Exam 3 Chem 1100 Fall 2003 Dr. Byrd

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

1) Atoms of which element, indicated by letter on the periodic table, have the orbital-filling diagram shown below?

A) A

B) B

C) C

D) D

E) None of these are correct.

2) How many valance electrons does a neutral sulfur atom have?

A) 6 B) 4 C) 16 D) 2 E) 8

3) Of the following, which atom has the largest atomic radius?

A) K B) Br C) Cl D) Na E) Ca

4) What is the ground-state electron configuration of tellurium?

A) [Kr]5s²5p⁶5d⁸ B) [Kr]4d¹⁰5s²5p⁴

C) [Kr]5s²5p⁴ D) [Kr]4f¹⁴4d¹⁰5s²5p⁴

5) For a multielectron atom, a 3s orbital lies lower in energy than a 3p orbital because

A) there are more p orbitals than s orbitals in a given shell.

B) other electrons more effectively shield electrons in the 3s orbital from the nucleus.

C) a 3p orbital has more nodal surfaces than a 3s orbital.

D) other electrons more effectively shield electrons in the 3p orbital from the nucleus.

E) none of the above are correct

6) Which two ions have the same electron configuration in the ground state?

A) Rb⁺ and Cs⁺

B) Se²⁺ and I^-

C) Ba²⁺ and I^-

D) Fe²⁺ and Fe³⁺

E) None of the above

7) What is the ground-state electron configuration of the ion Zn²⁺?

A) [Ar]3d¹⁰4s²

B) [Ar]3d¹⁰

C) [Ar]3d¹⁰4s²4p²

D) [Ar]3d⁸4s²

E) None of the above are correct

8) Of the following, which element has the highest first ionization energy?

A) sodium

B) aluminum

C) silicon

D) magnesium

E) potassium

9) Which ionization process requires the most energy?

A) P²⁺(g) Â P³⁺(g) + e^-

B) P(g) Â P⁺(g) + e^-

C) P³⁺(g) Â P⁴⁺(g) + e^-

D) P⁺(g) Â P²⁺(g) + e^-

E) P⁴⁺(g) Â P⁵⁺(g) + e^-

10) Which of the following ionic compounds would be expected to have the highest lattice energy?

A) NaCl

B) NaI

C) NaBr

D) NaF

E) KI

11) What is the ground-state electron configuration of Se^2-?

A) [Ar]3d¹⁰4s²4p⁴

B) [Ar]3d¹⁰4s²4p⁶

C) [Ar]3d¹⁰4s²4p²

D) [Ar]3d¹²4s²4p⁴

E) None of the above

12) Covalent bonding is a

A) gain of electrons.

B) sharing of electrons.

C) transfer of electrons.

D) loss of electrons.

E) None of the above

13) The greater the electronegativity difference between two bonded atoms, the

A) greater the bond order.

B) more unstable the bond.

C) greater the ionic character of the bond.

D) greater the covalent character of the bond.

E) None of the above

14) Which is the most acceptable electron dot structure for N₂H₂?

A)

B)

C)

D)

E) None of the above are acceptable.

15) Assign formal charges to each atom in the resonance form for SOCl₂ given below.

A) -1 for Cl, +4 for S, and -2 for O

B) 0 for Cl, +1 for S, and -1 for O

C) -1 for Cl, -2 for S, and -2 for O

D) 0 for Cl, 0 for S, and 0 for O

E) None of the above are correct

16) What is the molecular geometry of AsCl₃?

A) trigonal planar

B) tetrahedral

C) T-shaped

D) trigonal pyramidal

E) bent

17) Which of the following best describes ICl₂^-1? It has a molecular geometry that is

A) non-linear molecular shape with no lone pairs on the I atom.

B) linear molecular shape with lone pairs on the I atom.

C) non-linear molecular shape with lone pairs on the I atom.

D) linear molecular shape with no lone pairs on the I atom.

E) noe of the above are correct

18) Which of the following would be expected to have sp² hybridization on atom A?

A) I, II, and III

B) II

C) I and III

D) I and IV

E) None have sp² hybridization on atom A

19) Identify the set of hybrid orbitals shown below.

A) sp²

B) sp³

C) sp^3d

D) sp^3d2

E) sp^3d3

20) Which drawing represents a p bonding molecular orbital for a homonuclear diatomic molecule?

A)

B)

C)

D)

21) Which depends only on the initial and final state?

A) q + w B) w C) q - w D) q

22) For a process at constant volume,

A) q = 0, w = 0, and DE = 0.

B) w = 0 and DE = q.

C) w = 0 and DE = DH.

D) w = 0 and DH = q.

23) Calculate the work, w, done on a system when a gas contracts from 35 L to 15 L against a constant external pressure of 1.5 atm. [1 L \'97 atm = 101 J]

A) +3.0 kJ

B) +5.3 kJ

C) -3.0 kJ

D) -5.3 kJ

E) none of the above

24) It takes 11.2 kJ of energy to raise the temperature of 145 g of benzene from 25.0°C to 70.0°C. What is the specific heat of benzene?

A) 1.10 J/(g °C) B) 1.72 J/(g °C)

C) 5.41 J/(g °C) D) 3.48 J/(g °K)

25) Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below. When 0.010 mol of Na is added to 100.00 g of water, the temperature of the resulting solution rises from 25.00°C to 29.30°C. If the specific heat of the solution is 4.18 J/(g °C), calculate DH for the reaction, as written.

Na(s) + H₂O(l) Â NaOH(aq) + 1/2 H₂(g) DH = ?

A) -362 kJ

B) -90. kJ

C) -5.4 kJ

D) -180 kJ

E) none of the above

26) Calculate the lattice energy for NaCl(s) using a Born-Haber cycle and the following information: