Question 1

Which of the following statements correctly describe the basic concepts and uses of VSEPR theory: 
I. The VSEPR theory is used for estimating bond angles.
II. The VSEPR theory is used for predicting electronegativities.
III. The VSEPR theory is helpful in predicting polarity.
IV. The VSEPR theory states that electron pairs repel each other.
V.The VSEPR theory uses valence electron counting for structure prediction.

Accepted Answer

A)  I), II), III), IV) 
B)  I), II), IV), V) 
C)  I), II), III), V) 
D)  II), III), IV), V) 
E)  I), III), IV), V)

Question 2

Given the bond enthalpies Cl-Cl (243), C-Cl (339), H-Cl (431),C-H (414) all in kJ/mol, estimate ΔH for the following reaction: CH4(g) + Cl2(g) → CH3Cl(g) + HCl(g)

Accepted Answer

A)  -113 kJ 
B)  -356 kJ 
C)  301 kJ 
D)  -1427 kJ 
E)  -30 kJ

Question 3

Valence electrons are:

Accepted Answer

A)  all electrons of the last rare gas configuration 
B)  electrons in filled orbits 
C)  electrons in the shell of the highest principal quantum number 
D)  unpaired electrons 
E)  paired electrons

Question 4

After drawing the Lewis dot structure for CH3Cl, determine the number of single bonds, double bonds, and lone pairs on the central atom.

Accepted Answer

A)  4, 1, 0 
B)  4, 0, 1 
C)  3, 0, 1 
D)  4, 0, 0 
E)  3, 1, 0

Question 5

After drawing the Lewis dot structure of HCN, pick the INCORRECT statement from the following.

Accepted Answer

A)  The C-N bond is a double bond. 
B)  There are no lone pairs on C. 
C)  The C-H bond is a single bond. 
D)  There is a lone pair of electrons on N. 
E)  There are no lone pairs on H.

Question 6

Which of the following must be paramagnetic?

Accepted Answer

A)  F2 
B)  N2 
C)  SO2+ 
D)  H2 
E)  ClO2-

Question 7

A Lewis structure is a combination of Lewis symbols representing either the transfer or the sharing of electrons in a chemical bond.

Accepted Answer

A) True 
 B)False

Question 8

What is the correct molecular geometry for silicon atom in disilane Si2H6?

Accepted Answer

A)  Tetrahedral 
B)  Square planar 
C)  Octahedral 
D)  Linear 
E)  Bent

Question 9

Write a Lewis structure for sodium iodide.

Accepted Answer

A)   
B)   
C)   
D)  Na- I 
E)

Question 10

Which of the following molecules is nonpolar?

Accepted Answer

A)  HCN 
B)  CHCl3 
C)  H2O 
D)  HClO4 
E)  BCl3

Question 11

Which of the following species contains a triple bond?

Accepted Answer

A)  NH3 
B)  HCCl3 
C)  NO3- 
D)  CO32- 
E)  CN-

Question 12

In a Lewis structure, a terminal atom is bonded to two or more atoms.

Accepted Answer

A) True 
 B)False

Question 13

What is the formal charge on N in NO3-?

Accepted Answer

A)  +2 
B)  -2 
C)  +1 
D)  -1 
E)  0

Question 14

Choose the correct statement about the compound SO2.

Accepted Answer

A)  The S atom has an unshared electron pair. 
B)  The S-O bonds are ionic in character. 
C)  The two S-O bonds have different lengths since one is a single bond and the other a double bond. 
D)  The molecule has a linear structure. 
E)  The O atoms have no unshared electron pairs.

Question 15

Compound EX4 reacts with Y2 giving two products: EX3Y and XY. Calculate the E-X bond enthalpy if the reaction liberates 243.6 kJ/mol and other bond enthalpies are: Y-Y 109 kJ/mol, X-Y 123.1 kJ/mol and E-Y 290 kJ/mol.

Accepted Answer

A)  60.5 kJ/mol 
B)  547.7 kJ/mol 
C)  20.6 kJ/mol 
D)  234.7 kJ/mol 
E)  176.9 kJ/mol

Question 16

Write a Lewis structure for BaO.

Accepted Answer

A)   
B)   
C)   
D)  [Ba-O] 
E)

Question 17

Write a Lewis structure for barium fluoride.

Accepted Answer

A)   
B)  F-B-F 
C)   
D)   
E)

Question 18

Given the bond enthalpies I-Cl (209), H-H (435), H-I (297), and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for: ICl3(g) + 2 H2(g) → HI(g) + 3 HCl(g)

Accepted Answer

A)  +264 
B)  -84 
C)  -93 
D)  -523 
E)  +84

Question 19

Which of the following has a molecular structure best described as involving an "incomplete octet"?

