x g S = 9.60 g S theoretical yield g H 2 S 2 mol H 2 S 1 mol S 8.2 g S (actual yield) x 100 = 85 % 9.6 g S (theoretical yield) 19. What amount of heat energy (kj) is released in the decomposition of moles of hydrogen peroxide to water and oxygen? H = -196 kj 2 H 2 O 2 (l) 2 H 2 O (l) + O 2 (g) a) 49.0 b) 98.0 c) 19.6 d) 392 e) moles H 2 O 2 x 196 kj = 49.0 kj 2 mol H 2 O What is the density (g/l) of nitrogen at STP? (Atomic weight: N = 14.01) a) b) c) 1.25 d) e) g N 2 x 1 mol = 1.25 g/l 1 mol 22.4 L 21. Which of the following statements is NOT correct? a) Pressure is force per unit area. b) Real gases behave according to the kinetic molecule theory only at high temperatures and low pressures. c) Viscosity and surface tension of liquids depend on the strength of intermolecular forces. d) A dynamic equilibrium exists between a liquid and gas at its boiling point. e) Pressure has no effect on boiling points. FALSE 5

6 22. Which conversion of units for pressure is correct? 760 mm Hg = 760 torr = 1 atm a) 1.14 x 10 3 cm Hg = 1.50 atm b) 228 mm Hg = atm c) 430 torr = 430 cm Hg d) 152 torr = atm e) atm = 45.6 mm Hg 23. The pressure on a 14.4 L sample of oxygen at 748 mm Hg is increased to 1.31 x 10 3 mm Hg at constant temperature. What will be the new volume in L? a) 25.2 b) 17.5 c) 12.4 d) 8.22 e) 6.30 V 1 x P 1 = V 2 x P L x 748 mm Hg = V 2 x 1.31 x 10 3 mm Hg V 2 = 8.22 L 24. A 2.00 L sample of air at 23 o C is warmed to 100 o C. What is the new volume (L) if the pressure remains constant? a) 2.30 b) 3.67 c) 2.54 d) 3.33 e) 2.98 V 1 = V L = V 2 T 1 T 2 ( ) K ( ) K V 2 = 2.98 L 25. A high altitude balloon is filled with 1.41 x 10 4 L of helium at 294 K and 745 torr. What is the volume (L) of the balloon at 20 Km where the temperature is 225 K and 63.1 torr? a) 1.10 x 10 5 b) 1.27 x 10 5 c) 1.58 x 10 5 d) 1.89 x 10 5 e) 2.18 x 10 5 V 1 P 1 = V 2 P x 10 4 L x 745 torr = V 2 x 63.1 torr T 1 T K 225 K V 2 = 1.27 x 10 5 L 6

7 26. Assume g of dry ice (solid CO 2 ) is placed in an evacuated 50.0 L closed tank. What will be the pressure in the tank in atmospheres at a temperature of 45 o C? Assume that all the CO 2 has been converted into gas. (Atomic weights: C = 12.01, O = 16.00; the universal gas constant is L atm mole -1 K -1 ) a) 7.25 b) 6.10 c) 5.38 d) 10.8 e) 9.15 Mw CO 2 = PV = nrt P x 50.0 L = (453.6 g x 1 mol/ g) x L atm mole -1 K -1 x ( )K P = 5.38 atm 27. Which of the following is NOT possible? a) Water can boil at room temperature. b) The boiling of water on mountain tops is below 100 o C. c) In a pressure cooker, water boils above 100 o C. d) Water has a lower heat of vaporization than CH 4. e) Water has a higher surface tension than gasoline. 28. Which of the following molecules has the lowest boiling point? d > b > e > a > c a) CH 3 CH 2 CH 2 CH 3 b) CH 3 CH 2 CH 2 OH CH 3 c) CH 3 CH CH 3 d) HO CH 2 CH 2 OH O e) CH 3 C CH In which of the pure compounds in Question 28 would dipole-dipole forces be observed? Hydrogen-bonding possible only for b and d but molecules a) b, d and e b, d, and e are all polar and have dipole moments. b) a and c Molecules a and c are nonpolar and exhibit only London forces. c) only e d) all of them e) none of them 7

8 30. Oxygen toxicity occurs if a partial pressure of oxygen of about 1 atm is breathed for too long. At what total pressure of compressed air delivered to a diver can toxicity occur? Air is 20 % oxygen. a) 1 atm b) 2 atm c) 3 atm d) 4 atm e) 5 atm 0.20 x (? atm compressed air) = 1 atm O 2? atm compressed air = 5 atm Solubility Rules of Common Ionic Compounds 1. All ionic compounds of lithium, sodium, potassium, rubidium, cesium, and ammonium ions are soluble. 2. All nitrates, chlorates, and perchlorates are soluble. 3. The chlorides, bromides, and iodides of most metals are soluble. Principal exceptions are those of lead, silver, and mercury (I). 4. All sulfates are soluble except those of strontium, barium, lead, and mercury (I). 5. All carbonates, chromates, and phosphates are insoluble except those of lithium, sodium, potassium, rubidium, cesium, and ammonium. 6. The hydroxides of lithium, sodium, potassium, rubidium, and cesium ions are soluble. The hydroxides of calcium, strontium, and barium are moderately soluble. The rest of the hydroxides are insoluble. 7. The sulfides of all metals are insoluble except those of lithium, sodium, potassium, rubidium, cesium, and ammonium. 8