6. You analyze for pyridine (K, is approximately 10^-9) by dissolving 0.1000 g of the complex in 100 mL of H₂O and titrating with a 0.01 M HCI solution. Which of the following indicators should be used to detect the endpoint? (Assume that the initial concentration of pyridine is approximately 0.01 M.)
(A) bromophenol blue, pH range of color change = 3.0-4.6
(B) methyl red, pH range of color change = 4.8-6.0
(C) bromothymol blue, pH range of color change = 6.0-7.6
(D) thymol blue, pH range of color change = 8.0-9.6
(E) alizarin yellow, pH range of color change = 10.1-12.0

2. Which one of the following statements about the structure of proteins is incorrect? (A) Disulfide bonds provide strong intrachain interactions. (B) Hydrogen bonding stabilizes the a-helix proteins. (C) Heat can disrupt tertiary structure. (D) Ionized amino acid side chains can form salt bridges within a protein. (E) Nonpolar groups tend to face the outside of a protein in an aqueous solution.

3. Aspirin is formed vi____________ reaction. (A) combustion (B) condensation (C) addition (D) hydrogenation (E) substitution

4. For the process Co(NH3)5CI2+ + CI-→ Co(NH3)4Cl2+ + NH3, what would be the ratio of cis to trans isomers in the product? (A) 1:1 (B) 1:2 (C) 1:4 (D) 4:1 (E) 2:1

5. Which has the greater number of unpaired electrons?I. square planar Ni(CN)42-II. tetrahedral FeCl4- (A) I (B) II (C) Neither I nor II has any unpaired electrons. (D) Both I and II have the same (nonzero) number of unpaired electrons. (E) More information is needed.

7. The deciding factor that makes HF a weak acid is that (A) F2 has a small bond energy. (B) HF has a large bond energy. (C) F- has the largest ionization energy of all the halide ions. (D) the enthalpy of hydration of F- is negative. (E) the entropy for hydration of F- is a large negative value.

8. Which of the following oxides is amphoteric? (A) BeO (B) MgO(C) CaO(D) SrO (E) BaO

9. At 760 K, acetaldehyde decomposes to carbon monoxide and methane:CH3CHO→CH4 + COA plot of In [CH3CHO] versus time is linear. After 530 s, [CH3CHO] decreases to one half of its initial value of 0.10 M.What is the rate law for the reaction? (A)(B)(C)(D) (E)

10. Consider the reaction3A+B+C→D+Ewhere the rate law is defined as   An experiment is carried out where [B]0 = [C]0 = 1.00 M and [A]0 = 2.72 x 10-4 M. What is the half-life for this experiment? (A) 8.19 x 10-7s (B) 1.36 x 10-5s (C) 4.17 x 10-3s (D) 2.21 x 101s (E) 1.66 x 102s

11. 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 only (B) II only (C) III (D) I and Il (E) II and III

12. Which of the following statements is(are) true?I. An excited atom can return to its ground state by absorbing electromagnetic radiation. Ⅱ.energy of an atom is increased when electromagnetic radiation is emi 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