Question

The INCORRECT statement is:
1. Lithium is the strongest reducing agent among the alkali metals.
2. Lithium is least reactive with water among the alkali metals.
3. LiNO₃ decomposes on heating to give LiNO₂ and O₂.
4. LiCl crystallizes from aqueous solution as LiCl.2H₂O.

Answer 1

Correct Answer - Option 3 : LiNO₃ decomposes on heating to give LiNO₂ and O₂.

Concept:

Lithium nitrate decomposes into its oxide on heating. Upon thermal decomposition, LiNO₃ gives lithium oxide (Li₂ O), nitrogen dioxide (NO₂), and oxygen (O₂). LiNO₃ on heating gives reddish-brown fumes of NO₂.

\(4{\rm{LiN}}{{\rm{O}}_3}\mathop \to \limits^{\rm{\Delta }} 2{\rm{L}}{{\rm{i}}_2}{\rm{O}} + 4{\rm{N}}{{\rm{O}}_2} + {{\rm{O}}_2}\)

Other groups of nitrates decompose differently, forming the nitrate salt and oxygen. Because of its relatively small size, the lithium cation is very polarizing, which favors the formation of the oxide.

The other statements are true about lithium.

Hence the option (c) is correct.