Points of Difference between Lithium and Other Alkali Metals
- Lithium is much harder, its m.pt. and b.pt. are higher than the other alkali metals
- Lithium is the least reactive but the strongest reducing agent among all the alkali metals. On combustion in air it forms mainly monoxide Li2O, and the nitride, Li3N unlike other alkali metals.
- LiCl is deliquescent and crystallizes as a hydrate. LiCl.2H2O, whereas other alkali metal chlorides do not from hydrates. Lithium bicarbonate is not obtained in the solid form while all other elements of this group form solid bicarbonates. Lithium, unlike alkali metals, forms no acetylide on reaction with ethyne.
- Lithium nitrate when heated gives lithium oxide Li2O, whereas other alkali metal nitrates decompose to give the corresponding nitrite.
4LiNO3 2Li2O + 4NO2 + O2
2NaNO3 2NaNO2 + O2
- LiF and Li2O are comparatively much less soluble in water than the corresponding compounds of other alkali metals.