Calcium burns in nitrogen to produce a white solid which dissolves in sufficient water to produce a gas $\overline{)A}$ and an alkaline solution. The solution on exposure to air produces a solid layer of $\overline{)B}$ on the suface. The compound $\overline{)A}$ and $\overline{)B}$ are

1 $\overline{)A}$ Ca₃N₂, $\overline{)B}$ CaO

2 $\overline{)A}$ Ca₃N₂, $\overline{)B}$ NH₃

3 $\overline{)A}$ NH₃, $\overline{)B}$ CaCO₃

4 $\overline{)A}$ CaCO₃, $\overline{)B}$ CaO

Which of the following chemical reaction is incorrect?

1 2KNO₃(s)$\stackrel{△}{\to }$ K₂O(s)+2NO₂(g)+ $\frac{1}{2} O_2\left(g\right)$

2 2LiNO₃(s)$\stackrel{△}{\to }$ Li₂O(s)+2NO₂(g)+ $\frac{1}{2} O_2\left(g\right)$

3 2NaHCO₃(s)$\stackrel{△}{\to }$ Na₂CO₃(s)+H₂O(g)+CO₂(g)

4 2KO₂(s)+CO₂(g)$\stackrel{△}{\to }$ K₂CO₃(s)+ $\frac{3}{2}{O}_2\left(g\right)$

The hydration energy of Mg⁺² ions is larger than that of

1 Al⁺³

2 Na⁺

3 Be⁺²

4 Mg⁺³

Which is mismatched?

1. $Plaster of Paris -CaS{O}_4. \frac{1}{2}{H}_{2}O$

2. $Epsom salt - MgS{O}_4.7H_{2}O$

3. $Chile salt petre-KN{O}_3$

4. $Glauber salt - N{a}_{2}S{O}_4.10H_{2}O$

An atom among the following that shows lowest ionic mobility when aqueous solutions of its salts are put under an electric field is -

1. K

2. Rb

3. Li

4. Na

Cement, the important building material is a mixture of oxides of several elements. Besides calcium, iron, and sulphur, oxides of elements of which of the group (s) are present in the mixture?

1.  group 2

2.  groups 2, 13 and 14

3.  groups 2 and 13

4.  groups 2 and 14

Which one of the following alkali metal does not form alums?

1. Li

2. Na

3. K

4. All of the above

Which is mismatched?

1 NaOH-Castner-Kellner cell

2 K₂CO₃-Solvary Ammonia process

3 H₂O₂-Merck's method

4 All of the above

Which will react with N₂ to form nitride?

1 Li

2 Na

3 K

4 Rb