(a) The crystalline product from reaction 11.22 contains [Na₂]²⁻ units. Construct an MO diagram for [Na₂]²⁻ and determine the bond order in this species. Comment on the result in the light of the text discussion of this species, explaining differences between the MO model and the experimental data.

(b) The enthalpies of hydration for Na⁺, K⁺ and Rb⁺ are −404, −321 and −296 kJ mol⁻¹ respectively. Suggest an explanation for this trend.

Transcribed Image Text:

2+ Ba+Na+11.3 [Ba²+(11.3 - H)¯]Na™ (11.3 - H) = deprotonated ligand 11.3 (11.22)