47. An atom becomes an ion by:
(A) gaining or losing protons
(B) gaining or losing electrons
(C) gaining or losing neutrons
(D) gaining or losing mass
(E) gaining or losing isotope

43. How many mL of 15 M HNO3 are needed to make 500 mL of a 2 M solution? (A) 0.015 (B) 0.03 (C) 33.3 (D) 66.7 (E) 15

44. Which of the following is NOT a property of alcohols compared to alkenes? (A) exhibit hydrogen bonding (B) higher solubility in water (C) can be oxidized to form aldehydes or ketones (D) undergo dehydration in acid (E) undergo addition reaction with bromine

45. Which of the following process is used by nuclear power plant? (A) Fission (B) Fusion (C) Gamma emission (D) Isotope dilution (E) Radiation

46. What is the complementary sequence (3' → 5') to the DNA segment CAT ? (A) ATG (B) TAA (C) AGG (D) CAT (E) GTA

48. In order for the electron to return to the ground state, what must happen? (A) energy is absorbed (B) energy is released (C) no energy change (D) electron is lost (E) electron is gained

49. Which bond is the least polar? (Electronegativities: H = 2.2; N = 3.0; O = 3.5; P = 2.1; S = 2. 5) (A) N-H (B) P-H (C) O-H (D) S-H (E) P-S

50. For a double displacement reaction demonstration in class, a solution of potassium iodide and a solution of lead (II) nitrate were combined. A precipitate was formed as a product. What color was the precipitate? (A) white (B) green (C) yellow (D) black (E) red

51. Which one is WRONG for the safety in the laboratory? (A) Wear eye protection at all times. (B) In the event of contact with acids, immediately flood the affected area with copious quantities of water. (C) Never work alone in the laboratory. (D) Never use your mouth to provide suction. (E) It is legal to flush solutions containing heavy metal ions or organic liquids down the drain.

52. Which working electrode is used for pH measurement? (A) Ag/AgCl electrode (B) Calomel electrode (C) Hg electrode (D) Glass electrode (E) Pt electrode

53. Salt A and salt B were dissolved separately in 100 mL beakers of water. The water temperatures were measured and recorded as shown in the table below: Salt A: initial water temp. 25.1°C final water temp. 30.2°C Salt B: initial water temp. 25.1°C final water temp. 20.0°C Which statement is a CORRECT interpretation of these data? (A) The dissolving of only salt A was endothermic. (B) The dissolving of only salt B was exothermic. (C) The dissolving of both salt A and salt B was endothermic. (D) The dissolving of salt A was exothermic and the dissolving of salt B was endothermic. (E) The dissolving of both salt A and salt B was endothermic.