21. _____is the upward force exerted on an object in a gaseous or liquid fluid. The mass measured by an analytical balance in air is _____ its actual mass.
(A) Buoyancy; heavier than
(B) Buoyancy; lighter than
(C) Electromagnetic force; heavier than
(D) Electromagnetic force; lighter than
(E) Tare; equal to

17. Which of the following are state functions? (A) work, heat, enthalpy (B) heat, enthalpy, energy (C) enthalpy, energy (D) work, heat, enthalpy, energy (E) work, heat

18. The mass of a sample of calcium carbonate powder is measured using weight by difference. If a vial containing calcium carbonate powder has an initial mass of 87.36 ± 0.03 g and a final mass of 76.99 ± 0.03 g, what mass of calcium carbonate was taken? (A) 10.37±0.04 g (B) 10.37±0.03 g (C) 10.370±0.042 g (D) 10.370 ± 0.004 g (E) 10.370 ± 0.005 g

19. Which of the following ionic compounds has (in absolute values) the largest lattice energy; that is, which has the lattice energy most favorable to a stable lattice? (A) LiF (B) Lil (C) CsF (D) MgO (E) CsI

20. What is the key step in the Heck reaction? (A) radical generation (B) carbocation formation (C) palladium-catalyzed oxidative addition and reductive elimination (D) nucleophilic substitution (E) decarboxylation

22. How many electrons in an atom can have the quantum numbers n = 4, 1 = 2? (A) 18 (B) 32 (C) 2 (D) 6 (E) 10

23. Which of the following options shows the molecules in the order from most polar to least polar? ("=" indicates that two molecules are similarly polar) (A) CF2Cl2 ＞ CF2H2 ＞ CCl2H2 ＞ CH4 = CCl4 (B) CF2H2 ＞ CCl2H2 ＞ CF2Cl2 ＞ CH4 = CCl4 (C) CH4＞ CF2Cl2 ＞ CF2H2 ＞ CCl4 ＞ CCl2H2 (D) CF2Cl2 ＞ CF2H2 ＞ CCl4 ＞ CCl2H2 ＞ CH4 (E) CH4 ＞ CF2H2 ＞ CF2Cl2 ＞ CCl4 ＞ CCl2H2

24. Lead(II) nitrate reacts with sodium chloride in aqueous solution to form a precipitate. What is the net ionic equation for the precipitation process? (A)(B)(C) (D)(E)

25. Which of the following anions is the strongest base? (A)(B)(C)(D)(E)

26. Polystyrene is an addition polymer of styrene. What would be the effect, if some divinylbenzene were added to styrene and then polymerized? (A) The polymer would be more flexible. Divinylbenzene acts as a plasticizer. (B) The polymer would be less flammable than pure polystyrene. (C) There would be an effect, but it cannot be predicted. (D) There would be no effect on the properties of the polymer. (E) Divinylbenzene would act as a cross-linking agent, making the polymer stronger.

27. Which of the following quantum model is most adequate as an approximation to describe an t-electron moving in ẞ-carotene? (A) a particle in a one-dimensional box (B) harmonic oscillator (C) a freely moving particle (D) rotation in two dimensions (E) a rigid rotor