101年 - 101 台灣聯合大學系統_學士班轉學生考試試題_A6：普通化學#139446

1. An element's most stable ion forms an ionic compound with chlorine having the formula \( \text{XCl}_2 \). If the mass number of the ion is 40 and it has 18 electrons, what is the element and how many neutrons does it have? (A)Ar, 22 neutrons (B)Ar, 24 neutrons (C)S, 24 neutrons (D)Ca, 20 neutrons (E)K, 19 neutrons

2. A material is made from Al, Ga, and As. The mole fractions of these elements are 0.25, 0.26, and 0.49, respectively. This material would be (A)a metallic conductor because Al is present. (B)an insulator. (C)a \( p \)-type semiconductor. (D)an \( n \)-type semiconductor. (E)superconductor.

3. How many protons, neutrons, and electrons does the atom \( ^{33}\text{S} \) have? (A)16 protons, 16 neutrons, 33 electrons (B)17 protons, 17 neutrons, 16 electrons (C)16 protons, 16 neutrons, 16 electrons (D)17 protons, 16 neutrons, 17 electrons (E)16 protons, 17 neutrons, 16 electrons

4. A certain substance, X, has a triple-point temperature of \( 20^\circ\text{C} \) at a pressure of 2.0 atm. Which one of the following statements cannot possibly be true? (A)X can exist as a liquid above \( 20^\circ\text{C} \). (B)X can exist as a solid above \( 20^\circ\text{C} \). (C)Liquid X can exist as a stable phase at \( 25^\circ\text{C} \), 1 atm. (D)Both liquid and solid X have the same vapor pressure at \( 20^\circ\text{C} \). (E)All of these statements could be true.

5. Iron is biologically important in the transport of oxygen by red blood cells from the lungs to the various organs of the body. In the blood of an adult human, there are approximately \( 2.60 \times 10^{13} \) red blood cells with a total of 2.90 g of iron. On the average, how many iron atoms are present in each red blood cell? (molar mass for Fe = 55.85 g) (A)\( 8.33 \times 10^{-10} \) (B)\( 1.20 \times 10^9 \) (C)\( 3.12 \times 10^{22} \) (D)\( 2.60 \times 10^{13} \) (E)\( 5.19 \times 10^{-2} \)

6. A liquid-liquid solution is called an ideal solution if

I. it obeys \( PV = nRT \).

II. it obeys Raoult's law.

III. solute-solute, solvent-solvent, and solute-solvent interactions are very similar.

IV. solute-solute, solvent-solvent, and solute-solvent interactions are quite different. (A)I, II, III (B)I, II, IV (C)II, III (D)II, IV (E)I, II

7. To calculate the concentration in molarity of a salt solution, you need to know (A)the mass of the salt added to the solution and the volume of water added to the solution. (B)the mass of the salt added to the solution and the total volume of the solution. (C)the mass of the salt added, the molar mass of the salt, and the total volume of the solution. (D)the molar mass of the salt and the total volume of the solution. (E)the mass of the salt added, the molar mass of the salt, the volume of water added, and the total volume of the solution.

8. Which pair of ions would not be expected to form a precipitate when dilute solutions of each are mixed? (A)\( \text{Cu}^{2+}, \text{S}^{2-} \) (B)\( \text{Ag}^+, \text{Cl}^- \) (C)\( \text{Ca}^{2+}, \text{PO}_4^{3-} \) (D)\( \text{Mn}^{2+}, \text{OH}^- \) (E)\( \text{Mg}^{2+}, \text{SO}_4^{2-} \)

9. The molar mass of a solid as determined by freezing-point depression is 10% higher than the true molar mass. Which of the following experimental errors could not account for this discrepancy? (A)Not all the solid was dissolved. (B)More than the recorded amount of solvent was pipetted into the solution. (C)The solid dissociated slightly into two particles when it dissolved. (D)Some solid was left on the weighing paper. (E)Before the solution was prepared, the container was rinsed with solvent and not dried.

10. The mass of 1.12 L of gas Y is found to be 6.23 g. The density of gas Y is (A)10.6 g/L. (B)5.56 g/L. (C)15.6 g/L. (D)0.200 g/L. (E)0.180 g/L.

11. The molar mass of gas Y is (A)56.0 g/mol. (B)89.0 g/mol. (C)125 g/mol. (D)140. g/mol. (E)157 g/mol.

12. Under which of the following conditions does a gas behave most ideally? (A)STP (B)\( P = 1.0 \text{ atm}, T = 100.0^\circ\text{C} \) (C)\( P = 0.50 \text{ atm}, T = 100.0^\circ\text{C} \) (D)\( P = 0.50 \text{ atm}, T = 0.0^\circ\text{C} \) (E)\( P = 2.0 \text{ atm}, T = -100.0^\circ\text{C} \)

13. Which of the following statements concerning equilibrium is not true? (A)A system that is disturbed from an equilibrium condition responds in such a way as to restore equilibrium. (B)Equilibrium in molecular systems is dynamic, with two opposing processes balancing one another. (C)The value of the equilibrium constant for a given reaction mixture is the same regardless of the direction from which equilibrium is attained. (D)A system moves spontaneously toward a state of equilibrium. (E)The equilibrium constant is independent of temperature.

14. For the reaction \( 2\text{H}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{H}_2\text{O}(g) \), what is the relationship between \( K \) and \( K_p \) at temperature \( T \)? (A)\( K = K_p \) (B)\( K = K_p(RT)^2 \) (C)\( K_p = K(RT)^2 \) (D)\( K = K_p(RT) \) (E)\( K_p = K(RT) \)

15. For a particular system at a particular temperature, there are ________ equilibrium constant(s) and ________ equilibrium position(s). (A)an infinite number of, one (B)one, an infinite number of (C)one, one (D)an infinite number of, an infinite number of (E)none of these

16. Which of the following statements about the equilibrium is false? (A)If the system is heated, the right side is favored. (B)This is a heterogeneous equilibrium. (C)If the pressure on the system is increased by changing the volume, the left side is favored. (D)Adding more \( \text{H}_2(g) \) increases the equilibrium constant. (E)Removing HI as it forms forces the equilibrium to the right.

17. Which of the following species is not amphoteric? (A)\( \text{HSO}_4^- \) (B)\( \text{H}_2\text{PO}_4^- \) (C)\( \text{HPO}_4^{2-} \) (D)\( \text{H}_2\text{O} \) (E)\( \text{HS}^- \)

18. The following acids are listed in order of decreasing acid strength in water.

 \( \text{HI} > \text{HNO}_2 > \text{CH}_3\text{COOH} > \text{HClO} > \text{HCN} \)

According to Brønsted-Lowry theory, which of the following ions is the weakest base? (A)\( \text{I}^- \) (B)\( \text{NO}_2^- \) (C)\( \text{CH}_3\text{COO}^- \) (D)\( \text{ClO}^- \) (E)\( \text{CN}^- \)

19. In deciding which of two acids is the stronger, one must know (A)the concentration of each acid solution only. (B)the pH of each acid solution only. (C)the equilibrium constant of each acid only. (D)all of these. (E)both the concentration and the equilibrium constant of each acid.

20. Which of the following indicates the most acidic solution? (A)\( [\text{OH}^-] = 0.5 \text{ M} \) (B)\( [\text{H}^+] = 0.3 \text{ M} \) (C)\( p\text{OH} = 5.9 \) (D)\( p\text{H} = 1.2 \) (E)\( [\text{H}^+] = 1.0 \times 10^{-4} \text{ M} \)

21. You are given a solution of the weak base Novocain, Nvc. Its pH is 11.00. You add to the solution a small amount of a salt containing the conjugate acid of Novocain, \( \text{NvcH}^+ \). Which statement is true? (A)The pH and the pOH both increase. (B)The pH and the pOH both decrease. (C)The pH and the pOH remain unchanged. (D)The pH increases and pOH decreases. (E)The pH decreases and the pOH increases.

22. Consider a solution of 2.0 \( M \) HCN and 1.0 \( M \) NaCN (\( K_a \) for HCN = \( 6.2 \times 10^{-10} \)). Which of the following statements is true? (A)The solution is not a buffer because [HCN] is not equal to [\( \text{CN}^- \)]. (B)The pH will be below 7.00 because the concentration of the acid is greater than that of the base. (C)\( [\text{OH}^-] > [\text{H}^+] \) (D)The buffer will be more resistant to pH changes from addition of strong acid than to pH changes from addition of strong base. (E)The pH will be equal to 7.00.

23. Suppose you add 45 J of heat to a system, let it do 10 J of expansion work, and then return the system to its initial state by cooling and compression. Which statement is true for this process? (A)\( \Delta H < \Delta E \) (B)The work done in compressing the system must exactly equal the work done by the system in the expansion step. (C)\( \Delta H = 70 \text{ J} \) (D)The change in the internal energy for this process is zero. (E)\( \Delta H = 35 \text{ J} \)

24. \( \text{C}_2\text{H}_5\text{OH}(l) + 3\text{O}_2(g) \rightarrow 2\text{CO}_2(g) + 3\text{H}_2\text{O}(l), \quad \Delta H = -1.37 \times 10^3 \text{ kJ} \) For the combustion of ethyl alcohol as described in the above equation, which of the following statements is(are) true?

I. The reaction is exothermic.

II. The enthalpy change would be different if gaseous water were produced. 

III. The reaction is not an oxidation-reduction one.

 IV. The products of the reaction occupy a larger volume than the reactants. (A)I, II (B)I, II, III (C)I, III, IV (D)III, IV (E)I only

25. Which statement is true of a process in which 1 mol of a gas is expanded from state A to state B? (A)When the gas expands from state A to state B, the surroundings are doing work on the system. (B)The amount of work done in the process must be the same, regardless of the path. (C)It is not possible to have more than one path for a change of state. (D)The final volume of the gas will depend on the path taken. (E)The amount of heat released in the process will depend on the path taken.

26. Calculate the difference in \( \Delta E \) between the first sample and the second sample. (A)0 (B)1.00 L\(\cdot\)atm (C)2.00 L\(\cdot\)atm (D)3.00 L\(\cdot\)atm (E)4.50 L\(\cdot\)atm

27. Calculate the difference in \( q \) between the first sample and the second sample. (A)-2.00 L\(\cdot\)atm (B)-1.00 L\(\cdot\)atm (C)1.00 L\(\cdot\)atm (D)2.00 L\(\cdot\)atm (E)0.00 L\(\cdot\)atm

28. When a student performs an endothermic reaction in a calorimeter, how (if any) does the calculated value of \( \Delta H \) differ from the actual value if the heat exchanged with the calorimeter is not taken into account? (A)\( \Delta H_{\text{calc}} \) is more negative because the calorimeter always absorbs heat from the reaction. (B)\( \Delta H_{\text{calc}} \) is less negative because the calorimeter absorbs heat from the reaction. (C)\( \Delta H_{\text{calc}} \) is more positive because the reaction absorbs heat from the calorimeter. (D)\( \Delta H_{\text{calc}} \) is less positive because the reaction absorbs heat from the calorimeter. (E)\( \Delta H_{\text{calc}} \) equals the actual value because the calorimeter does not absorb heat.

29. A mixture of hydrogen and chlorine remains unreacted until it is exposed to ultraviolet light from a burning magnesium strip. Then the following reaction occurs very rapidly.

\( \text{H}_2(g) + \text{Cl}_2(g) \rightarrow 2\text{HCl}(g) \quad \Delta G = -45.54 \text{ kJ}, \Delta H = -44.12 \text{ kJ}, \Delta S = -4.76 \text{ kJ} \),

Select the statement below that best explains this behavior. (A)The reactants are thermodynamically more stable than the products. (B)The reaction has a small equilibrium constant. (C)The ultraviolet light raises the temperature of the system and makes the reaction more favorable. (D)The negative value for \( \Delta S \) slows down the reaction. (E)The reaction is spontaneous, but the reactants are kinetically stable.

