![]() ![]() Replacing r 0 as before yields the full Kapustinskii equation. The derivation of the later form of the Kapustinskii equation followed similar logic, starting from the quantum chemical treatment in which the final term is 1 − d / r 0 where d is as defined above. Finally, Kapustinskii noted that the Madelung constant, M, was approximately 0.88 times the number of ions in the empirical formula. ![]() Q1 Q 1 and Q2 Q 2 are the relative charges of the ions that make up an ionic compound. The formula for lattice energy is as follows: LE kQ1Q2 r L E k Q 1 Q 2 r. Born-Lande Equation: The Born-Lande equation is a means of calculating the lattice energy of a crystalline ionic compound. The lattice energy of an ionic compound depends on the charge and size of the ion. In addition, the Born exponent, n, was assumed to have a mean value of 9. Theoratical Calculation of Lattice Energy: 1. Kapustinskii replaced r 0, the measured distance between ions, with the sum of the corresponding ionic radii. It is named after Anatoli Fedorovich Kapustinskii who published the formula in 1956. ![]() A more typical exam question will ask you to compare the lattice energies between two. The Kapustinskii equation calculates the lattice energy U L for an ionic crystal, which is experimentally difficult to determine. Lattice Energy is always negative This is because the gaseous ions are less stable than the ionic solid that they form. On an exam, it is very unlikely that you would see a question that asks you to calculate the lattice energy. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |