20. The point group of H₂O₂ is_______  .
(A) C₂
(B) C_2v
(C) C₃
(D) C_3v
(E) none of the above

16. The coordination geometry of Cr(NO)4 is_____  . (A) tetrahedral (B)trigonal pyramidal (C) see-saw (D) square planar (E) none of tiie above

17. What type of hi^h energy bonds are found in ATP and ADP? (A) ca^oxylic anhydride (B) phosphodiester (C) thioester (D) phosphoanhydride (E) amine

18. Consider the second-order reaction A → products, Mich has a first half-life of 25 s.If the concentration of A after 15.6 s is 0.36 M, determine the initial concentration of A. (A) 0.58 M (B)026M (C) 0.53 M (D)0.14M (E)0.16M

19. Which of the following is the reason for minimum chemical interferences in inductively-coupled plasma? (A) Zeeman efiect correction (B) high ionization efficiency (C) high temperature (D) large number of emission lines (E) none of the above

21. The C–O bond order of CO_ is_______ . (A)1 (B)1.5 (C)2 (D) 2.5 (E) 3

22. The reaction A→B + C is known to be zero order in A with a rate constant of 4.8 x 10-2 mol/L • s at25°C. An experiment was run at 25°C where [A]0 = 4.0 M. What is the concentration of B after 5.0s? (A) 1.7 M (B)4.5 x 10-1 M (C) 3.0 M (D)1.1✖10-1M (E) 2.4 x 10-1 M

23. Which of the following statements is/are true? I. An excited atom can return to its ground state by absorbing electromagnetic radiation. Ⅱ. The ene啊 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) III,v (B)Ⅱ,  III, IV (C) I, Ⅱ, IV (D) I, Ⅱ, III (E)III,IV,V

24. How many electrons can be described by the quantum numbers n = 4, l = 4, ml= 1? (A) 14 (B)6 (C)10 (D)0 (E)2

25. The concentration of OH- ions in a solution is 5.62 mM. Determine the pH of the solution. (A) 11.7 (B)2.2 (C) 14.7 (D) 13.3 (E)5.6

26. In which of the following techniques are we measuring the amount of light absorbed as a function oi wavelength? (A) atomic absorption spectroscopy (B) X-ray difiraction (C) inductively coupled plasma-optical emission spectrometry (lCP-OES) (D) gas chromatography (E) none of the above