102年 - 高雄醫學大學 102 學年度學生轉系考試【普通化學】試題#86817

選擇題 (20)

1. Radioactive elements decay via first-order kinetics. Consider a certain type of nucleus that has a rate constant of 2.6✕10^–2 h^–1. A sample contains 6.5✕10⁸ radioactive nuclides. Calculate the time required for 61% of the nuclides to decompose. (A) 1.9 ✕10¹ h; (B) 1.6✕10¹ h; (C) 0.8✕10¹ h; (D) 3.6✕10¹ h; (E) 2.4✕10¹ h

2. Consider the following four compounds:

Which of these compounds would have the same physical properties (melting point, boiling point, density, and so on)?(A) I and II; (B) I and III; (C) II and III; (D) III and IV; (E) I and IV.

3. Which of the following statement about biomolecules is incorrect? (A) Protein synthesis takes place in the cytoplasm of the cell. (B) Each gene in the DNA molecule codes for a specific protein. (C)Messenger RNA can be found in both the nucleus and the cytoplasm of each cell. (D)When a peptide bond is formed, H2O is produced. (E)All of these statements are true.

4. What is the most abundant (by mass) element found in the human body? (A) carbon; (B) hydrogen; (C) calcium; (D) oxygen; (E) water.

5. Calculate the molality of a solution containing 21.2 g of C₆H₁₂O₆ in 249.6 mL of water (assume the density of water : 1.00 g/mL; density of the solution : 1.05 g/mL;). (A) 0.471 m; (B) 0.435 m; (C) 0.0783 m; (D) 0.00841 m; (E) 0.458 m

6. Consider the molecular-orbital description of the NO– anion. Which of the following statements is false? (A) NO^– is paramagnetic; (B) NO^– is isoelectronic with CO; (C) The bond energy in NO⁺ is greater than the bond energy in NO^–; (D) The bond order in NO^– is 2; (E) All of these statements are false.

7. Which of the following statements about solids is false? (A) The hexagonal closest-packed structure is ABAB.... (B) A body-centered cubic unit cell has four atoms per unit cell. (C) For unit cells having the same edge length, a simple cubic structure would have a smaller density than abody-centered cube. (D) Atoms in a solid consisting of only one element would have six nearest neighbors if the crystal structurewas a simple cubic array. (E) All the statements are correct.

8. What is the rate law for the following reaction, given the data below?
(A) Rate = k[NO]; (B) Rate = k[NO]²; (C) Rate = k[NO]²[H₂]; (D) Rate = k[NO][H₂]; (E) Rate = k[N₂O][H₂O]

9. Consider the following molecules:
I. BF₃ ; II. CHBr₃(C is the central atom.) ; III. Br₂ ; IV. XeCl₂ ; V. CO ; VI. SF₄
Which of these molecules violate the octet rule? (A) I, II, IV; (B) I, III, IV, VI; (C) III, V, VI; (D) I, IV, VI; (E) I, II, IV, VI

10. The wavelength of light associated with the n = 2 to n = 1 electron transition in the hydrogen spectrum is 1.216✕10^–7 m. By what coefficient should this wavelength be multiplied to obtain the wavelength associated with the same electron transition in the Li²⁺ ion? (A) 1/9; (B) 1/7; (C) 1/4; (D) 1/3; (E) 1

11.For a reaction in a voltaic cell, both △H° and △S° are positive. Which of the following statements is true? (A) E°cell will increase with an increase in temperature. (B) E°cell will decrease with an increase in temperature. (C) E°cell will not change when the temperature increases. (D) G° > 0 for all temperatures. (E) None of the above statements is true.

12.When a nonvolatile solute is added to a volatile solvent, the solution vapor pressure a , the boiling point b , the freezing point c , and the osmotic pressure across a semipermeable membrane d . Please select the most appropriate descriptions that fit the blanks alphabetic. (A) decreases, increases, decreases, decreases (B) decreases, increases, decreases, increases (C) increases, increases, decreases, increases (D) decreases, decreases, increases, decreases (E) increases, decreases, increases, decreases

13.On a cold winter day, a steel metal fence post feels colder than a wooden fence post of identical size because: (A) The specific heat capacity of steel is higher than the specific heat capacity of wood. (B) The specific heat capacity of steel is lower than the specific heat capacity of wood. (C) Steel has the ability to resist a temperature change better than wood. (D) The mass of steel is less than wood so it loses heat faster. (E) Two of the above statements are true.

