84. Five molecules are shown as below. Which one has the highest ionic strength?
(A) B(OH)₃
(B) HNO₃
(C) Na₂HPO₄
(D) CaCO₃
(E) BaSO₄

80. Which of the following statements about “The Bohr Model” and “Particle in a Box” is TRUE? (A) For an electron trapped in a one-dimensional box, as the length of the box increases, the spacing between energy levels will increase. (B) The total probability of finding a particle in a one-dimensional box (length is L) in energy level n = 4 between x = L/4 and x = L/2 is 50%. (C) If the wavelength of light necessary to promote an electron from the ground state to the first excited state is λ in a one-dimensional box, then the wavelength of light necessary to promote an electron from the first excited state to the third excited state will be 3λ. (D) A function of the type A cos(Lx) can be an appropriate solution for the particle in a onedimensional box. (E) Assume that a hydrogen atom’s electron has been excited to the n = 5 level. When this excited atom loses energy, 10 different wavelengths of light can be emitted.

81. Which of the following statements concerning a face-centered cubic unit cell and the corresponding lattice, made up of identical atoms, is incorrect? (A) The coordination number of the atoms in the lattice is 8. (B) The packing in this lattice is more efficient than for a body-centered cubic system. (C) If the atoms have radius r, then the length of the cube edge is (D) There are four atoms per unit cell in this type of packing. (E) The packing efficiency in this lattice and hexagonal close packing are the same.

82. Which of the followings will give a solution with a pH ＞ 7, but is not an Arrhenius base in the strict sense? (A) CH3NH2 (B) NaOH (C) CO2 (D) Ca(OH)2 (E) CH4

83. Pentane, , boils at 35°C. Which of the followings is true about kinetic energy, Ek, and potential energy, Ep, when liquid pentane at 35°C is compared with pentane vapor at 35°C? (A) Ek(g) ＜ Ek(l)； Ep(g) ≈ Ep(l) (B) Ek(g) ＞ Ek(l)； Ep(g) ≈ Ep(l) (C) Ep(g) ＜ Ep(l)； Ek(g) ≈ Ek(l) (D) Ep(g) ＞ Ep(l)； Ek(g) ≈ Ek(l) (E) Ep(g) ≈ Ep(l)； Ek(g) ≈ Ek(l)

85. Hydroxylamine nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. Determine its empirical formula. (A) HNO (B) H2NO2 (C) (D)(E) H2NO3

86. Given the following two standard reduction potentials,determine for the standard reduction potential of the half-reaction (A) 0.40 V (B) 0.77 V (C) -0.40 V (D) -0.11 V (E) 0.11 V

87. The rate law for a reaction is found to be Rate = k[A]2 [B]. Which of the following mechanisms gives this rate law?(A) I (B) II (C) III (D) I & II (E) II & III

88. When the redox reaction in basic solution: is balanced using the smallest whole-number coefficients, the coefficient of H2O is x and the sum of all coefficients is y. What is the sum of x and y, (x + y)? (A) 9 (B) 10 (C) 11 (D) 12 (E) 13

89. Which of the followings is the best representation of the titration curve which will be obtained in the titration of a weak acid (0.10 mol ) with a strong base of the same concentration? (A) (B) (C) (D) (E)

90. The students used salicylic acid and acetic anhydride to synthesize aspirin in the experiment of “The Preparation of Aspirin”. The chemical reaction is shown as below: Which compound will react with FeCl3 to become a purple complex? (A) Salicylic acid (B) Acetic anhydride (C) Aspirin (D) Acetic acid (E) 18 M sulfuric acid