27. Which of the following electron configurations is incorrect?
(A)S^2– : 1s²2s²2p⁶3s²3p⁶
(B) Na⁺:1s² 2s ² 2p⁶
(C) Ga: 1s² 2s² 2p⁶3s²3p⁶4s²3d¹⁰
(D)V:1s²2s²2p⁶3s²3p⁶4s²3d³
(E)I: 1s²2s²2p⁶3s²3p⁶4s² 3d¹⁰4p⁶5s²4d¹⁰5p⁵

23. What is the product called after glycine and alanine undergo condensation reactions? (A) ester (B) dipeptide (C) DNA (D) polysaccharides (E) None of the above.

24. Which compound does not possess a sp2 hybridized orbital? (A) 2-butanone (B) aspirin (C) acetic anhydride (D) 2-propanol (E) aniline

25. Consider the following orderings. Which of these gives a correct trend in ionization energy?I Be ＜ Mg ＜ Ca ＜ SrII Cl ＜ Si ＜ P ＜ AlIII F ＜ Cl ＜ Br ＜ IIV Na+ ＜ Mg2+ ＜ Al3+ ＜ Si4+ (A) I (B) II (C) III (D) IV (E) None of the above.

26. What is the correct order of the following bonds in terms of increasing polarity? (A) N-Cl, P-Cl, As-Cl (B) P-Cl, N-Cl, As-Cl (C) As-Cl, N-Cl, P-Cl (D) P-Cl, As-Cl, N-Cl (E) As-Cl, P-Cl, N-Cl

28. How many moles of Ca(NO3)2 must be added to 0.5 L of a 0.4 M KF solution to begin precipitation of CaF2? For CaF2, Ksp = 4.0 ✖ 10–11.(A) 2.0 ✖ 10–12(B) 1.0 ✖ 10–10 (C) 2.0 ✖10–10(D)1.0 ✖ 10–9(E) 5.0 ✖10–9

29. For the reaction below, Which of the following statements is true? (A) This reaction is endothermic.(B) △G for this reaction has to be negative at all temperatures. (C) Kp is smaller than 1.00 when△G for the reaction is negative. (D) ΔS° for this reaction is negative. (E) All of the above statements are true.

30. Which of the following species needs resonance to adequately describe its structure? (A) H2O(B) CO3 2– (C) NH3 (D) HCN (E) NH4 +

31. An object of mass m is sliding with speed v at some instant across a level tabletop, with which its coefficient of kinetic friction is µ. It then moves through a distance d and comes to rest. Which of the following equations for the speed v is reasonable? (Gravitational acceleration is g) (A) (2μgd) 1/2 (B) (mgd) 1/2 (C) (2μmgd) 1/2 (D) (2μgd) -1/2 (E) (2μd) 1/2

32. A force acting on an object moving along the x axis is given by Fx = (14x − 3x2 ) N, where x is in m. How much work is done by this force as the object moves from x = −1 m to x = +2 m? (A) +12 J (B) +28 J (C) +40 J (D) +42 J (E) −28 J

33. The block shown in the figure is released from rest when the spring is stretched a distance d. If k = 75 N/m, m = 0.5 kg, d =10 cm, and the coefficient of kinetic friction between the block and the horizontal surface is equal to 0.25, what is the speed of the block when it first passes through the position for which the spring is unstretched. (Gravitational acceleration g = 10 m/s2 )(A) 0.53 m/s (B) 0.92 m/s (C) 1.00 m/s (D) 1.22 m/s (E) 1.44 m/s k