Ch.9 - Bonding & Molecular StructureSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Lattice Energy

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Sections
Chemical Bonds
Lattice Energy
Lattice Energy Application
Born Haber Cycle
Dipole Moment
Lewis Dot Structure
Octet Rule
Formal Charge
Resonance Structures
Additional Sections
Percent Ionic Character
Bond Energy

Lattice Energy is the energy required to combine gaseous ions into a solid, crystalline structure. 

Examining Lattice Energy

Concept #1: Understanding Exergonic & Endergonic Reactions 

When dealing with the absorbing or releasing of energy in general then we use the terms endergonic & exergonic

Concept #2: Understanding Lattice Energy

Example #1: For each pair, choose the compound with the lower lattice energy.

a. BaO or MgO

b. LiCl  or  CaS

Practice: Choose the compound with the lower lattice energy.

Practice: Choose the compound with the higher lattice energy.

Additional Problems
Which is a FALSE statement? (A) The lattice energy of LiCl has a larger magnitude than that of NaCl. (B) The lattice energy of CaO has a larger magnitude than that of NaCl. (C) Na reacts with 1/2 Cl 2 to form NaCl molecules (D) Some ionic compounds may not conduct electricity when dissolved in water. (E) Lattice energy decreases as ionic radius increases as long as charge remains constant.
The lattice energy for ionic crystals decreases as the charge on the ions _____________ and the size of the ions __________________.  (a) increases, increases (b) increases, decreases (c) decreases, increases (d) decreases, decreases (e) None of these choices are correct.
Which of the following ionic bonds will have the greatest attraction? A. BeCl2 B. MgCl2 C. SrCl2 D. BaCl2
Consider the following ionic substances and arrange them in order of decreasing lattice energy. MgCl2            CaCl 2            MgF 2 A.  MgF2>CaCl2>MgCl2  B. MgF2>MgCl2>CaCl2 C. MgCl2>CaCl2>MgF2 D. CaCl2>MgF2>MgCl2 E. CaCl2>MgCl2>MgF2
Which of the following compounds would be expected to have the greatest lattice energy? a) SrO b) CsI c) NaBr d) MgO e) BaS
Which of the following reactions is associated with the  lattice energy of Li2O (ΔH°latt)? a) Li2O (s)  →  2 Li+ (g) + O2- (g) b) 2 Li+ (aq) + O2- (aq)  →   Li2O (s) c) 2 Li+ (g) + O2- (g) →    Li2O (s) d) Li2O (s) →   2 Li+ (aq) +  O2- (aq) e) 2 Li (s) + O2 (g) →  Li2O (s)
Which of the following has the highest lattice energy? NaCl KI MgO BaO CaO
Which of the following has the highest melting point? RbF KI KF KBr KCl
Predict the reaction associated with lattice energy, ΔHlat of BaS.
The lattice energy of calcium bromide is the energy change for the reaction 1. CaBr2(s) → Ca(g) + 2 Br(g) 2. Ca(s) + Br2(ℓ) → CaBr 2(s) 3. Ca(g) + 2 Br(g) → CaBr 2(g) 4. CaBr2(s) → Ca2+(g) + 2 Br−(g) 5. CaBr2(s) → Ca(g) + Br 2(g)
Which of the following solids would have the highest melting point? 1) NaI 2) NaF 3) MgO 4) MgCl2 5) KF
Choose the compound below that should have the highest melting or boiling point according to the ionic bonding model. AIN                                   MgO                                   NaF             
Which statement is a FALSE statement? a. The lattice energy of LiCl has a larger magnitude than that of NaCl. b. The lattice energy of CaO has a larger magnitude that that of NaCl. c. Na reacts with ½ Cl 2 to form NaCl molecules. d. Some ionic compounds may not conduct electricity when dissolved in water. e. Lattice energy decreases as ionic radius increases as long as charge remains constant.
Place the following in order of decreasing magnitude of lattice energy. KCl        MgO       RbI a. RbI > KCl > MgO b. RbI > MgO > KCl c. MgO > RbI > KCl d. MgO > KCl > RbI 
Which of the following compounds is expected to have the strongest ionic bond? a. MgO b. KBr c. NaI d. SrO e. CaS
Which of the following would have the highest melting point? 1. KF 2. KBr 3. Kl 4. KCl 5. RbF
The lattice enthalpy of calcium oxide is the energy change for the reaction 1. CaO(s) → Ca(g) + ½ O2(g) 2. Ca(g) + ½ O2(g) → CaO(s) 3. Ca(g) + O(g) → CaO(g) 4. CaO(s) → Ca2+(g) + O2- (g) 5. CaO(s) → Ca(g) + O(g)
If the following crystallize in the same type of structure, which has the highest lattice energy? 1. KF 2. KBr 3. KCl 4. LiF 5. LiCl
Which metal has the lowest melting point? a) Li b) Na c) K d) Rb
The solubilities of NaF and NaCl in water at 25°C are approximately 360 g/L H 2O and 80 g/L H2O respectively. Based on this information, which compound do you think has the larger lattice energy? 
Which of the following statements concerning lattice energy is false?a. The lattice energy for a solid with 2+ and 2- ions should be two times that for a solid with 1- and 1- ions. b. MgO has a larger lattice energy than NaF. c. MgO has a larger lattice energy than LiF. d. It is often defined as the energy released when an ionic solid forms from its ions. e. All of these are true.
Rank the following ionic compounds by the magnitude of their lattice energy. Rank from highest to lowest magnitude of lattice energy. LiCl, MgO, Na2O, BeO, Na2O
Rank this series of ionic compounds from smallest to largest magnitude (most exothermic) lattice energy:  NaCl         MgO        CaO       Al  2O3  a. NaCl < CaO < MgO < Al 2O3b. CaO < NaCl < MgO < Al 2O3c. Al2O3 < CaO < NaCl < MgOd. CaO < NaCl < Al 2O3 < MgOe. Al2O3 < NaCl < CaO < MgO 
A) Arrange the following substances in order of decreasing magnitude of lattice energy. CaO, NaF, SrO, KCl Rank from largest to smallest magnitude of lattice energy. B) Draw each molecule with their atoms and bonds NF3, HBr, SBr2, CCl4
Rank the compounds in order of decreasing magnitude of lattice energy. From Largest to Smallest BaO, KCl, CaO, RbBr
Place the following in order of Increasing magnitude of lattice energy.MgO NaL BaOa. Nal < MgO < Ba Ob.  MgO < Nal < Ba Oc. MgO < Ba O < Nald. Ba O < MgO < Nale. Nal < Ba O < MgO