P Block Elements

(i) Explanation.
Nitrogen has only and orbitals, no vacant d-orbitals. Therefore, nitrogen cannot expand its octet to form NCl . But phosphorus (in PCl ) can, due to vacant 3d orbitals. Hence only NCl exists.
(ii) Explanation.
Halogens have high electronegativity and very high electron affinity. They readily accept electrons to form halide ions, making them strong oxidising agents.

(i) Concentrated H SO is added in calcium fluoride:
When concentrated sulfuric acid is added to calcium fluoride, it reacts to form calcium bisulfate and hydrogen fluoride gas:
(ii) SO is passed in water:
Sulfur trioxide reacts with water to form sulfuric acid:
(iii) Calcium hydroxide reacts with ammonium chloride:
Calcium hydroxide reacts with ammonium chloride to form calcium chloride, water, and ammonia gas:
(iv) Concentrated sulphuric acid and copper metal is heated:
When concentrated sulfuric acid reacts with copper metal, it forms copper(II) sulfate and sulfur dioxide gas:
(v) Chlorine gas is passed in cold caustic soda solution:
When chlorine gas is passed through cold caustic soda (sodium hydroxide), it forms sodium chloride and sodium hypochlorite:

Step 1: Preparation of Dinitrogen.
Dinitrogen is prepared in the laboratory by heating ammonium nitrite ( ) or by passing ammonia gas over heated copper oxide. The chemical equations for these processes are: or
Step 2: Reaction of Dinitrogen with Oxygen.
When dinitrogen reacts with oxygen at high temperatures, it forms nitrogen monoxide (NO):
Step 3: Reaction of Dinitrogen with Magnesium.
At high temperatures, dinitrogen reacts with magnesium to form magnesium nitride (Mg N ):
Step 4: Reaction of Dinitrogen with Hydrogen.
At 773 K, in the presence of a catalyst (such as iron), dinitrogen reacts with hydrogen to form ammonia:

Step 1: Deacon’s process.
In Deacon’s process, chlorine is manufactured by the oxidation of hydrogen chloride gas using oxygen in the presence of a catalyst (CuCl ).
Step 2: Reaction of chlorine with sulphur.
When chlorine reacts with sulphur, sulphur dichloride is formed.
Conclusion:
- Deacon’s process is an industrial method for preparing chlorine.
- Chlorine reacts with sulphur to give sulphur dichloride (SCl ).

Step 1: Manufacture of SO .
SO is produced by burning sulphur or roasting metal sulphides in air/oxygen.
Step 2: Important reactions.
Step 3: Reactions of H SO .
Step 4: Conclusion.
SO is industrially produced by roasting sulphides, and conc. H SO liberates gases from CaF , Cu, and S.

(i) Iodine with HNO .
Nitric acid oxidises iodine to iodic acid: (ii) Chlorine with SO .
Chlorine oxidises SO to H SO : (iii) Chlorine with hot conc. NaOH.
Disproportionation reaction: (iv) Chlorine with fluorine.
Formation of chlorine trifluoride: (v) Zinc with dilute nitric acid.
Zinc gives zinc nitrate and nitrogen dioxide gas: