Question 1

Classify the Ca - Cl bond in CaCl2 as ionic, polar covalent, or nonpolar covalent.

Accepted Answer

A) ionic 
B) polar covalent 
C) nonpolar covalent 
A) ionic 
B) polar covalent 
C) nonpolar covalent

Question 2

The formal charge on the bromine atom in BrO3-  drawn with three single bonds is

Accepted Answer

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

Question 3

Dichloromethane, CH2Cl2, is an important solvent in synthetic chemistry.Write a Lewis structure for CH2Cl2.

Accepted Answer

Question 4

Use the bond enthalpy data given to estimate the heat released when 6.50 g of nitrogen gas reacts with excess hydrogen gas to form ammonia at 25°C. BE(N$\equiv$N)= 941.4 kJ/mol
BE(H-H)= 436.4 kJ/mol
BE(N-H)= 393 kJ/mol

Accepted Answer

A) 228 kJ 
B) 340 kJ 
C) 107 kJ 
D) 46.1 kJ 
E) 24.9 kJ 
A) 228 kJ 
B) 340 kJ 
C) 107 kJ 
D) 46.1 kJ 
E) 24.9 kJ

Question 5

Use the Born-Haber cycle to calculate the standard enthalpy of formation ($\Delta$H   )for LiCl(s)given the following data: $\Delta$H(sublimation)Li = 155.2 kJ/mol
I1 (Li)= 520 kJ/mol
Bond energy (Cl-Cl)= 242.7 kJ/mol
EA (Cl)= 349 kJ/mol
Lattice energy (LiCl(s))= 828 kJ/mol

Accepted Answer

A) 440 kJ/mol 
B) 320 kJ/mol 
C) -260 kJ/mol 
D) -380 kJ/mol 
E) -1420 kJ/mol 
A) 440 kJ/mol 
B) 320 kJ/mol 
C) -260 kJ/mol 
D) -380 kJ/mol 
E) -1420 kJ/mol

Question 6

Classify the O - H bond in CH3OH as ionic, polar covalent, or nonpolar covalent.

Accepted Answer

A) ionic 
B) polar covalent 
C) nonpolar covalent 
A) ionic 
B) polar covalent 
C) nonpolar covalent

Question 7

What is the formal charge on the oxygen atom in N2O (the atomic order is N-N-O)?

Accepted Answer

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

Question 8

The standard enthalpy of formation of ammonia at 25°C is -46.3 kJ/mol. Estimate the N-H bond enthalpy at this temperature. (Given: BE(N$\equiv$N)=941.4 kJ/mol, BE(H-H)= 436.4 kJ/mol)

Accepted Answer

A) 383 kJ/mol 
B) 475 kJ/mol 
C) 360 kJ/mol 
D) 391 kJ/mol 
E) 459 kJ/mol 
A) 383 kJ/mol 
B) 475 kJ/mol 
C) 360 kJ/mol 
D) 391 kJ/mol 
E) 459 kJ/mol

Question 9

A polar covalent bond would form in which one of the following pairs of atoms?

Accepted Answer

A) Cl - Cl 
B) Si - Si 
C) Ca - Cl 
D) Cr - Br 
E) P - Cl 
A) Cl - Cl 
B) Si - Si 
C) Ca - Cl 
D) Cr - Br 
E) P - Cl

Question 10

Which one of the following compounds does not follow the octet rule?

Accepted Answer

A) NF3 
B) CF4 
C) PF5 
D) AsH3 
E) HCl 
A) NF3 
B) CF4 
C) PF5 
D) AsH3 
E) HCl

Question 11

The azide ion, N3-, is very reactive although it is isoelectronic with the very stable CO2 molecule. This reactivity is reasonable inasmuch as

Accepted Answer

A) a Lewis structure cannot be written for the azide ion that has nitrogen formal charges of zero. 
B) there is no valid Lewis structure possible for the azide ion. 
C) there are resonance structures for azide ion but not for carbon dioxide. 
D) nitrogen cannot form multiple bonds. 
E) charged species always decompose in solution. 
A) a Lewis structure cannot be written for the azide ion that has nitrogen formal charges of zero. 
B) there is no valid Lewis structure possible for the azide ion. 
C) there are resonance structures for azide ion but not for carbon dioxide. 
D) nitrogen cannot form multiple bonds. 
E) charged species always decompose in solution.

