Part II. Multiple choice, continued (3 points each). Name:__________________ Please circle your answer. There is only one correct answer to each question. 43. The F-N-F bond angle in the NF3 molecule is slightly less than ___________. A) 90˚ B) 109.5 ˚ C) 120˚ D) 180˚ 44. The angles between sp2 orbitals are _____________. A) 90˚ B) 109.5˚ C) 120˚ D) 180˚ 45. The blending of one s atomic orbital and two p atomic orbitals produces __________. A) three sp hybrid orbitals B) three sp2 hybrid orbitals C) three sp3 hybrid orbitals D) two sp3 hybrid orbitals 46. The π bond in ethylene, CH2CH2, results from the overlap of ___________. A) sp3 hybrid orbitals B) s atomic orbitals C) sp2 hybrid orbitals D) p atomic orbitals 47. The amount of gas that occupies 60.82 L at 31˚ C and 367 mm Hg is _________ mol. A) 1.18 B) 0.850 C) 894 D) 11.6 48. The specific heat of lead is 0.13 J/g-K. How much heat (in J) is required to raise the temperature of 15 g of lead from 22 ˚C to 37 ˚C? A) 7.8 B) 1.9 C) 19 D) 29 49. Which one of the following is a weak acid? A) HNO3 B) HI C) HF D) HClO4 50. Which combination will produce a precipitate? A) NH4OH (aq) and HCl (aq) B) AgNO3 (aq) and Ca(C2H3O2)2 (aq) C) NaCl(aq) and HC2H3O2 (aq) D) NaOH (aq) and Fe(NO3)2 (aq) 51. The density of chlorine (Cl2) gas at 25 ˚C and 450 torr is _______ g/L. A) 20 B) 4.9 C) 1.7 D) 0.86

What is the F-N-F bond angle in the NF3 molecule?

Slightly less than 109.5˚

What is the angle between sp2 orbitals?

120˚

What is produced by the blending of one s atomic orbital and two p atomic orbitals?

Three sp2 hybrid orbitals

What orbital overlap creates the π bond in ethylene, CH2CH2?

The overlap of p atomic orbitals.

How many moles of gas occupy 60.82 L at 31˚ C and 367 mm Hg?

1.18 mol

How much heat is required to raise the temperature of 15 g of lead from 22 ˚C to 37 ˚C?

29 J

Which of the following is a weak acid? A) HNO3 B) HI C) HF D) HClO4

C) HF

Which combination will produce a precipitate? A) NH4OH and HCl B) AgNO3 and Ca(C2H3O2)2 C) NaCl and HC2H3O2 D) NaOH and Fe(NO3)2

D) NaOH and Fe(NO3)2

What is the density of chlorine (Cl2) gas at 25 ˚C and 450 torr?

1.7 g/L