2 g h 1989 kj o 3 g 15o 2 g h 1423 kj o 2 g 2o g h

2
( g )  H = –198.9 kJ
O
3
( g )  1.5O
2
( g )  H = –142.3 kJ
O
2
( g )  2O( g )  H = 495.0 kJ
A. –551.6 kJ
B. 153.8 kJ
C. 190.9 kJ
D. –304.1 kJ
E. 438.4 kJ
____ 38. Which one of the following sets of quantum numbers is not permitted?? ____ 39. What is the electronic configuration for Cr + ?
4d
3

____ 40. Which of the following species has the smallest radius?
____ 41. Select the element with the highest first ionization energy.
A. Mg
B. Ca
C. Ba
D. Ra
E. K
____ 42. From the data given below, calculate the approximate enthalpy change of reaction for the reaction
below.
CH
4
(g) + 2O
2
(g)  CO
2
(g) + 2H
2
O(g)
bond enthalpy kJ/mol
C–H 414
C–C 347
C=C 611
C–O 351
C=O 803
O–H 463
O=O 498
H–H 436
Form A, Page 13 of 17

____ 43. Which statement best describes the formal charges on the atoms in PO
4
3  ?
____ 44. Construct correct Lewis dot structures for the three molecules below. Determine which
compounds, if any, have an extended octet.
CF
4
SF
4
ClF
3
I II III
____ 45. Using VSEPR Theory, predict the electron-pair geometry, the molecular geometry, and the
smallest approximate F–Cl–F bond angle of ClF
3
.
A. trigonal bipyramidal, T-shaped, 90 
B. tetrahedral, trigonal planar, 109.5 
C. trigonal bipyramidal, trigonal pyramidal, 109.5 
D. trigonal bipyramidal, trigonal planar, 120 
E. trigonal planar, trigonal planar, 120 
Form A, Page 14 of 17

____ 46. Which of the following has a trigonal planar molecular geometry?
I. nitrate ion
II. carbonate ion
III. sulfite ion
IV. selenite ion
____ 47. Which of the following molecules are polar?
I. ICl
4
–
II. NH
4
+
III. IF
5
IV. RnF
2
____ 48. Determine the hybridization around each central atom.
NH
2
 NH
3
CO
3
2–
2
3
d
Form A, Page 15 of 17

____ 49. Which of the following molecules are paramagnetic?
B
2
, C
2
, N
2
, O
2
, F
2
A. B
2
and N
2
B. B
2
and O
2
C. N
2
and O
2
D. N
2
and F
2
E. C
2
, O
2
, and F
2
____ 50. What is the bond order for NO – ?
Form A, Page 16 of 17
____ 51. ***Calculate the lattice energy of magnesium sulfide from the data given below:***
Mg( s )  Mg( g )  H ° = 148 kJ/mol
Mg( g )  Mg
2+
( g ) + 2e
–
 H ° = 2186 kJ/mol
S
8
( s )  8S( g )  H ° = 2232 kJ/mol
S( g ) + 2e
–
 S
2–
( g )  H ° = 450 kJ/mol
8Mg( s ) + S
8
( s )  8MgS( s )  H ° = –2744 kJ/mol
Mg
2+
( g ) + S
2–
( g )  MgS( s )  H °
lattice
= ?