14.Using the following data, calculate the standard heat of formation of the compound ICl in kJ/mol:
(A) –211 kJ/mol; (B) –14.6 kJ/mol; (C) 16.8 kJ/mol; (D) 245 kJ/mol; (E) 439 kJ/mol

15.A student uses 16.60 mL of 0.100 M NaOH to titrate a 0.2000-g sample of an unknown acid. Which of the following acids is the unknown most likely to be? Assume that only the hydrogens bonded to oxygen are titrated by the sodium hydroxide and that, because of experimental error, the student's value may not be identical to the theoretical value. (A) succinic acid, HOOCCH₂CH₂COOH, molar mass 118 (B) benzoic acid, C₆H₅COOH, molar mass 122 (C) phthalic acid, C₆H₄ (COOH)₂, molar mass 166 (D) oxalic acid, HOOCCOOH, molar mass 90 (E) not enough information

16.A 0.050 M aqueous solution of a weak monoprotic acid is 1.2 % ionized at equilibrium at 298 K. Calculate Ka for this acid. (A) 3.4✕10^–2 (B) 6.4 ✕10^–8 (C) 7.3✕10^–33 (D) 29 (E) none of these

17. At a certain temperature, K for the reaction : 2NO₂⇌ N₂O₄ is 7.5 L/mol. If 2.0 mol of NO₂ is placed in a 2.0-liter container and permitted to react at this temperature, calculate the concentration of N₂O₄ at equilibrium. (A) 0.39 mol/L; (B) 0.65 mol/L; (C) 0.82 mol/L; (D) 7.5 mol/L; (E) none of these

18.A sample of nitrogen gas has a volume of 150.0 mL at STP. What volume does the gas occupy if the absolute temperature and pressure are each tripled? (A) 450.0 mL; (B) 50.00 mL; (C) 150.0 mL; (D) 500.0 mL; (E) 67.20 L

19.You dissolve 15.71 g of NH₄NO₃ in 150.0 mL of solution (call this solution A). You take 20.0 mL of solution A and add water until the total volume is 75.0 mL (call this solution B). You take 15.0 mL of solution B and add 25.0 mL of water to it (call this solution C). You mix 10.0 mL of solution B and 10.0 mL of solution C (call this solution D). What is the concentration of ammonium nitrate in solution D? (A) 0.190 M; (B) 0.279 M; (C) 0.131 M; (D) 0.240 M; (E) none of these

20. Which intermolecular force is the strongest? (A) dipole-dipole interactions; (B) London dispersion forces; (C) hydrogen bonding; (D) ionic bonding; (E) polar covalent bonds

申論題 (8)

a. Calculate ∆G^o and K for the cell reaction at 25^oC.

b. Calculate ξcell at 25^oC when [Au³⁺] = 0.050 M and [Tl⁺] = 1.0x10^-3 M

2. The mass percent of carbon in a typical human is 18 %, and the mass percent of ¹⁴C in natural carbon is 1.6✕10^-10 %. Assuming a 200-lb person, how many decay events per second occur in this person due exclusively to β-decay of ¹⁴C (for ¹⁴C, t_1/2 = 5730 years; 1 lb = 0.454 kg)

3. Carbonate buffers are important in regulating the pH of blood at 7.40. If the carbonic acid concentration in a sample of blood is 1.2 mM, determine the bicarbonate ion concentration required to buffered the pH of blood at pH = 7.40.
H₂CO_3(aq)⇌HCO₃^-_(aq) + H⁺_(aq); K_a = 4.3✕10^-7

4. Trans fats are made by treating free-flowing oils with hydrogen, a catalyst, and high heat to change the structure of the oil. Although the hydrogenated oils are much more stable toward spoilage, a serious drawback to this process has been realized that the trans form of the fat poses serious health risks when compared to naturally occurring cis form of the oils. The part of the hydrogenated process that results in the formation of trans fat can be summarized as follows: cis fat_(aq) + H_2(aq)⇌ trans fat_(aq) A typical value of equilibrium constant of this type of reaction is about 5.0. If we start with 0.1 mol/L each of _cis fat and H_2. Calculate the equilibrium concentrations of cis fat and trans fat, respectively.

5. Theophylline is a pharmaceutical drug that is sometimes used to help with lung function. You observe a case where initial laboratory results indicate that the concentration of theophylline in a patient’s body decreased from 0.002 M to 0.001 M in 24 hours. In another 12 hours the drug concentration was found to be 0.0005 M. What is the value of the rate constant for the metabolism of this drug in body?

6. Assuming the MgO unit cell has a face-centered cubic arrangement of the anions with cations in the octahedral holes. (a.) If the density of MgO is 3.58 g/cm³ , estimate the radius of O^2- anions and Mg²⁺ cations (in nanometer). (b.) Calculate the space occupied percentage (%) by ions in a unit cell of MgO (Assuming that cations and anions touch along the edges of the unit cell; anions touch along the diagonals for each face; Mg: 24.31 g/mol)

7. Plot all the possible Lewis structures of XeO₃ and indicate which Lewis structure or structures are most appropriate according to the formal charges.

102年 - 高雄醫學大學 102 學年度學生轉系考試【普通化學】試題#86817

試卷資訊

選擇題 (20)

申論題 (8)