P Block Elements

This is a short answer type question as classified in NCERT Exemplar

NO₂ exists as a monomer with one unpaired electron in the gaseous state, but it dimerises to N₂O₄ in the solid state, leaving no unpaired electron, making the solid form diamagnetic.

This is a short answer type question as classified in NCERT Exemplar

Three P—Cl bonds are arranged in one plane at a 1200 angle. These bonds are known as equatorial bonds because they are formed between two points. The remaining two P—Cl bonds, one above the equatorial plane and the other below it, form  90° angle with the plane. Axial bonds are the name for these types of bonds. Because axial bond pairs are subjected to greater repulsive interaction than equatorial bond pairs, axial bonds are slightly longer and hence slightly weaker than equatorial bonds, making the PCl₅ molecule more reactive.

This is a short answer type question as classified in NCERT Exemplar

PH₃ is insoluble in water and cannot create hydrogen bonds with it, it forms bubbles, whereas NH₃ dissolves because it is soluble in water and can form hydrogen bonds with it.

This is a short answer type question as classified in NCERT Exemplar

This is a short answer type question as classified in NCERT Exemplar

4NH₃ + 5O₂ 4NO + 6H₂O

This is a short answer type question as classified in NCERT Exemplar

SO₃ generates a dense fog of sulphuric acid that does not condense quickly, it is not absorbed directly in water to form H₂SO_4.

This is a long answer type question as classified in NCERT Exemplar

A = NH₄NO₂

B = N₂

C = NH₃

D = HNO₃ 

(i) NH₄NO₂→N₂ + 2H₂O

(ii) N₂ + 3H₂→2NH₃

(iii) 4NH₃ + 5O₂→4NO + 6H₂O

4NO + O₂→4NO₂

3NO₂ + H₂O→2HNO₃ + NO 

This is a long answer type question as classified in NCERT Exemplar

Here, 'A' is NO₂ (Nitrogen dioxide)

'B' is N₂O₄ (dinitrogen tetraoxide)

'C' is N₂O₃ (dinitrogen trioxide)

A brown gas is produced when lead nitrate (II) is heated

2Pb (NO₃)₂ 2PbO  +  4NO₂ + O₂

2NO₂ N₂O₄

2NO  + N₂O₄ 2N₂O₃ 

This is a long answer type question as classified in NCERT Exemplar

'A' is S₈ 'B' is SO₂ gas

 S₈ + 8O₂ 8SO₂

2MnO₄ ^– + 5SO₂ + 2H₂O → 5 SO₄^2– + 4H⁺ + 2Mn²⁺

(violet)                                                              (colourless)

2Fe³⁺ + SO₂ + 2H₂O → 2Fe²⁺ + SO₄^2– + 4H⁺