May 2, 201212. The only stable isotopes of carbon are C-12 and C-13. Predict the mode of decay of C.17. The heaviest known isotope of hydrogen is called tritium, H. It decays by beta emission, and has a half-life of 12.3 years. What fraction of a tritium sample will remain after 20.0 years ?18. The radioisotope potassium-40 decays to argon-40 by positron emission with a half-life of 1.3 ´ 109 yr. What would the atom ratio of 40Ar to 40K be in a rock that is 5.0 ´ 108 years old? (You may assume that there was no 40Ar in the rock when it was formed.) A. 0.31 B. 0.70 C. 1.2 D. 1.9 E. 2.819. Calculate the energy released in kJ/mole by the following fusion reaction: H + H HeCHEM 188 – Spring, 2012Hour Exam 4 (Early)May 2, 2012Instructions:Your scantron answer sheet must show your NAME, 7-DIGIT KU ID NUMBER, and LAB SECTION. (Begin these entries at the LEFT end of the space provided.) In answering the questions, be careful to fill in the corresponding circles on the answer sheet according to the number of the question on the exam. USE A SOFT (No. 2) PENCIL. Note that a periodic table of the elements is attached at the end of the exam.Useful information: Avogadro's Number NA = 6.022 × 10 23 mol1Gas constant R = 8.314 JK1mol1 = 0.0821 LatmK1mol1Boltzmann constant k = 1.38 × 1023 JK1Planck’s constant h = 6.626  1034 JsSpeed of light c = 3.00  108 ms1 Conversion factors: 1 atm = 760 mm Hg 1 Latm = 101.3 J 1 amu = 1.66 × 1027 kg 1 watt = 1 J/s Gibbs Free Energy G = Go + RT ln Q First-order kinetics N = Noexp(t)1. Calculate G at 298 K for the reaction N2O4(g)  2NO2(g)given that Gf [N2O4(g)] = 98.3 kJ/mol and Gf [NO2(g)] = 51.8 kJ/mol at 298K. A. 46.5 kJ B. 5.3 kJ C. 0 kJ D. 5.3 kJ E. 46.5 kJ2. Given the following data at 25oC, C(graphite) + O2(g)  CO2(g) Go = 394.4 kJ/mole CO(g) + ½ O2(g)  CO2(g) Go = 257.1 kJ/molededuce the standard free energy of formation, Gfo, of CO(g) at 25oC.A. –257.1 kJ/mole B. –137.3 kJ/mole C. 0 kJ/mole D. 137.3 kJ/mole E. 257.1 kJ/mole13. For the reaction BaO(s) + CO2(g)  BaCO3(s) H = 267.1 kJ and S = 171.8 J/K at 25C. Estimate the minimum temperature at which this reaction will be spontaneous under standard state conditions. A. 0 K B. 273 K C. 838 K D. 1555 K E. 1711 K4. For the reaction 2C(graphite) + H2(g)  C2H2(g), G= +209.2 kJ/mol at 25C. If P(H2) = 100. atm, and P(C2H2) = 0.10 atm, calculate G for this reaction at this temperature.A. +207.8 kJ/mol B. +226.3 kJ/mol C. +192.1 kJ/mol D. +17.3 kJ/mol E. 16.9 kJ/mol5. A saturated solution of magnesium hydroxide was found to have a pH of 10.46 at 25oC. What is the value of Go (in kJ/mol) at 25oC for the reactionMg(OH)2(s)  Mg2+(aq) + 2OH(aq)A. 29 B. 62 C. 79 D. 110 E. 1906. Hydrogen peroxide (H2O2) decomposes according to the equation H2O2(l)  H2O(l) + ½O2(g).Estimate Kp for this reaction at 0C. You may assume that H = 98.2 kJ/mol and S = 70.1 J/K·mol at this temperature.A. 3.6  1026B. 2.9  1020C. 3.5  1019D. 7.5  1020E. 2.8  10227. How many neutrons and protons (nucleons) does an atom with the symbol P have?A. 15 B. 16 C. 31 D. 46 E. None of these 8. The symbol for an electron is A. n B.  C.  D. He E. 11H9. As a result of alpha decay, the product nucleus is2A. one atomic number lower than the original element.B. two atomic numbers higher than the original element.C. one atomic number higher than the original element.D. two atomic numbers lower than the original element.E. four atomic numbers lower than the original element.10. A radioisotope decays to give a beta particle and Nb-97. What was the original element?A. Y B. Zr C. Mo D. Ru E. none of these11. A typical atomic nucleus has a mass of about A. 1  1014 g B. 1  1018 g C. 1  1022 g D. 1  1026 g E. 1  1030 g12. The only stable isotopes of carbon are C-12 and C-13. Predict the mode of decay of 6 11C. A. alpha emission B. beta emission C. proton emission D. neutron emissionE. positron emission13. Which of the following nuclides has the highest nuclear binding energy per nucleon?A. H B. He C. C D. 8 16O E. 1735Cl14. What is the nuclear binding energy per nucleon for 37Li (atomic mass 7.016005 amu). Data: H (atomic mass) = 1.007825 amu; n (mass) = 1.008665 amu; 1 kg = 6.022 ´ 1026 amu; c= 3.00 ´ 108 m/s.A. 4.04  1013 J /nucleonB. 8.55 ´ 1013 J/nucleonC. 8.99 ´ 1013 J/nucleonD. 1.04  1012 J/nucleonE. 6.29  1012 J/nucleon15. In the Th decay series there are six radioisotopes that decay by alpha emission, including Th-232 itself, and four radioisotopes that decay by beta emission. The final product of this series is a stable isotope. The symbol for this product isA. W B. W C. Pb D. Pb E. Pt16. Calculate the energy released in MeV (1 MeV = 1.6022 × 10-13 joules) when one atom of Li-10 decays according to the reaction33 10Li  39Li + 0 1 n Atomic masses: Li-10 = 10.035481 amu, Li-9 = 9.026790 amu, n = 1.008665 amu.A. -0.35 MeV B. 0.02 MeV C. 1.32 MeV D. 13.1 MeV E. 20.1 MeV17. The heaviest known isotope of hydrogen is called tritium, H. It decays by beta emission, and has a half-life of 12.3 years. What fraction of a tritium sample will remain after 20.0 years ? A. 0.034 B. 0.105 C. 0.184 D. 0.245 E. 0.32418. The radioisotope potassium-40 decays to argon-40 by positron emission with a half-life of 1.3 ´ 109 yr. What would the atom ratio of 40Ar to 40K be in a rock that is 5.0 ´ 108 years old? (You may assume that there was no 40Ar in the rock when it was formed.)A. 0.31 B. 0.70 C. 1.2 D. 1.9 E. 2.819. Calculate the energy released in kJ/mole by the following fusion reaction:11H + 12H  23He Atomic masses: H-1 = 1.007825 amu, H-2 = 2.014102 amu, He-3 = 3.016029 amu.A. 3.91 ´ 108 kJ/mole B. 5.29 ´ 108 kJ/mole C. 1.24 ´ 108 kJ/mole D. 1.70 ´ 108 kJ/mole E. 2.16 ´ 109 kJ/mole20. Which one of the following is not one of the five gaseous components in highest concentration in the atmosphere?A. CH4 B. CO2 C. N2D. Ar E. O221. The lowermost layer of the atmosphere is