The alkali metals dissolve in liquid ammonia without evolution of hydrogen. The metal loses electrons and combine with ammonia molecule.
$$M \to {M^ + }\left( {{\text{in liquid ammonia}}} \right)$$ $$ + {e^ - }\left( {{\text{ammoniated}}} \right)$$
$$M + \left( {x + y} \right)N{H_3} \to $$ $${\left[ {M{{\left( {N{H_3}} \right)}_x}} \right]^ + } + \mathop {{e^ - }{{\left( {N{H_3}} \right)}_y}}\limits_{{\text{Solvated electron }}} $$
152.
Based on lattice energy and other considerations, which one of the following alkali metal chloride is expected to have the highest melting point ?
$$NaCl$$ due it to its largest lattice energy has the highest melting point.
153.
Sodium is heated in air at $${300^ \circ }C$$ to form $$X.$$ $$X$$ absorbs $$C{O_2}$$ and forms $$N{a_2}C{O_3}$$ and $$Y.$$ Which of the following is $$Y?$$
Actually $$Li$$ is harder than other alkali metals.
156.
Nuclear attraction is often the deciding control factor for the association of neutral molecules to a given metal ion. Which one of the following represents the correct order of stability of the ions? $${\left[ {Be\left( {{H_2}{O_4}} \right)} \right]^{2 + }},{\left[ {Mg{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }},$$ $${\left[ {Ca{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }}\,{\text{and}}\,{\left[ {Sr{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }}$$
The degree of hydration and the amount of hydration energy decreases as the size of the ion increases from $$B{e^{2 + }}$$ to $$S{r^{2 + }}.$$
\[\underset{\begin{smallmatrix}
\text{Hydration} \\
\text{Energy}\left( kJ\,\,mo{{l}^{-1}} \right)
\end{smallmatrix}}{\mathop{{}}}\,\underset{-2494}{\mathop{B{{e}^{2+}}}}\,<\underset{-1921}{\mathop{M{{g}^{2+}}}}\,<\underset{-1577}{\mathop{C{{a}^{2+}}}}\,<\underset{-1443}{\mathop{S{{r}^{2+}}}}\,\]
$${\text{Thus, stability of hydrated ion is}}$$
$${\left[ {Be{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }} > {\left[ {Mg{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }}$$ $$ > {\left[ {Ca{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }} > {\left[ {Sr{{\left( {{H_2}O} \right)}_4}} \right]^{2 + }}$$
157.
A sodium salt on treatment with $$MgC{l_2}$$ gives white precipitate only on heating. The anion of the sodium salt is
158.
The metal $$X$$ is prepared by the electrolysis of fused chloride. It reacts with hydrogen to form a colourless solid from which hydrogen is released on treatment with water. The metal is :
159.
In the given chemical reactions, \[2P+{{H}_{2}}O+C{{O}_{2}}\to Q\xrightarrow{{{H}_{2}}O\,+\,C{{O}_{2}}}\] \[2R\xrightarrow{NaCl}S+N{{H}_{4}}Cl\]
Identify $$S.$$
The given equations are involved in Solvay process.
$$\mathop {2N{H_3}}\limits_{\left( P \right)} + {H_2}O + C{O_2} \to \mathop {{{\left( {N{H_4}} \right)}_2}C{O_3}}\limits_{\left( Q \right)} $$ \[\xrightarrow{{{H}_{2}}O\,+\,C{{O}_{2}}}\underset{\left( R \right)}{\mathop{2N{{H}_{4}}HC{{O}_{3}}}}\,\xrightarrow{NaCl}\] $$\mathop {NaHC{O_3}}\limits_{\left( S \right)} + N{H_4}Cl$$
160.
Match the column I with column II and mark the appropriate choice.