Use the Born–Haber cycle and data from Appendix IIB, Chapter 9 and this chapter to calculate the lattice energy of LiBr. (ΔHsub for lithium is 138 kJ>mol.)

Video transcript

Hi everyone here we have a question asking us to calculate the lattice energy of sodium bromide. So the lattice energy is going to equal the negative change in entropy of formation of sodium bromide solid plus the change in entropy of formation of sodium gashes plus the change in entropy of formation of bro. Mean gashes plus the first ionization energy of sodium plus the energy of roaming. So what are these values? The change in entropy? A formation of sodium bromide solid Equals negative 361.4 killed joules per mole. The change in entropy of formation of sodium gasses equals 108.8 kg joules per mole. The change in entropy of formation of bro. Ming gashes Equals 111.9 kg Permal. The first ionization energy of sodium Equals 496.0 killed joules per mole. And the energy of brow mean Equals -325.0 killed Jules Permal. So now let's plug this in. So the lattice energy is going to equal negative negative 361.4 kg joules per mole plus 108.8 kg joules per mole Plus 111 .9 kg per mole Plus 496. Kill jules Permal plus -325. Kill jules Permal. And that equals 753 . kg Permal. And that is our final answer. Thank you for watching. Bye