Question 12

Estimate the enthalpy change for the reaction 2CO + O2 $\rarr$ 2CO2 given the following bond energies. BE(C$\equiv$O)= 1074 kJ/mol
BE(O=O)= 499 kJ/mol
BE(C=O)= 802 kJ/mol

Accepted Answer

A) +2380 kJ/mol 
B) +744 kJ/mol 
C) +1949 kJ/mol 
D) -561 kJ/mol 
E) -744 kJ/mol 
A) +2380 kJ/mol 
B) +744 kJ/mol 
C) +1949 kJ/mol 
D) -561 kJ/mol 
E) -744 kJ/mol

Question 13

The electron dot structure for AsCl3 shows

Accepted Answer

A) a total of 84 electron dots 
B) three single bonds and 10 lone pairs 
C) two single bonds, one double bond, and 9 lone pairs 
D) one single bond, two double bonds, and 8 lone pairs 
E) three single bonds and one lone pair 
A) a total of 84 electron dots 
B) three single bonds and 10 lone pairs 
C) two single bonds, one double bond, and 9 lone pairs 
D) one single bond, two double bonds, and 8 lone pairs 
E) three single bonds and one lone pair

Question 14

Consider the hypothetical element Z with electron-dot formula   Give the formula for the simplest compound this element forms with chlorine.

Accepted Answer

The answer of Consider the hypothetical element Z with electron-dot...

Question 15

A charge of 2+ is most likely to occur for an ion formed from an atom whose electron configuration is 1s22s22p63s23p4.

Accepted Answer

A) True 
 B)False

Question 16

Use the Born-Haber cycle to calculate the lattice energy of MgO (s)given the following data: $\Delta$H(sublimation)Mg = 130 kJ/mol
I1 (Mg)= 738.1 kJ/mol
I2 (Mg)= 1450 kJ/mol
Bond energy (O=O)= 498.7 kJ/mol
EA (O)= 141 kJ/mol
EA (O-)= -780 kJ/mol
$\Delta$H   (MgO(s))= -601.8 kJ/mol

Accepted Answer

A) 2200 kJ/mol 
B) 2800 kJ/mol 
C) 3200 kJ/mol 
D) 3800 kJ/mol 
E) 4100 kJ/mol 
A) 2200 kJ/mol 
B) 2800 kJ/mol 
C) 3200 kJ/mol 
D) 3800 kJ/mol 
E) 4100 kJ/mol

Question 17

Calculate the energy required for the gas phase process represented by
Na(g)+ Br(g)$\rarr$Na+(g)+ Br - (g)

Accepted Answer

The answer of Calculate the energy required for the gas...

Question 18

Which of the following ionic solids would have the largest lattice energy?

Accepted Answer

A) SrO 
B) NaF 
C) CaBr2 
D) CsI 
E) BaSO4 
A) SrO 
B) NaF 
C) CaBr2 
D) CsI 
E) BaSO4

Question 19

Assuming the octet rule is obeyed, how many covalent bonds will an oxygen atom form to give a formal charge of zero?

Accepted Answer

A) 0 
B) 1 
C) 2 
D) 3 
E) 4 
A) 0 
B) 1 
C) 2 
D) 3 
E) 4

Question 20

Which of the following pairs of elements would be most likely to form an ionic compound?

Accepted Answer

A) Cl and I 
B) Al and K 
C) Cl and Mg 
D) C and S 
E) Al and Mg 
A) Cl and I 
B) Al and K 
C) Cl and Mg 
D) C and S 
E) Al and Mg

Exam 9: Chemical Bonding I: Basic Concepts

Classify the Ca - Cl bond in CaCl2 as ionic, polar covalent, or nonpolar covalent.

The formal charge on the bromine atom in BrO3- drawn with three single bonds is

Dichloromethane, CH2Cl2, is an important solvent in synthetic chemistry.Write a Lewis structure for CH2Cl2.

Use the bond enthalpy data given to estimate the heat released when 6.50 g of nitrogen gas reacts with excess hydrogen gas to form ammonia at 25°C. BE(N ≡\equiv≡ N)= 941.4 kJ/mol BE(H-H)= 436.4 kJ/mol BE(N-H)= 393 kJ/mol

Use the Born-Haber cycle to calculate the standard enthalpy of formation ( Δ\DeltaΔ H )for LiCl(s)given the following data: Δ\DeltaΔ H(sublimation)Li = 155.2 kJ/mol I1 (Li)= 520 kJ/mol Bond energy (Cl-Cl)= 242.7 kJ/mol EA (Cl)= 349 kJ/mol Lattice energy (LiCl(s))= 828 kJ/mol

Classify the O - H bond in CH3OH as ionic, polar covalent, or nonpolar covalent.

