The incorrect statement among the following is- 

1. Sodium metal is used in organic qualitative analysis.

2. Sodium carbonate is soluble in water and it is used in inorganic qualitative analysis.

3. Potassium carbonate can be prepared by the solvay process.

4. Aq. solution of potassium bicarbonate is a weak base.

Lithium shows a diagonal relationship with : 

1. Sodium

2. Magnesium

3. Calcium

4. Aluminium

In case of alkali metal halides, the ionic character increases in the order : 

1. MF < MCl < MBr < MI

2. MI < MBr < MCl < MF

3. MI < MBr < MF < MCl

4. None of the above.

A molecule among the following that has the highest hydration energy is -

1. MgCl₂

2. CaCl₂

3. BaCl₂

4. SrCl₂

The compound (X) on heating gives a colorless gas and a residue that is dissolved
in water to obtain (B). Excess of CO${}_2$ is bubbled through an aqueous solution of B, C is
formed. Solid (C) on heating gives back X. (B) is

1. CaCO${}_3$

2. Ca(OH)${}_2$

3. Na${}_2$CO${}_3$

4. NaHCO${}_3$

Among the following the least thermally stable carbonate is : 

$1.$ ${\mathrm{K}}_2{\mathrm{CO}}_3$

2. ${\mathrm{Na}}_2{\mathrm{CO}}_3$

3. ${\mathrm{BaCO}}_3$

4. ${\mathrm{Li}}_2{\mathrm{CO}}_3$

One mole of calcium phosphide upon reacting with water gives:

1. One mole of the phosphene.

2. Two moles of phosphoric acid.

3. Two moles of phosphine.

4. One mole of phosphorus pentaoxide.

Which of these is not used as fuel in the rocket propellants?

1. Liquid He

2. Liquid hydrogen

3. Kerosene

4. Liquid hydrazine

Fire extinguishers contain $H_{2}S{O}_4$ and __ _

1. ${\mathrm{NaHCO}}_3$ and ${\mathrm{Na}}_2{\mathrm{Co}}_3$

2. ${\mathrm{NaHCO}}_3$ solution

3. ${\mathrm{Na}}_2{\mathrm{Co}}_3$

4. ${\mathrm{CaCO}}_3$

Sodium nitrate decomposes above 800°C and does not give:

1. ${\mathrm{N}}_2$

2. ${\mathrm{O}}_2$

3. ${\mathrm{NO}}_2$

4. Na₂O