To calculate the lattice energy of sodium chloride NaCl , we can use the Coulomb's Law formula:Lattice Energy = k * q1 * q2 / rwhere:k = Coulomb's constant 8.9875517923 10^9 N m^2 C^-2 q1 = charge on the sodium ion +1 q2 = charge on the chloride ion -1 r = distance between the ions 2.82 First, we need to convert the distance from angstroms to meters m :1 = 1 10^-10 m2.82 = 2.82 10^-10 mNow, we can plug in the values into the formula:Lattice Energy = 8.9875517923 10^9 N m^2 C^-2 * +1 C * -1 C / 2.82 10^-10 m Lattice Energy = -8.9875517923 10^9 N m^2 C^-2 / 2.82 10^-10 mLattice Energy = -3.189 10^9 N m C^-2The lattice energy of sodium chloride NaCl is approximately -3.189 10^9 N m C^-2. Note that the negative sign indicates that the energy is released when the ions come together to form the lattice structure.