30. Which of the following result(s) in an increase in the entropy of the system?

I. (See diagram.) II. \( \text{Br}_2(g) \rightarrow \text{Br}_2(l) \) III. \( \text{NaBr}(s) \rightarrow \text{Na}^+(aq) + \text{Br}^-(aq) \) IV. \( \text{O}_2(298\text{ K}) \rightarrow \text{O}_2(373\text{ K}) \) V. \( \text{NH}_3(1\text{ atm}, 298\text{ K}) \rightarrow \text{NH}_3(3\text{ atm}, 298\text{ K}) \) (A)I (B)II, V (C)I, III, IV (D)I, II, III, IV (E)I, II, III, V

31. One mole of an ideal gas at \( 25^\circ\text{C} \) is expanded isothermally from 5.0 L to 10.0 L under such conditions that no work is produced in the surroundings. Which statement is correct? (A)\( \Delta S_{\text{gas}} = 0 \) (B)\( \Delta S_{\text{gas}} = R\ln 2/298 \) (C)\( \Delta S_{\text{univ}} = 0 \) (D)\( \Delta S_{\text{surr}} = 0 \) (E)\( \Delta S_{\text{gas}} = \Delta S_{\text{surr}} \)

32. For which process is \( \Delta S \) negative? (A)evaporation of 1 mol of \( \text{CCl}_4(l) \) (B)mixing 5 mL of ethanol with 25 mL of water (C)compressing 1 mol of Ne at constant temperature from 1.5 atm to 0.5 atm (D)raising the temperature of 100 g of Cu from 275 K to 295 K (E)grinding a large crystal of KCl to powder

33. When a stable diatomic molecule spontaneously forms from its atoms, what are the signs of \( \Delta H^\circ \), \( \Delta S^\circ \), and \( \Delta G^\circ \), respectively? (A)+ + + (B)+ - - (C)- + + (D)- - + (E)- - -

34. For the reaction \( \text{A} + \text{B} \rightarrow \text{C} + \text{D} \), \( \Delta H^\circ = +40 \text{ kJ} \) and \( \Delta S^\circ = +50 \text{ J/K} \). Therefore, the reaction under standard conditions is (A)spontaneous at temperatures less than 10 K. (B)spontaneous at temperatures greater than 800 K. (C)spontaneous only at temperatures between 10 K and 800 K. (D)spontaneous at all temperatures. (E)nonspontaneous at all temperatures.

35. A strip of copper is placed in a 1 \( M \) solution of copper nitrate, and a strip of silver is placed in a 1 \( M \) solution of silver nitrate. The two metal strips are connected to a voltmeter by wires, and a salt bridge connects the solutions. The following standard reduction potentials apply:

\( \text{Ag}^+(aq) + \text{e}^- \rightarrow \text{Ag}(s) \quad E^\circ = +0.80 \text{ V} \)

 \( \text{Cu}^{2+}(aq) + 2\text{e}^- \rightarrow \text{Cu}(s) \quad E^\circ = +0.34 \text{ V} \)

When the voltmeter is removed and the two electrodes are connected by a wire, which of the following does not take place? (A)Electrons flow in the external circuit from the copper electrode to the silver electrode. (B)The silver electrode increases in mass as the cell operates. (C)There is a net general movement of silver ions through the salt bridge to the copper half-cell. (D)Negative ions pass through the salt bridge from the silver half-cell to the copper half-cell. (E)Some positive copper ions pass through the salt bridge from the copper half-cell to the silver half-cell.

36. What is \( E^\circ \) for this cell? (A)1.82 (B)0.36 V (C)4.75 V (D)1.79 V (E)4.40 V

37. Which of the following statements about this cell is false? (A)This is a galvanic cell. (B)Electrons flow from the Pt electrode to the Cr electrode. (C)Reduction occurs at the Pt electrode. (D)The cell is not at standard conditions. (E)To complete the circuit, cations migrate into the left half-cell and anions migrate into the right half-cell from the salt bridge.