What is the formal charge on the oxygen atom in N2O (the atomic order is N-N-O)?

The standard enthalpy of formation of ammonia at 25°C is -46.3 kJ/mol. Estimate the N-H bond enthalpy at this temperature. (Given: BE(N ≡\equiv≡ N)=941.4 kJ/mol, BE(H-H)= 436.4 kJ/mol)

A polar covalent bond would form in which one of the following pairs of atoms?

Which one of the following compounds does not follow the octet rule?

The azide ion, N3-, is very reactive although it is isoelectronic with the very stable CO2 molecule. This reactivity is reasonable inasmuch as

Estimate the enthalpy change for the reaction 2CO + O2 →\rarr→ 2CO2 given the following bond energies. BE(C ≡\equiv≡ O)= 1074 kJ/mol BE(O=O)= 499 kJ/mol BE(C=O)= 802 kJ/mol

The electron dot structure for AsCl3 shows

Consider the hypothetical element Z with electron-dot formula Give the formula for the simplest compound this element forms with chlorine.

A charge of 2+ is most likely to occur for an ion formed from an atom whose electron configuration is 1s22s22p63s23p4.

Use the Born-Haber cycle to calculate the lattice energy of MgO (s)given the following data: Δ\DeltaΔ H(sublimation)Mg = 130 kJ/mol I1 (Mg)= 738.1 kJ/mol I2 (Mg)= 1450 kJ/mol Bond energy (O=O)= 498.7 kJ/mol EA (O)= 141 kJ/mol EA (O-)= -780 kJ/mol Δ\DeltaΔ H (MgO(s))= -601.8 kJ/mol

Calculate the energy required for the gas phase process represented by Na(g)+ Br(g) →\rarr→ Na+(g)+ Br - (g)

Which of the following ionic solids would have the largest lattice energy?

Assuming the octet rule is obeyed, how many covalent bonds will an oxygen atom form to give a formal charge of zero?

Which of the following pairs of elements would be most likely to form an ionic compound?

Chemistry: The Study of Change

Atoms, Molecules, and Ions

Mass Relationships in Chemical Reactions

Reactions in Aqueous Solution

Gases

Thermo-Chemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Chemistry in the Atmosphere

Entropy, Free Energy, and Equilibrium

Electrochemistry

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Nuclear Chemistry

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

Classify the Ca - Cl bond in CaCl₂ as ionic, polar covalent, or nonpolar covalent.

The formal charge on the bromine atom in BrO₃^- drawn with three single bonds is

Dichloromethane, CH₂Cl₂, is an important solvent in synthetic chemistry.Write a Lewis structure for CH₂Cl₂.

Use the bond enthalpy data given to estimate the heat released when 6.50 g of nitrogen gas reacts with excess hydrogen gas to form ammonia at 25°C. BE(N $\equiv$ N)= 941.4 kJ/mol BE(H-H)= 436.4 kJ/mol BE(N-H)= 393 kJ/mol

Classify the O - H bond in CH₃OH as ionic, polar covalent, or nonpolar covalent.

What is the formal charge on the oxygen atom in N₂O (the atomic order is N-N-O)?

The standard enthalpy of formation of ammonia at 25°C is -46.3 kJ/mol. Estimate the N-H bond enthalpy at this temperature. (Given: BE(N $\equiv$ N)=941.4 kJ/mol, BE(H-H)= 436.4 kJ/mol)

The azide ion, N₃^-, is very reactive although it is isoelectronic with the very stable CO₂ molecule. This reactivity is reasonable inasmuch as

Estimate the enthalpy change for the reaction 2CO + O₂ $\rarr$ 2CO₂ given the following bond energies. BE(C $\equiv$ O)= 1074 kJ/mol BE(O=O)= 499 kJ/mol BE(C=O)= 802 kJ/mol

The electron dot structure for AsCl₃ shows

A charge of 2+ is most likely to occur for an ion formed from an atom whose electron configuration is 1s²2s²2p⁶3s²3p⁴.

Calculate the energy required for the gas phase process represented by Na(g)+ Br(g) $\rarr$ Na⁺(g)+ Br^-(g) $Calculate the energy required for the gas phase process represented by Na(g)+ Br(g) \rarr Na<sup>+</sup>(g)+ Br<sup> - </sup>(g)$