Question 1

Valence electrons are:

Accepted Answer

A) all electrons of the last noble gas configuration 
B) electrons in filled orbits 
C) electrons in the shell of the highest principal quantum number 
D) unpaired electrons 
E) paired electrons 
A) all electrons of the last noble 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 2

Write a Lewis structure for calcium hydride.

Accepted Answer

A)    
B)    
C)    
D)  H-Ca-H 
E)  Ca-H 
A)    
B)    
C)    
D)  H-Ca-H 
E)  Ca-H

Question 3

Choose the INCORRECT statement.

Accepted Answer

A) A Lewis symbol consists of a chemical symbol and the outer shell electrons. 
B) In a Lewis symbol,the chemical symbol represents the nucleus of the atom. 
C) A Lewis structure is a combination of Lewis symbols that represent the transfer or sharing of electrons in a chemical bond. 
D) An ion written as a Lewis symbol has brackets outside the electrons. 
E) An ion written as a Lewis symbol has the charge written as a superscript outside the closing bracket. 
A) A Lewis symbol consists of a chemical symbol and the outer shell electrons. 
B) In a Lewis symbol,the chemical symbol represents the nucleus of the atom. 
C) A Lewis structure is a combination of Lewis symbols that represent the transfer or sharing of electrons in a chemical bond. 
D) An ion written as a Lewis symbol has brackets outside the electrons. 
E) An ion written as a Lewis symbol has the charge written as a superscript outside the closing bracket.

Question 4

Given the bond enthalpies H-O (464),Cl-Cl (243),Cl-O (205),and H-Cl (431)in kJ/mol,compute ΔH° in kJ/mol for: 
H2O(g)+ Cl2(g)→ HOCl(g)+ HCl(g).

Accepted Answer

A) -393 kJ/mol 
B) -1100 kJ/mol 
C) +71 kJ/mol 
D) +393 kJ/mol 
E) +1100 kJ/mol 
A) -393 kJ/mol 
B) -1100 kJ/mol 
C) +71 kJ/mol 
D) +393 kJ/mol 
E) +1100 kJ/mol

Question 5

What is the molecular shape of BrF5?

Accepted Answer

A) linear 
B) square pyramidal 
C) square planar 
D) octahedral 
E) trigonal bipyramidal 
A) linear 
B) square pyramidal 
C) square planar 
D) octahedral 
E) trigonal bipyramidal

Question 6

After drawing the Lewis dot structure for BeCl2,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

Accepted Answer

A) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 0 
B) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 2 
C) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 1 
D) single bond(s)= 0,double bond(s)= 2,lone pair(s)= 0 
E) single bond(s)= 1,double bond(s)= 1,lone pair(s)= 0 
A) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 0 
B) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 2 
C) single bond(s)= 2,double bond(s)= 0,lone pair(s)= 1 
D) single bond(s)= 0,double bond(s)= 2,lone pair(s)= 0 
E) single bond(s)= 1,double bond(s)= 1,lone pair(s)= 0

Question 7

The core electrons are called valence electrons.

Accepted Answer

A) True 
 B)False

Question 8

How many "dots" should be shown for the oxygen symbol in lithium oxide?

Accepted Answer

A) 2 
B) 4 
C) 6 
D) 8 
E) 10 
A) 2 
B) 4 
C) 6 
D) 8 
E) 10

Question 9

An expanded octet may occur:

Accepted Answer

A) in the 1st and 2nd period only 
B) in families IA,IIA,and IIIA only 
C) anywhere except period 1 and 2 
D) in all families except IA 
E) in the 3rd and 4th period only 
A) in the 1st and 2nd period only 
B) in families IA,IIA,and IIIA only 
C) anywhere except period 1 and 2 
D) in all families except IA 
E) in the 3rd and 4th period only

Question 10

Write a Lewis structure for sodium iodide.

Accepted Answer

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

Question 11

After drawing the Lewis dot structure for IF7,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

Accepted Answer

A) single bond(s)= 3,double bond(s)= 2,lone pair(s)= 1 
B) single bond(s)= 7,double bond(s)= 0,lone pair(s)= 1 
C) single bond(s)= 7,double bond(s)= 0,lone pair(s)= 0 
D) single bond(s)= 1,double bond(s)= 0,lone pair(s)= 0 
E) single bond(s)= 4,double bond(s)= 0,lone pair(s)= 0 
A) single bond(s)= 3,double bond(s)= 2,lone pair(s)= 1 
B) single bond(s)= 7,double bond(s)= 0,lone pair(s)= 1 
C) single bond(s)= 7,double bond(s)= 0,lone pair(s)= 0 
D) single bond(s)= 1,double bond(s)= 0,lone pair(s)= 0 
E) single bond(s)= 4,double bond(s)= 0,lone pair(s)= 0