38. For a reaction in a voltaic cell, both \( \Delta H^\circ \) and \( \Delta S^\circ \) are positive. Which of the following statements is true? (A)\( E^\circ_{\text{cell}} \) will increase with an increase in temperature. (B)\( E^\circ_{\text{cell}} \) will decrease with an increase in temperature. (C)\( E^\circ_{\text{cell}} \) will not change when the temperature increases. (D)\( \Delta G^\circ > 0 \) for all temperatures. (E)None of the above statements is true.

39. 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

40. Which of the following is a reasonable criticism of the Bohr model of the atom? (A)It makes no attempt to explain why the negative electron does not eventually fall into the positive nucleus. (B)It does not adequately predict the line spectrum of hydrogen. (C)It does not adequately predict the ionization energy of the valence electron(s) for elements other than hydrogen. (D)It does not adequately predict the ionization energy of the first-energy-level electrons for elements other than hydrogen. (E)It shows the electrons to exist outside of the nucleus.

41. An electron in a 10.0-nm one-dimensional box is excited from the ground state into a higher energy state by absorbing a photon with wavelength \( 1.374 \times 10^{-5} \text{ m} \). Determine the final energy level for this transition. (A)\( n = 2 \) (B)\( n = 3 \) (C)\( n = 4 \) (D)\( n = 5 \) (E)\( n = 6 \)

42. For an electron in a one-dimensional box, what is the minimum energy to excite the electron from the ground state? (A)\( \frac{h^2}{8mL^2} \) (B)\( \frac{2h^2}{8mL^2} \) (C)\( \frac{3h^2}{8mL^2} \) (D)\( \frac{4h^2}{8mL^2} \) (E)\( \frac{5h^2}{8mL^2} \)

43. Which of the following statements is false? (A)An orbital can accommodate at most two electrons. (B)The electron density at a point is proportional to \( \psi^2 \) at that point. (C)The spin quantum number of an electron must be either +1/2 or -1/2. (D)A 2p orbital is more penetrating than a 2s; that is, it has a higher electron density near the nucleus and inside the charge cloud of a 1s orbital. (E)In the usual order of filling, the 6s orbital is filled before the 4f orbital.

44. For which of the following elements does the electron configuration for the lowest energy state show a partially filled d orbital? (A)V (B)K (C)Cu (D)Ga (E)Ar

45. Which of the following bonds would be the most polar without being considered ionic? (A)Mg-O (B)C-O (C)O-O (D)Si-O (E)N-O

46. Which of the following ionic compounds has the largest lattice energy; that is, which has the lattice energy most favorable to a stable lattice? (A)CsI (B)LiI (C)LiF (D)CsF (E)MgO

47. Order the following from shortest to longest bond:

\( \text{C}_2, \text{B}_2, \text{H}_2, \text{N}_2 \) (A)\( \text{H}_2, \text{N}_2, \text{C}_2, \text{B}_2 \) (B)\( \text{N}_2, \text{C}_2, \text{B}_2, \text{H}_2 \) (C)\( \text{C}_2, \text{N}_2, \text{H}_2, \text{B}_2 \) (D)\( \text{C}_2, \text{B}_2, \text{H}_2, \text{N}_2 \) (E)\( \text{H}_2, \text{B}_2, \text{C}_2, \text{N}_2 \)

48. For how many of the following does the bond order decrease if you add one electron to the neutral molecule?

\( \text{B}_2, \text{Si}_2, \text{P}_2, \text{F}_2 \) (A)0 (B)1 (C)2 (D)3 (E)4

49. Which of the following electron distributions among the molecular orbitals best describes the NO molecule?

(A)I (B)II (C)III (D)IV (E)V

50. Which one of the following statements about solid Cu (face-centered cubic unit cell) is incorrect? (A)It will conduct electricity. (B)There are two atoms per unit cell. (C)The number of atoms surrounding each Cu atom is 12. (D)The solid has a cubic closest-packed structure. (E)The length of a face diagonal is four times the Cu radius.