9.6A: Physical Properties
- Page ID
- 33835
Despite low boiling point (-33.4 ºC), easy to handle.
Solubilities, relatively high dielectric constant (ammonia, eo= 26.7 @ -60ºC; water, eo = 82 @ 18 ºC).
Hence, ionic compounds can be soluble but the lower eo compared to water means that salt with highly charged, non-polarisable anions such as carbonates, sulphates, and phosphates are insoluble.
NH3 is more polarizable than H2O, so salts with more polarizable anions are more soluble, hence the solubility trends.
\[\ce{ F- < Cl- < Br- < I-}\]
\[\ce{PO43- < SO42- < OAc- < NO3}\]
specific solvation
NH3 is a better a-donor than H2O and ammine complexes are formed, especially with the later transition (Ni2+, Cu2+) and B metals (Ag+, Zn2+). Hence higher solubilities for compounds of these metals than those of the A-metals.