Question

For each of the following, write an equation that corresponds to the energy given. a. lattice energy of \(\mathrm{NaCl}\) b. lattice energy of \(\mathrm{NH}_{4} \mathrm{Br}\) c. lattice energy of \(\mathrm{MgS}\) d. \(\mathrm{O}=\mathrm{O}\) double bond energy beginning with \(\mathrm{O}_{2}(g)\) as a reactant

Short answer

The equations representing the energy for each compound or bond are as follows: a. Lattice energy of NaCl: \(Na(s) + \frac{1}{2} Cl_{2}(g) \rightarrow NaCl(s)\) b. Lattice energy of NH4Br: \(N_{2}(g) + 4 H_{2}(g) + Br_{2}(l) \rightarrow 2 NH_{4}Br(s)\) c. Lattice energy of MgS: \(Mg(s) + S(s) \rightarrow MgS(s)\) d. O=O double bond energy beginning with O2(g) as a reactant: \(\mathrm{O}_{2}(g) \rightarrow 2 O(g)\)

Step-by-step solution

a. Lattice energy of NaCl

To write an equation for the lattice energy of NaCl, follow the Born-Haber cycle: 1. Start with the elements in their standard states: Na(s) + 1/2 Cl2(g) 2. Convert the elements into gaseous atoms: Na(g) + Cl(g) 3. Ionize the atoms: Na+(g) + Cl-(g) 4. Combine ions to form an ionic lattice (NaCl) The overall equation representing the lattice energy of NaCl is: \(Na(s) + \frac{1}{2} Cl_{2}(g) \rightarrow NaCl(s)\)

b. Lattice energy of NH4Br

To write an equation for the lattice energy of NH4Br, follow the Born-Haber cycle: 1. Start with the elements in their standard states: N2(g) + 4 H2(g) + Br2(l) 2. Form ammonia and hydrogen bromide: 2 NH3(g) + 2 HBr(g) 3. Convert ammonia to ammonium ion: 2 NH4+(g) 4. Combine ions to form an ionic lattice (NH4Br) The overall equation representing the lattice energy of NH4Br is: \(N_{2}(g) + 4 H_{2}(g) + Br_{2}(l) \rightarrow 2 NH_{4}Br(s)\)

c. Lattice energy of MgS

To write an equation for the lattice energy of MgS, follow the Born-Haber cycle: 1. Start with the elements in their standard states: Mg(s) + S(s) 2. Convert the elements into gaseous atoms: Mg(g) + S(g) 3. Ionize the atoms: Mg2+(g) + S2-(g) 4. Combine ions to form an ionic lattice (MgS) The overall equation representing the lattice energy of MgS is: \(Mg(s) + S(s) \rightarrow MgS(s)\)

d. O=O double bond energy beginning with O2(g) as a reactant

To write an equation for the double bond energy (bond enthalpy) of the O=O bond when starting with O2(g) as a reactant, we need to break the double bond between the oxygen atoms. The overall equation representing the double bond energy is: \(\mathrm{O}_{2}(g) \rightarrow 2 O(g)\)