(a) Na 3 N remained an elusive compound until 2002 Calculate a value for f H o (Na 3 N, s) using data from Appendices 8 and 10, and the following estimated values of H(298 K) Comment on whether the value obtained is sufficient to indicate whether Na 3 N is thermodynamically stable (b) The high temp...

a To calculate the standard molar enthalpy of formation fHo of Na3N sodium nitride we can use Hesss ...

(a) Na 3 N remained an elusive compound until 2002. Calculate a value for f H...

Question:

(a) Na₃N remained an elusive compound until 2002. Calculate a value for Δ_fH^o(Na₃N, s) using data from Appendices 8 and 10, and the following estimated values of ΔH(298 K):

Comment on whether the value obtained is sufficient to indicate whether Na₃N is thermodynamically stable.

(b) The high-temperature crystalline form of RbNH₂ adopts a structure with a ccp array of [NH₂]‾ ions and Rb⁺ ions occupying octahedral sites. To which structure type does this correspond? Sketch a unit cell of RbNH₂ and confirm the stoichiometry of the compound by considering the number of ions per unit cell.