3. The partial pressures of CH₄, N₂, and O₂ in a sample of gas were found to be 135 mm-Hg, 508 mm-Hg, and 571 mm-Hg, respectively. Calculate the mole fraction of nitrogen.
(A) 20.4；
(B) 0.470；
(C) 0.418；
(D) 0.751；
(E) 0.359

79. 梁女士產後第2天，詢問新生兒沐浴的相關事項，下列回應何者錯誤？(A)幫新生兒洗澡是親子社交 的良好時機 (B)應在溫暖的房間為新生兒洗澡，以減少新生兒體熱散失 (C)可使用無香料肥皂輕柔 的洗淨，避免新生兒皮膚損傷 (D)眼睛由外向內清洗

80. 產後評估深層靜脈血栓，進行伸直腿且足板背側彎曲的試驗稱為：(A)希氏試驗（Schultze test） (B)霍曼氏試驗（Homan’s test）(C)畢夏氏試驗（Bishop’s test）(D)貝拉德試驗（Ballard test）

1. A 0.4987 g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.9267 g of CO2 and 0.1897 g of H2O. What is the empirical formula of the compound? (A) CHO； (B) C2H2O； (C) C3H3O2； (D) C6H3O2； (E) C3H6O2

2. A 0.307 g sample of an unknown triprotic acid is titrated to the third equivalence point using 35.2 mL of 0.106 M NaOH. Calculate the molar mass of the acid. (Na: 22.99 g/mol) (A) 247 g/mol； (B) 171 g/mol； (C) 165 g/mol； (D) 151 g/mol； (E) 82.7 g/mol

4. A 32.5 g piece of aluminum (which has a molar heat capacity of 24.03 J/°C·mol) is heated to 82.4°C and dropped into a calorimeter containing water (specific heat capacity of water is 4.18 J/g°C) initially at 22.3°C. The final temperature of the water is 24.2°C. Ignoring significant figures, calculate the mass of water in the calorimeter. (Al: 26.98 g/mol) (A) 212 g； (B) 5.72 kg； (C) 6.42 g； (D) 1.68 kg； (E) none of these

5. Which of the following statements is (are) true? I. An excited atom can return to its ground state by absorbing electromagnetic radiation. II. The energy of an atom is increased when electromagnetic radiation is emitted from it. III. The energy of electromagnetic radiation increases as its frequency increases. IV. An electron in the n = 4 state in the hydrogen atom can go to the n = 2 state by emitting electromagnetic radiation at the appropriate frequency. V. The frequency and wavelength of electromagnetic radiation are inversely proportional to each other.(A) II, III, IV； (B) III, V； (C) I, II, III； (D) III, IV, V； (E) I, II, IV

6. Consider the following reaction: A2 + B2  2AB ∆H = -365 kJ The bond energy for A2 is half the amount of AB. The bond energy of B2 = 447 kJ/mol. What is the bond energy of A2? (A) 812 kJ/mol； (B) 630 kJ/mol； (C) 271 kJ/mol； (D) –183 kJ/mol； (E) none of these

7. Consider the molecular orbital energy level diagrams for O2 and NO. Which of the following is true? I. Both molecules are paramagnetic. II. The bond strength of O2 is greater than the bond strength of NO. III. NO is an example of a homonuclear diatomic molecule. IV. The ionization energy of NO is smaller than the ionization energy of NO+. (A) I only； (B) I and II； (C) I and IV； (D) II and III； (E) I, II, and IV

8 If equal, rigid spheres are arranged in a simple cubic lattice in the usual way (i.e., in such a way that they touch each other), what fraction of the corresponding solid will be empty space? (A) 0.52； (B) 0.32； (C) 0.68； (D) 0.48； (E) none of these

9 At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene (vapor pressure of pure toluene = 290 torr). The mole fraction of benzene in the vapor above the solution is 0.590. Assuming ideal behavior, calculate the mole fraction of toluene in the solution. (A) 0.213； (B) 0.778； (C) 0.641； (D) 0.359； (E) 0.590