Chemistry 122 Wrap-Up Review Kundell

Chapter 11 Chemistry 122 Wrap-Up Review Kundell 1. The enthalpy (heat) of vaporization for ethanol (C 2 H 5 OH) is 43.3 kj/mol. How much heat, in kilojoules, is required to vaporize 115 g of ethanol at 25 C? a) 4.98 10 3 b) 108 c) 17.4 d) 650 e) 43.3 2. Which of the following compounds is predicted to have the highest vapor pressure at STP? a) H 2 O b) CH 4 c) CH 3 OH d) C 6 H 5 NH 2 e) C 6 H 12 O 6 3. Which of the following compounds is predicted to have the highest boiling point? a) CH 3 OH b) H 2 O c) CH 2 Cl 2 d) CH 3 OCH 3 e) CH 4 4. In which substance would the dispersion forces be greatest? a) H 2 b) F 2 c) Cl 2 d) Br 2 e) I 2 5. Which of the following substances would exhibit dipole-dipole intermolecular forces? a) BCl 2 b) CF 4 c) CO 2 d) Cl 2 e) NH 3 6. The boiling points of the noble gases increase going down the group. What type of intermolecular force best accounts for this fact? a) permanent dipole b) ion-ion c) hydrogen bonding d) London dispersion e) ion-dipole 7. Which of the following substances is a liquid at STP? a) CH 3 CH 3 b) Cl 2 c) H 2 S d) CH 3 OH e) CH 4

Chapter 12 1. What is the total number of moles of ions in 0.250 L of 0.391 M Na 2 CO 3? a) 0.391 b) 0.0978 c) 0.293 d) 0.196 e) 0.587 2. What is the mass percent concentration of a solution containing 6.00 ml ethanol (d = 0.789 g/ml) in 60.0 g water? a) 6.00 b) 7.60 c) 7.31 d) 11.2 e) 10.0 3. What mass, in g, of NaOH (FW = 40.01) is present in 2.30 L of 5.40 m NaOH? (d = 1.15 g/ml) a) 497 b) 216 c) 571 d) 516 e) 470 4. Calculate the molality of methanol in a solution prepared by dissolving 75.0 ml methanol, CH 3 OH, (d = 0.791 g/ml) in 150 g ethanol. a) 19.8 b) 0.0156 c) 15.6 d) 0.0123 e) 12.3 5. What is the mole fraction of biphenyl, C 12 H 10, in a solution prepared by dissolving 22.5 g C 12 H 10 (s) in 285 g of benzene, C 6 H 6 (l)? a) 0.0732 b) 0.0384 c) 0.0400 d) 0.50 e) 0.0789 6. Which of the following concentration units is independent of temperature? a) molarity b) molality c) volume percent d) mass/volume percent e) None of the above units are independent of temperature

7. The solubility of O 2 (g), in water at 25 C is 3.16 ml/100 g H 2 O when the gas pressure is maintained at 1 atm. What pressure of O 2 (g) would be required to produce a saturated solution containing 10.9 ml/100 g H 2 O? a) 4.45 b) 3.45 c) 0.290 d) 3.16 e) 10.9 8. The vapor pressure of pure benzene (C 6 H 6 ) and toluene (C 7 H 8 ) at 25 C are 95.1 and 28.4 mm Hg respectively. A solution is prepared with a mole fraction of toluene of 0.750. Assume the solution to be ideal and determine the total vapor pressure above the solution, in mm Hg. a) 61.8 b) 66.7 c) 123.5 d) 45.1 e) 78.4 9. Calculate the vapor pressure, in mm Hg, at 25 C of water above a solution made by dissolving 100. g sucrose, C 12 H 22 O 11 (FW = 342.3) in 250. g of water. The vapor pressure of pure water at 25 C is 23.8 mm Hg. a) 23.8 b) 14.3 c) 23.3 d) 9.52 e) 0.501 10. What is the freezing point of an aqueous glucose solution that has 25.0 g of glucose, C 6 H 12 O 6 per 100.0 g H 2 O? (K f = 1.86 C m 1 ) a) -2.58 b) -0.258 c) -0.138 d) 0.258 e) -1.38 11. A 0.750 g sample of an unknown substance is dissolved in 20.0 g of benzene; the freezing point of the solution is 4.53 C. Calculate the molar mass of the substance. The normal freezing point for benzene is 5.53 C and K f is 5.12 C m 1. a) 180 b) 870 c) 7.32 d) 192 e) 341 12. Which solution has the highest boiling point? a) 0.1 m urea b) 0.06 m HCl c) 0.05 m CaCl 2 d) 0.04 m (NH 4 ) 3 PO 4 e) 0.07 m NaCl

