25. Consider the following orderings. Which of these gives a correct trend in ionization energy?

I Be ＜ Mg ＜ Ca ＜ Sr

II Cl ＜ Si ＜ P ＜ Al

III F ＜ Cl ＜ Br ＜ I

IV Na⁺ ＜ Mg²⁺ ＜ Al³⁺ ＜ Si⁴⁺
(A) I
(B) II
(C) III
(D) IV
(E) None of the above.

21. How to make a p-type semiconductor? (A) Dope host atoms (Si) with atoms having fewer valence electrons than the host, such as B. (B) Dope host atoms (As) with atoms having fewer valence electrons than the host, such as Se. (C) Dope host atoms (Si) with atoms having more valence electrons than the host, such as As. (D) Dope host atoms (As) with atoms having more valence electrons than the host, such as Ge. (E) None of the above.

22. Based on reaction shown as below, the two complexes can be classified into which type of isomerism? (A) stereoisomerism (B) optical isomerism (C) geometric isomerism (D) ionization isomerism (E) linkage isomerism

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

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

27. Which of the following electron configurations is incorrect? (A)S2– : 1s22s22p63s23p6(B) Na+:1s2 2s 2 2p6(C) Ga: 1s2 2s2 2p63s23p64s23d10(D)V:1s22s22p63s23p64s23d3(E)I: 1s22s22p63s23p64s2 3d104p65s24d105p5

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