S - Block Elements MCQ Questions & Answers in Inorganic Chemistry | Chemistry
Learn S - Block Elements MCQ questions & answers in Inorganic Chemistry are available for students perparing for IIT-JEE, NEET, Engineering and Medical Enternace exam.
151.
The metallic sodium disolves in liquid ammonia to form a deep blue coloured solution. The deep blue colour is due to formation of :
A
solvated electron, $$e\left( {N{H_3}} \right)_x^ - $$
B
solvated atomic sodium, $$Na{\left( {N{H_3}} \right)_y}$$
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 ?
A
$$NaCl$$
B
$$KCl$$
C
$$LiCl$$
D
$$RbCl$$
Answer :
$$NaCl$$
$$NaCl$$ 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 $$Y?$$
A
$${H_2}$$
B
$${O_2}$$
C
$${H_2}{O_2}$$
D
$${O_3}$$
Answer :
$${O_2}$$
\[2Na+{{O}_{2}}\xrightarrow{{{300}^{\circ }}C}\underset{\left( X \right)}{\mathop{N{{a}_{2}}{{O}_{2}}}}\,\]
$$\mathop {2N{a_2}{O_2}}\limits_{\left( X \right)} + 2C{O_2} \to 2N{a_2}C{O_3} + \mathop {{O_2}}\limits_{\left( Y \right)} $$
154.
The correct order of the solubility of sulphates of alkaline earth metals in water is
A
$$Be> Ca > Mg > Ba > Sr$$
B
$$Mg > Be > Ba > Ca > Sr$$
C
$$Be> Mg > Ca > Sr > Ba$$
D
$$Mg> Ca > Ba > Be > Sr$$
Answer :
$$Be> Mg > Ca > Sr > Ba$$
Solubility of sulphates of alkaline earth metals decreases down the group.
155.
Which of the following does not illustrate the anomalous properties of lithium ?
A
The melting point and boiling point of $$Li$$ are comparatively high
B
$$Li$$ is much softer than the other group $$I$$ metals
C
$$Li$$ forms a nitride $$L{i_3}N$$ unlike group $$I$$ metals
D
The ion of $$Li$$ and its compounds are more heavily hydrated than those of the rest of the
group
Answer :
$$Li$$ is much softer than the other group $$I$$ metals
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 $$S.$$
A
$$N{a_2}C{O_3}$$
B
$$NaOH$$
C
$$NaHC{O_3}$$
D
$$N{H_3}$$
Answer :
$$NaHC{O_3}$$
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.
Column I
Column II
a.
Quick lime
1.
Setting fractured bones
b.
Plaster of Paris
2.
A constituent of chewing gum
c.
Slaked lime
3.
Manufacture of bleaching powder
d.
Limestone
4.
Manufacture of dyestuffs
A
a - 1, b - 4, c - 2, d - 3
B
a - 4, b - 1, c - 3, d - 2
C
a - 2, b - 3, c - 1, d - 4
D
a - 3, b - 2, c - 4, d - 1
Answer :
a - 4, b - 1, c - 3, d - 2
No explanation is given for this question. Let's discuss the answer together.