13. What would be the osmotic pressure, in atm, produced by a 0.300 M solution of sucrose, C 12 H 22 O 11 (FW = 342.3) at 25 C? a) 0.131 b) 102 c) 330 d) 7.34 e) 0.615 14. Which aqueous solution has the greatest osmotic pressure? a) 10.0 g urea, CO(NH 2 ) 2, in 1.00 L at 298 K b) 10.0 g urea in 1.00 L at 303 K c) 10.0 g urea in 0.500 L at 298 K d) 5.0 g urea in 1.00 L at 293 K e) 5.0 g urea in 0.500 L at 298 K Chapter 13 (Also be able to do initial rates problems!) 1. In the reaction, A Products, the initial concentration of A is 1.60 M, and 45 s later it is 1.20 M. What is the initial rate of this reaction in M s 1? a) 8.0 10 3 b) 3.1 10 2 c) 8.9 10 3 d) 2.7 10 2 e) 3.5 10 2 2. In the reaction A + 3B C + 2D, the rate of reaction of A is found to be 1.5 10 1 M s 1. What is the rate of reaction of B? a) 5.0 10 2 b) 1.5 10 1 c) 3.0 10 1 d) 4.5 10 1 e) 6.0 10 1 3. The half-life of the first order reaction A B is 5.0 min. How many minutes will it take to reduce the concentration of A to 1/16 of the initial value? a) 5.0 b) 10. c) 20. d) 25 e) 80. 4. A sample of radioactive radon-222 was found to have a half-life of 3.823 d. What fraction of the sample will still be radon-222 after 1 week? Assume radioactive decay to follow first-order kinetics. a) 7% b) 14% c) 18% d) 28% e) Not enough information is given to answer this question.

5. In the first order reaction, A Products, the initial concentration of A is 1.56 M and 0.869 M after 48.0 minutes. What is the half-life of the reaction, in min? a) 72.8 b) 36.2 c) 56.9 d) 63.9 e) 41.0 6. For first order reactions the slope of a plot of ln [A] vs. time is a) k. b) -k. c) kt. d) k/t. e) k ln [A]0. 7. Consider the following 2-step mechanism. Which of the species in the mechanism is the catalyst? H 2 O 2 + I H 2 O + OI fast step H 2 O 2 + OI H 2 O + O 2 + I slow step ------------------------------------- 2 H 2 O 2 2 H 2 O+ O 2 net reaction a) H 2 O 2 b) H 2 O c) I d) OI e) O 2 8. Consider the following 2-step mechanism. What is the overall rate equation for the net reaction? H 2 O 2 + I H 2 O + OI fast step H 2 O 2 + OI H 2 O + O 2 + I slow step ----------------------------------- 2 H 2 O 2 2 H 2 O+ O 2 net reaction a) Rate = k [H 2 O 2 ] [OI ] b) Rate = k [H 2 O 2 ] [I ] c) Rate = k [H 2 O] [OI ] d) Rate = k H 2 O 2 e) Rate = k [H 2 O 2 ] [O 2 ] 9. What is the rate law for the reaction of hydrogen gas and chlorine gas to form HCl? a) rate = k [H 2 ] [Cl2] b) rate = k [H 2 ] c) rate = k [H 2 ]2 [Cl 2 ]2 d) rate = k [H] [Cl] e) The rate law cannot be determined without experimentation.

10. Consider the following hypothetical reaction: A C + D The rate of the reaction doubles when the concentration of A doubles. What will happen to the rate of the reaction if the concentration of A is quadrupled? a) The rate doubles. b) The rate triples. c) The rate quadruples. d) The rate is halved. e) The rate stays constant. 11. The half-life of a first order reaction is 3.00 hours. How long will it take for 33.4% of the starting materials to react? a) 4.75 b) 15.2 c) 3.29 d) 0.366 e) 7.75 Chapter 14 1. The value of K c is changed when a) the concentration of reactants are changed. b) the volume of the system is changed. c) the pressure of the system is changed. d) the temperature of the system is changed. e) a catalyst is added. 2. If the equilibrium concentrations found in the reaction: 2 A (g) + B (g) 2 C (g), are [A] = 0.30 M, [B] = 0.10 M, and [C] = 0.20 M, calculate the value of K c. a) 0.23 b) 4.4 c) 6.7 d) 3.3 e) 0.21 3. The value of K p for the reaction 2 NO 2 (g) N 2 O 4 (g) is 1.52 at 319 K. What is the value of K p at this temperature for the reaction 1/2 N 2 O 4 (g) NO 2 (g)? a) 0.76 b) -0.76 c) 0.811 d) 1.23 e) 0.58

4. For which of the following values of K c will the equilibrium mixture consist almost entirely of reactants? a) 0.030 b) 1.00 c) 1 10 10 d) 30 e) 4 10 8 5. For the system CaO (s) + CO 2 (g) CaCO 3 (s), the equilibrium constant expression is a) [CaCO 3 ] / [CaO] [CO] b) 1/ [CaO] [CO] c) [CO 2 ] d) CaO [CO 2 ] / [CaCO 3 ] e) 1/ [CO 2 ] 6. Which change will increase the quantity of product in the following reaction? a) an increase in temperature b) a decrease in volume of container c) a decrease in pressure d) adding a catalyst e) increasing P by adding some argon 2 SO 2 (g) + O 2 (g) 2 SO 3 (g) ΔH = -198 kj 7. At a particular temperature, K c = 54 for the reaction H 2 (g) + I 2 (g) 2 HI (g). If 1 mole of H 2 and 1 mole of I 2 are placed in a 5.0 L container, what would be the equilibrium concentration of HI? a) 0.16 b) 0.04 c) 0.32 d) 0.08 e) 0.20 8. Consider the following equilibrium: PCl 5 (g) PCl 3 (g) + Cl 2 (g) 5.0 moles of PCl 5 are placed in a 10.0 L flask at 200 C and allowed to come to equilibrium. Analysis shows that 1.0 mole of Cl 2 is present in the equilibrium mixture. How many moles of PCl 5 are present at equilibrium. a) 0 b) 1.0 c) 2.0 d) 3.0 e) 4.0

9. For the reaction: CO (g) + H 2 O (g) CO 2 (g) + H 2 (g) K c = 23.2 at 600 K If a 0.250 mol sample of CO (g) and a 0.250 mol sample of H 2 O (g) are introduced into a 2.00 L 600 K, what is the concentration of CO (g) at equilibrium? a) 0.207 M b) 0.104 M c) 0.414 M d) 0.043 M e) 5.80 M vessel at Chapter 15 1. Which is the weakest acid? a) HOCl b) HOClO c) HOClO 2 d) HOClO 3 2. The ph of acid rain may be as low as 2.80. What is the [H 3 O + ] in such acidic rain? a) 1.6 b) 9.7 10 2 c) 6.3 10 12 d) 1.6 10 3 e) 630 3. Calculate the ph of a 0.0015 M HCl solution. a) 2.82 b) 1.5 c) 11.17 d) 3.84 e) 1.5 10-3 4. A sample of milk is found to have a ph of 6.25. What is the [OH ] in this milk? a) 5.6 10 7 b) 1.00 10 14 c) 7.75 d) 1.8 10 6 e) 1.8 10 8 5. A ph meter reads 4.48. What is the [H 3 O + ] in the solution? a) 3.0 10 4 b) 3.3 10 5 c) 9.52 d) 7.00 e) 3.0 10 10 6. Calculate the poh of a 3.5 10 2 M NaOH solution. a) 11.46 b) 12.54 c) 2.46 d) 1.46 e) 0.46

