87. Which of the following species requires the highest energy to remove an electron from its valence shell?
(A) Na⁺
(B) F ⁻
(C) K
(D) Cl⁻
(E) Mg²⁺

83. Identify the missing particle in the following equation:(A) (B) (C) (D)(E) None of the above.

84. How many valence electrons are there in an atom with the electron configuration [noble gas]ns 2 (n – 1)d 10 np 3 ? (A) 2 (B) 3 (C) 5 (D) 10 (E) 15

85. For the process CHCl3(s) → CHCl3(l) , ΔH° = 9.19 kJ/mol and the melting point of chloroform is –64 °C. Calculate ΔS° ? (A) 43.9 J/mol/K (B) 53.9 J/mol/K (C) 26.3 J/mol/K (D) 75.2 J/mol/K (E) None of the above.

86. Atomic orbitals developed using quantum mechanics ________. (A) describe regions of space in which one is most likely to find an electron (B) describe exact paths for electron motion (C) give a description of the atomic structure which is essentially the same as the Bohr model (D) allow scientists to calculate an exact volume for the hydrogen atom (E) are in conflict with the Heisenberg Uncertainty Principle

88. A reaction was found to be zero order in X. Increasing the concentration of X by a factor of 5 will cause the reaction rate to ________. (A) remain constant (B) increase by a factor of 25 (C) increase by a factor of 5 (D) increase by a factor of 10 (E) decrease by a factor of the cube root of 5

89. Which of the following is not a factor determining the energy of activation according to the Arrhenius equation? (ABCDE皆送分)(A) temperature (B) frequency of collision of reacting molecules (C) fraction of collisions with effective orientations (D) frequency factor (E) None of the above.

90. A student needs a solution buffered at pH 4.30 ([H+ ] = 5.0×10−5 M). This student can choose from the following weak acids and their salts to prepare the buffer. Which system will own the best buffering capacity? (A) Benzoic acid (Ka = 6.4 × 10-5 ) (B) Chloroacetic acid (Ka = 1.35 × 10-3 ) (C) Propanoic acid (Ka = 1.3 × 10-5 ) (D) Hypochlorous acid (Ka = 3.5 × 10-8 )

1. The government officials are accused of being involved in ______ practices (A) mundane (B) venal (C) luminous (D) copious

2. Losing your job is just one of the_______ of life. (A) vicissitudes (B) analogous (C) affectation (D) temperance

3. Aspirin and acetaminophen are the oral _____ of first choice in the treatment of mild to moderate pain caused by cancer. (A) analgesics (B) precipitate (C) qualification (D) platitude