Accepted Answer

A)  OF2 
B)  BF3 
C)  CF4 
D)  NF3 
E)  F2

Question 20

Which compound would be expected to have the shortest carbon-carbon bond?

Accepted Answer

A)  H3CCH3 
B)  HCCH 
C)  H2CCH2 
D)  F3CCF3 
E)  Cl2CCCl2

Exam 10: Chemical Bonding I: Basic Concepts

Given the bond enthalpies Cl-Cl (243) , C-Cl (339) , H-Cl (431) ,C-H (414) all in kJ/mol, estimate ΔH for the following reaction: CH₄(g) + Cl₂(g) → CH₃Cl(g) + HCl(g)

Valence electrons are:

After drawing the Lewis dot structure for CH₃Cl, determine the number of single bonds, double bonds, and lone pairs on the central atom.

After drawing the Lewis dot structure of HCN, pick the INCORRECT statement from the following.

Which of the following must be paramagnetic?

A Lewis structure is a combination of Lewis symbols representing either the transfer or the sharing of electrons in a chemical bond.

What is the correct molecular geometry for silicon atom in disilane Si₂H₆?

Write a Lewis structure for sodium iodide.

Which of the following molecules is nonpolar?

Which of the following species contains a triple bond?

In a Lewis structure, a terminal atom is bonded to two or more atoms.

What is the formal charge on N in NO₃^-?

Choose the correct statement about the compound SO₂.

Compound EX4 reacts with Y2 giving two products: EX3Y and XY. Calculate the E-X bond enthalpy if the reaction liberates 243.6 kJ/mol and other bond enthalpies are: Y-Y 109 kJ/mol, X-Y 123.1 kJ/mol and E-Y 290 kJ/mol.

Write a Lewis structure for BaO.

Write a Lewis structure for barium fluoride.

Given the bond enthalpies I-Cl (209) , H-H (435) , H-I (297) , and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for: ICl₃(g) + 2 H₂(g) → HI(g) + 3 HCl(g)

Which of the following has a molecular structure best described as involving an "incomplete octet"?

Which compound would be expected to have the shortest carbon-carbon bond?

Exam 10: Chemical Bonding I: Basic Concepts

Given the bond enthalpies Cl-Cl (243) , C-Cl (339) , H-Cl (431) ,C-H (414) all in kJ/mol, estimate ΔH for the following reaction: CH4(g) + Cl2(g) → CH3Cl(g) + HCl(g)

Valence electrons are:

After drawing the Lewis dot structure for CH3Cl, determine the number of single bonds, double bonds, and lone pairs on the central atom.

After drawing the Lewis dot structure of HCN, pick the INCORRECT statement from the following.

Which of the following must be paramagnetic?

A Lewis structure is a combination of Lewis symbols representing either the transfer or the sharing of electrons in a chemical bond.

What is the correct molecular geometry for silicon atom in disilane Si2H6?

Write a Lewis structure for sodium iodide.

Which of the following molecules is nonpolar?

Which of the following species contains a triple bond?

In a Lewis structure, a terminal atom is bonded to two or more atoms.

What is the formal charge on N in NO3-?

Choose the correct statement about the compound SO2.

Compound EX4 reacts with Y2 giving two products: EX3Y and XY. Calculate the E-X bond enthalpy if the reaction liberates 243.6 kJ/mol and other bond enthalpies are: Y-Y 109 kJ/mol, X-Y 123.1 kJ/mol and E-Y 290 kJ/mol.

Write a Lewis structure for BaO.

Write a Lewis structure for barium fluoride.

Given the bond enthalpies I-Cl (209) , H-H (435) , H-I (297) , and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for: ICl3(g) + 2 H2(g) → HI(g) + 3 HCl(g)

Which of the following has a molecular structure best described as involving an "incomplete octet"?

Which compound would be expected to have the shortest carbon-carbon bond?

Given the bond enthalpies Cl-Cl (243) , C-Cl (339) , H-Cl (431) ,C-H (414) all in kJ/mol, estimate ΔH for the following reaction: CH₄(g) + Cl₂(g) → CH₃Cl(g) + HCl(g)

After drawing the Lewis dot structure for CH₃Cl, determine the number of single bonds, double bonds, and lone pairs on the central atom.

What is the correct molecular geometry for silicon atom in disilane Si₂H₆?

What is the formal charge on N in NO₃^-?

Choose the correct statement about the compound SO₂.

Given the bond enthalpies I-Cl (209) , H-H (435) , H-I (297) , and H-Cl (431) in kJ/mol, compute ΔH° in kJ/mol for: ICl₃(g) + 2 H₂(g) → HI(g) + 3 HCl(g)