7. The ph of a 0.30 M solution of HCN is 5.20. Calculate the K a value for HCN. a) 6.3 10 6 b) 1.3 10 10 c) 4.8 10 2 d) 2.1 10 5 e) 8.4 10 18 8. The ph of a 0.24 M solution of dimethylamine is 12.01. Calculate the K b value for dimethylamine. a) 0.24 b) 0.18 c) 4.3 10 2 d) 4.4 10 4 e) none of these 9. What is K b for an acid whose K a = 0.000051? a) 2.0 x 10-10 b) 2.0 x 104 c) 5.1 x 10-5 d) 3.9 x 104 e) 2.0 x 10-3 10. Which one of the following salts will have a water solution with a ph less than 7? a) NH 4 Cl b) NaBr c) K 2 CO 3 d) KCN e) NaC 2 H 3 O 2 11. The ph of a 0.25 M NaCN solution is 11.40. Calculate the pk b value for CN. a) 1.25 b) 4.60 c) 2.60 d) 5.85 e) 11.40 12. Calculate the ph of 0.50 M NaCN. (K a (HCN) = 6.2 10 10 ) a) 11.45 b) 9.51 c) 4.49 d) 9.21 e) 2.55 13. Calculate the ph of a solution that is both 0.50 M CH 3 COOH and 0.50 M CH 3 COONa. (K a CH 3 COOH = 1.8 10 5 ) a) 4.74 b) 9.26 c) 2.52 d) 11.48 e) 7.00

14. What must be the concentration of CH 3 COO ion in 0.40 M CH 3 COOH to produce a buffer solution with ph = 4.80? (K a CH 3 COOH = 1.8 10 5 ) a) 1.6 10 5 b) 0.46 c) 2.7 10 3 d) 4.74 e) 0.40 15. Calculate the ph after 10.0 ml of 0.40 M NaOH is added to 20.0 ml of 0.50 M HCl. a) 0.30 b) 0.70 c) 13.30 d) 13.70 e) 7.00 16. What is [OH-], if the ph = 9.0? a) 1.00 x 10-5 b) 1.00 x 10-9 c) 5.0 d) -9.54 x 10-1 e) 1.30 x 101 17. What is the ph of a solution that is 0.80 M CH 3 COONa? K a = 1.8 10-5 a) 18.7 b) 4.67 c) 24.8 d) 2.42 e) 16.4 Chapter 16 1. What is the K sp expression for magnesium phosphate, Mg 3 (PO 4 ) 2? a) K sp = [Mg 2+ ] [PO 4 3 ] b) K sp = [Mg 2 + ] 2 [PO 4 3 ] 3 c) K sp = [Mg 2 + ] 3 [PO 4 3 ] d) K sp = [Mg 2 + ] 3 [PO 4 3 ] 2 / [Mg 3 (PO 4 ) 2 e) K sp = [Mg 2+ ] 3 [PO 4 3 ] 2 2. The solubility of silver carbonate is 0.032 M at 20 C. Calculate the K sp of silver carbonate. a) 3.3 10 5 b) 1.0 10 3 c) 5.0 10 4 d) 1.3 10 4 e) 6.5 10 5 3. Calculate the molar solubility of PbI 2. (K sp = 7.1 10 9 ) a) 1.9 10 3 b) 1.5 10 3 c) 8.4 10 5 d) 4.8 10 3 e) 1.2 10 3

4. Consider saturated solutions of the following compounds. Which solution has the highest concentration of F ion? a) BaF 2 1.3 10 6 b) CaF 2 3.9 10 11 c) MgF 2 3.7 10 8 d) PbF 2 3.6 10 8 e) SrF 2 7.9 10 10 5. Calculate the molar solubility of Al(OH) 3. (K sp = 1.3 10 33 ) a) 1.8 10 17 b) 4.8 10 35 c) 6.0 10 9 d) 1.3 10 33 e) 2.6 10 9 6. Which would precipitate first upon addition of the sodium salts of the following anions to solutions 0.10 M in Pb(NO 3 )? K sp of lead salt a) C 2 H 3 O 2 1.8 10 3 b) Br 4.0 10 5 c) Cl 1.6 10 5 d) OH 1.2 10 15 e) IO 3 3.2 10 13 7. Will a precipitate be observed if 0.10 mol Ag + and 0.001 mol SO 4 2 are added to make 1.0 L of solution? (K sp = 1.4 10 5 ) a) Yes, because Q > K sp. b) Yes, because Q < K sp. c) No, because Q > K sp. d) No, because Q < K sp. e) More information is needed to answer this question. Chapter 17 1. For which of the following reactions would you expect the entropy change to be closest to zero? a) 2 H 2 (g) + O 2 (g) H 2 O (l) b) N 2 (g) + O 2 (g) 2 NO (g) c) 2 NO (g) + O 2 (g) 2 NO 2 (g) d) Zn (s) + 2 H + (aq) Zn 2+ (aq) + H 2 (g) e) 2 HgO (s) 2 Hg (l) + O 2 (g) 2. For which of the following processes will ΔS system be the most positive? a) 2 NH 3 (g) N 2 (g) + 3 H 2 (g) b) Hg (l) Hg (s) c) C 2 H 2 (g) + H 2 (g) C 2 H 4 (g) d) 4 Fe (s) + 3 O 2 (g) 2 Fe 2 O 3 (s) e) 2 SO 2 (g) + O 2 (g) 2 SO 3 (g)

3. Given the following standard molar entropies, calculate ΔS (in J/K) for the reaction: C (s) + O 2 (g) CO 2 (g) S J/mol K 5.74 205.0 213.6 a) -2.86 b) 424.3 c) -424.3 d) 2.86 e) none of these 4. Consider the following reaction: PCl 5 (g) PCl 3 (g) + Cl 2 (g). ΔH = +87.9 kj/mol and ΔS = +170.2 J/mol K. At what temperature, in C, does the reaction become spontaneous? a) 25 b) 343 c) 243 d) 616 e) 516 5. Which of the following is most dependent on temperature? a) ΔH b) ΔS c) ΔG d) None of the above depends on temperature. 6. Predict the signs of ΔS, ΔH, and ΔG for the following process (at 25 C): a) ΔS ΔH ΔG + + - 2 H 2 O (l) 2 H 2 (g) + O 2 (g) b) ΔS ΔH ΔG + - - c) ΔS ΔH ΔG + + + d) ΔS ΔH ΔG - - - e) ΔS ΔH ΔG - + + 7. Consider the following data and calculate ΔG, in kj, for the following reaction at 25 C. 2 O 3 (g) 3 O 2 (g) ΔG f kj/mol 163.2 0 a) -326.4 b) 163.2 c) 326.4 d) 489.6 e) -163.2

8. Consider the following data and calculate ΔG, in kj, at 155 C for the following reaction. 2 O 3 (g) 3 O 2 (g) ΔH f kj/mol 142.7 0 S J/mol K 238.8 205.0 a) -5.91 10 4 b) -2.16 10 4 c) -344.2 d) -306.7 e) none of these 9. The standard free energy of formation of water is -237.18 kj/mol. Determine the value of K eq at 25 C for the reaction: 2 H 2 (g) + O 2 (g) 2 H 2 O (l). a) 3.62 10-42 b) 2.77 c) 5.28 d) 0.826 e) 1.41 10 83 10. Calculate the ΔG, in kj, for the reaction at 25 C if the value of K eq is 0.144. a) 4.80 b) 0.403 c) 47.4 d) -4.80 e) -0.403 N 2 O 4 (g) 2 NO 2 (g) 11. Which of the following must be true in order for a reaction to be at equilibrium? a) ΔS = 0 b) ΔH = 0 c) ΔG = 0 d) T = 298 K e) K eq = 0 Chapter 18 1. How many electrons are transferred in the following reaction? a) 1 b) 2 c) 3 d) 6 e) 14 6 Br - (aq) + Cr 2 O 7 2- (aq) + 14 H + (aq) 2 Cr 3+ (aq) + 7 H 2 O + 3 Br 2 (l)

2. Balance the following half-reaction under basic conditions and indicate the coefficient of water and the side of the reaction to which it is added. a) 4, left b) 1, right c) 2, left d) 2, right e) 3, left HCHO + MnO 2 (s) MnO 4 + CH 3 OH 3. When the following half-reaction is balanced, the number of electrons and the type of process (oxidation or reduction) is MnO 4 (aq) Mn 2+ (aq) a) 1, oxidation. b) 1, reduction. c) 3, oxidation. d) 5, oxidation. e) 5, reduction. Table 18.1 Selected Standard Electrode Potentials at 25 C Reaction E, V Mg 2+ (aq) + 2e Mg (s) -2.356 Fe 2+ (aq) + 2e Fe (s) -0.440 Pb 2+ (aq) + 2e Pb (s) -0.125 2 H + (aq) + 2e H 2 (g) 0.0 Cu 2+ (aq) + 2e Cu (s) +0.337 I 2 (s) + 2e 2 I (s) +0.535 Fe 3+ (aq) + 2e Fe 2+ (aq) +0.771 Ag + (aq) + e Ag (s) +0.800 O 2 (g) + 4 H + (aq) + 2e 2 H 2 O +1.229 Cl 2 (g) + 2e 2 Cl (aq) +1.358 F 2 (g) + 2e 2 F (aq) +2.866 4. (Refer to Table 18.1) Which is the best oxidizing agent? a) F b) Mg 2+ c) Fe 3+ d) Cu 2+ e) Cl 2 5. (Refer to Table 18.1) Which is the best reducing agent? a) F b) Ag c) Pb d) Fe 2+ e) Mg 6. (Refer to Table 18.1) Which is the most easily oxidized? a) Fe b) Mg c) H + d) Cu e) Cl

7. (Refer to Table 18.1) Which is the most easily reduced? a) Mg 2+ b) H + c) Cu d) Cl e) Cl 2 8. (Refer to Table 18.1) How many metals listed will react with aq HCl with evolution of hydrogen gas? a) 0 b) 1 c) 2 d) 3 e) 4 9. (Refer to Table 18.1) How many of the metal ions listed will lead displace from aqueous solutions? a) 0 b) 1 c) 2 d) 3 e) 4 10. (Refer to Table 18.1) Will magnesium metal displace Cu 2+ ion from aqueous solution? a) yes b) no c) impossible to tell 11. (Refer to Table 18.1) Will iron metal displace Mg 2+ ion from aqueous solution? a) yes b) no c) impossible to tell

12. (Refer to Table 18.1) Will the following reaction occur spontaneously as written? a) yes b) no c) impossible to tell Cl 2 (g) + Fe (s) 2 Cl (aq) + Fe 2+ (aq) 13. (Refer to Table 18.1) Will the following reaction occur spontaneously as written? a) yes b) no c) impossible to tell 2 I 2 (s) + 2 H 2 O 4 I (aq) + O 2 (g) + 4 H + (aq) 14. (Refer to Table 18.1) Calculate the value of G for the following reaction, in kj. a) +145 b) -145 c) 150 d) +291 e) -291 Cl 2 (g) + 2 F (aq) 2 Cl (aq) + F 2 (g) 15. (Refer to Table 18.1) Calculate the value of K eq at 25 C for the reaction: a) 60.5 b) 1.8 10 26 c) 1.1 d) 7.41 10 14 e) 1.35 10 13 Cu 2+ (aq) + Fe (s) Cu (s) + Fe 2+ (aq) 16. Cu metal displaces Ag + (aq) from an aqueous solution. Which of the following is correct? a) Ag is easier to oxidize than Cu. b) Ag + is easier to reduce than Cu 2+. c) Ag is a better reducing agent than Cu. d) Cu 2+ is a better oxidizing agent than Ag +. 17. Use the Nernst equation to determine E cell at 25 C for the following voltaic cell. (E cell = +1.100V) Zn (s) / Zn 2+ (0.10 M) // Cu 2+ (1.0 M) / Cu (s) a) 1.17 b) 1.16 c) 1.10 d) 1.07 e) 1.04

18. For how many minutes must the electrolysis of a solution containing Au 3+ (aq) be carried out with a current of 3.55 A to deposit 1.00 g Au at the cathode? a) 2.30 b) 6.90 c) 20.7 d) 29.0 e) 414 19. How many grams of silver are deposited from a solution of Ag + on a tin cathode in 1.25 h by a current of 3.50 A? a) 8.80 b) 0.163 c) 17.6 d) 0.293 e) 438 Chapter 19 1. What is the product formed from 232 Th by α-particle emission? a) 228 Th b) 232 Ac c) 232 Ra d) 228 Ra e) 228 Ac 2. What is the product formed from 185 Ir by electron capture? a) 184 Os b) 185 Pt c) 185 Os d) 184 Os e) 186 Ir 3. When 9 Be is bombarded with α-particles, 14 C is formed. What other particle is produced? a) β - b) β + c) n d) ρ + e) α 4. The half-life of sodium-24 is 15.0 h. How many hours will it take for an initially observed activity to decrease to 75% of its initial value? a) 5.0 b) 6.2 c) 7.5 d) 11.3 e) 30 5. It has taken 19 days for a particular nuclide to decay to 50% of its original activity. What is the half-life of this nuclide? a) 9.5 days b) 19 days c) 38 days d) 28.5 days e) More information is needed to solve this problem.

6. In a nuclear reaction, the mass lost in the reaction must be replaced by a) mass gained in the products. b) potential energy of the reactants. c) kinetic energy of the reactants. d) the speed of light of the universe. e) kinetic energy of the products. 7. How much energy, in kilojoules, would be produced in a nuclear reaction in which 0.0015 g of material is converted entirely into energy? a) 1.4 10 11 kj b) 1.4 10 14 kj c) 450 kj d) 1.4 10 8 kj e) 1.7 10-20 kj 8. Why is α-particle emission less hazardous than γ-ray or X-ray emission? a) Less α-particle emission occurs naturally than γ-ray or X-ray emission. b) α-particles are very high in energy and can pass through living tissue without harming it. c) γ-rays and X-rays are hazardous because the rays are highly penetrating, causing damage inside the body quite easily. d) α-particles are less hazardous because they are electrons, while γ-rays and X-rays have much more mass. e) None of these are hazardous to living creatures-β-particles are hazardous. 9. What is the identity of the missing species in the following reaction? a) 17O b) 17N c) 19O d) 19F e) 18O 14N + 4He 1H +??? 10. What would be the atomic number of an element that would result from positron emission from a) 28 b) 30 c) 29 d) 25 e) 43 45 X 29