Question 12

The compound ClF  contains:

Accepted Answer

A) ionic bonds 
B) nonpolar covalent bonds 
C) polar covalent bonds with partial negative charges on the F atoms 
D) polar covalent bonds with partial negative charges on the Cl atoms 
A) ionic bonds 
B) nonpolar covalent bonds 
C) polar covalent bonds with partial negative charges on the F atoms 
D) polar covalent bonds with partial negative charges on the Cl atoms

Question 13

How many lone pairs of electrons are on the As atom in AsCl3?

Accepted Answer

A) 0 
B) 1 
C) 2 
D) 3 
A) 0 
B) 1 
C) 2 
D) 3

Question 14

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

Question 15

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. 
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 16

What is the formal charge on N in NO3-?

Accepted Answer

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

Question 17

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 
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 18

What is the correct molecular geometry for the carbon atom in urea (NH2)2CO?

Accepted Answer

A) Tetrahedral 
B) T-Shaped 
C) Trigonal planar 
D) Trigonal pyramidal 
E) Trigonal bipyramidal 
A) Tetrahedral 
B) T-Shaped 
C) Trigonal planar 
D) Trigonal pyramidal 
E) Trigonal bipyramidal

Question 19

How many bond pairs ("bp")and how many lone pairs ("lp")should be shown in the Lewis structure for carbon monoxide?

Accepted Answer

A) 1 bp/4 lp 
B) 2 bp/3 lp 
C) 3 bp/2 lp 
D) 4 bp/1 lp 
E) 5 bp/0 lp 
A) 1 bp/4 lp 
B) 2 bp/3 lp 
C) 3 bp/2 lp 
D) 4 bp/1 lp 
E) 5 bp/0 lp

Question 20

Which of the following exhibits ionic bonding?

Accepted Answer

A) C2H6  
B) Na2S 
C) H2CO 
D) SiCl4  
E) SF4 
A) C2H6  
B) Na2S 
C) H2CO 
D) SiCl4  
E) SF4

Exam 10: Chemical Bonding I: Basic Concepts

Valence electrons are:

Write a Lewis structure for calcium hydride.

Choose the INCORRECT statement.

Given the bond enthalpies H-O (464),Cl-Cl (243),Cl-O (205),and H-Cl (431)in kJ/mol,compute ΔH° in kJ/mol for: H2O(g)+ Cl2(g)→ HOCl(g)+ HCl(g).

What is the molecular shape of BrF5?

After drawing the Lewis dot structure for BeCl2,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

The core electrons are called valence electrons.

How many "dots" should be shown for the oxygen symbol in lithium oxide?

An expanded octet may occur:

Write a Lewis structure for sodium iodide.

After drawing the Lewis dot structure for IF7,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

The compound ClF contains:

How many lone pairs of electrons are on the As atom in AsCl3?

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).

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

What is the formal charge on N in NO3-?

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.

What is the correct molecular geometry for the carbon atom in urea (NH2)2CO?

How many bond pairs ("bp")and how many lone pairs ("lp")should be shown in the Lewis structure for carbon monoxide?

Which of the following exhibits ionic bonding?

Matter: Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding Ii: Valence Bond and Molecular Orbital Theories

Intermolecular Forces: Liquids and Solids

Spontaneous Change: Entropy and Gibbs Energy

Solutions and Their Physical Properties

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acidbase Equilibria

Solubility and Complex-Ion Equilibria

Electrochemistry

Chemical Kinetics

Chemistry of the Main-Group Elements I: Groups 1,2,13,and 14

Chemistry of the Main-Group Elements Ii: Groups 18,17,16,15,and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

Given the bond enthalpies H-O (464),Cl-Cl (243),Cl-O (205),and H-Cl (431)in kJ/mol,compute ΔH° in kJ/mol for: H₂O(g)+ Cl₂(g)→ HOCl(g)+ HCl(g).

What is the molecular shape of BrF₅?

After drawing the Lewis dot structure for BeCl_2,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

After drawing the Lewis dot structure for IF_7,determine the number of single bond(s),double bond(s),and lone pair(s)on the central atom.

How many lone pairs of electrons are on the As atom in AsCl₃?

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).

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

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.

What is the correct molecular geometry for the carbon atom in urea (NH₂)₂CO?