Chapter 11

The p-Block Elements

NCERT Solutions Chemistry Chapter 11 The P-Block Elements Class 11 is an important chapter of chemistry which majorly talks about the P-Block elements in the modern periodic table. The chapter covers different concepts in detail and discusses various questions covering all the topics as per CBSE textbook guidelines. Along with questions and answers, the NCERT Solutions also provides a wide range of MCQs, HOTS, and worksheets that develop a robust understanding to ace the second term examination.

The major purpose of P-Block NCERT Solutions class 11 is to provide a detailed view of chapter 11 and understand its different sections including the introduction, The Boron Family, Compounds of Boron, The Carbon Family, and so much more. Also, a proper and deep analysis of class 11 P-Block will help students understand important trends in modern chemistry. If you’re someone aiming to score higher grades in class 11 and preparing for entrance examinations like JEE Mains, Advance, NEET, and others, Chapter 11 The P-Block Elements class 11 can be a great help.

Topics Covered in this Chapter: (Content Table)

Sr. No. Chapter Name 
1 The P-Block Elements (Introduction) 
2 Group 13 Elements: The Boron Family 
3 Important Trends and Anomalous Properties of Boron 
4 Some Important Compounds of Boron 
5 Uses of Boron and Aluminium and their Compounds 
6 Group 14 Elements: The Carbon Family 
7 Important Trends and Anomalous Behaviour of Carbon 
8 Allotropes of Carbon
9 Some Important Compounds of Carbon and Silicon

The P-Block Elements (Introduction)

Chemistry Class 11 P Block Elements majorly talks about the P-Block elements. In P-Block elements, the last electron enters the outermost p-subshell. The P-Block starts from the 13th group and goes to the 18th group with 35 p-block elements. These elements are great conductors of heat and electricity and tend to lose electrons at regular intervals.

P-Block has some diverse elements, such as Gallium which can melt on the palm. On the other hand, P-Block has elements like Silicon, which is majorly used in making glasses. P-Block elements are from various families, including- 

  • The boron family 
  • Nitrogen family 
  • Oxygen family 
  • Fluorine family 
  • Neon family

The first group in the P-Block is the group of 13 elements. All elements in group 13 of the periodic table are known as the boron family. The members of group 13 elements are-

  • Boron 
  • Gallium 
  • Aluminium 
  • Thallium 
  • Indium

The electronic configuration of the boron family in the periodic table is ns2 np1.

Important Trends and Anomalous Properties of Boron

The group 13 in the modern periodic table is often termed the boron family, which comprises a wide range of physical and chemical properties while following a particular trend.

Trends in properties of boron family members-

  • They react with halogens to give rise to bromides, tri-chlorides, and iodides. 
  • Some of the major compounds like tetrahedral [M(OH)4]– and present in an aqueous medium. 
  • As we move further from boron to thallium, the metallic character keeps on increasing. 

Anomalous Properties of Boron-

  • Since d orbitals are not present, The maximum covalency of boron is only 4. 
  • Out of all elements, boron is the only metalloid. 
  • They are acidic in nature.

Some Important Compounds of Boron

Some Important Compounds of Boron are as follows-

  • Borax

One of the most important compounds of Boron is Borax with the chemical formula of Na2B4 O7.10H2O. When borax is dissolved in water, it gives rise to an alkaline solution which is orthoboric acid. Once the borax is heated, its molecules swell up and start to lose water.

  • Orthoboric acid

The formula for orthoboric acid is H3BO3. It feels soapy when it’s touched and dissolves easily in hot water.

  • Diborane

The chemical formula of diborane is B2H6. Diborane is another major compound of boron that is colourless and rigid with a melting point of 180K.

Uses of Boron and Aluminium and their Compounds 

Some of the uses of Boron are- 

  • Since boron is an extremely hard solid, they are used in making bullet-proof vests. 
  • It is majorly used in the nuclear industry for protective shields. 
  • Borax and boric acid are good conductors of heat. Therefore, they are used in making heat-resistant glasses, fibreglass, and glass wool. 

Some of the uses of aluminium are- 

  • Aluminium is widely used in making pipes, roads, plates, and so on. 
  • Since aluminum is a good conductor of heat, it helps in making aluminium utensils. 
  • In the transport industry, aluminum is used for making cylinder heads, body panels, and so on.

The second group of the P-Block periodic table is the group 14, also known as the carbon family. The members of group 14 are- 

  • Carbon (C)
  • Germanium (Ge)
  • Silicon (Si)
  • Lead (Pb)
  • Tin (Sn)
  • Flerovium (Fl)

  Group 14 Elements
Period Element Atomic No. Electronic Configuration

2nd

Carbon (C)

6

[He]2s2 2p2

3rd

Silicon (Si)

14

[Ne]3s2 3p2

4th

Germanium (Ge)

32

[Ar]3d10 4s2 4p2

5th

Tin (Sn)

50

[Kr]4d10 5s2 5p2

6th

Lead (Pb)

82

[Xe]4f14 5d10 6s2 6p2

 

Earth contains only 0.02% of carbon. Some of the important properties of carbon are- 

  • The small size of an atom 
  • high electrification
  • absence of d-orbitals
  • high ionization energy
  • High boiling and melting point

Allotropes of Carbon 

Carbon with atomic number 6 is one of the most prominent elements present in the modern periodic table, showing allotropy that can be amorphous or crystalline. Carbon is one of those special elements with multiple allotropes as it can have variable oxidation states. Some of the allotropes of carbon are- 

  • Diamond 
  • Lonsdaleite
  • Graphene
  • Q-carbon
  • Graphite
  • Linear acetylenic carbon 
  • Amorphous carbon
  • Carbon nanotubes
  • Fullerenes
  • Buckminsterfullerene

Some Important Compounds of Carbon and Silicon

Some important silicon compounds are as follows- 

  • Silica 

Silica or Silicon dioxide(SiO2) is found in crystalline forms like cristobalite and quartz. Note, silica is mostly non-reactive in nature due to its huge structure. However, it gets easily dissolved in HF and NaOH. 

  • Silicones 

Silicones are a group of organosilicon polymers majorly used as electrical insulators and during surgeries. 

  • Silicates 

The chemical formula of silicates is SiO44-. The most common examples of silicates are glass and cement. 

  • Zeolites 

Zeolites are catalysts that can be easily found in petrochemical industries. It is widely used to soften hard water. 

Some important carbon compounds are as follows- 

  • Ethanol (C2H5OH)

Also known as ethanol alcohol, ethanol is majorly found in alcoholic drinks. Apart from drinks, it is majorly used in the medical industry to manufacture medicines such as cough syrup.  

  • Ethanoic Acid (CH3COOH)

Commonly known as acetic acid, ethanoic acid has a melting point of 290 K higher than other elements in the same group. A common example of ethanoic acid is vinegar.

1- What are p-block elements in Class 11? 

Class 11 P-Block elements, the last electron, enter the outermost p-subshell. The P-Block starts from the 13th group and goes to the 18th group with 35 p-block elements. These elements are great conductors of heat and electricity and tend to lose electrons at regular intervals. 

2- Why are they called p-block elements? 

They are called P-Block elements as their electrons are found in P-orbital. 

3- What are the main concepts covered in this chapter?

The class 11 chapter 11 P-Block elements majorly cover P-Block elements in detail and talk about the Group 13 Elements: The Boron Family and Group 14 Elements: The Carbon Family.

 

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