Question

Explain why the quantitative value for the lattice enthalpy of calcium bromide is larger than the value for the lattice enthalpy of potassium bromide.

Answer 1

Answer:

Explanation:

We define lattice energy as "the change in internal energy that accompanies the formation of one mole of the solid from its constituent gas phase ions." (Housecroeft and Sharpe, 2012).

Also, lattice energy depends on the size of the ions. In this case, the anion is the same so we consider the relative sizes of the cations. The smaller the size of the cation, the greater the quantitative value of the lattice energy.

Since Ca^2+ is smaller than K^+, the quantitative value for the lattice enthalpy of calcium bromide is larger than the value for the lattice enthalpy of potassium bromide.