Class 12 Chemistry NCERT Exemplar Solutions: Chapter 7, The p-Block Elements

In this article, we are providing the NCERT Exemplar Solutions for all the questions of CBSE 12 Chemistry chapter 7, The p-Block Elements.

About the NCERT Exemplar Problems and Solutions for Class 12 Chemistry:

Every year in the CBSE Board Exams, the class 12 Chemistry question paper includes a few problems (generally HOTS type) are asked from NCERT Exemplar book. Questions are either asked directly or in a twisted manner. Therefore, owing to the importance of NCERT Exemplar problems, we at jagranjosh have collated appropriate answers to all these problems.

NCERT Exemplar solutions for chapter - The p-Block Elements, are explained by the subject matter experts. All the solutions are designed in a way to help students easily understand various concepts and theories involved. NCERT exemplar solutions given here are a perfect preparation tool to do well in your boards as well as other entrance exams.

NCERT Exemplar solutions are available in the form of PDF which students can download for free of cost and refer the same when required.

Few problems along with their solutions from this chapter are given below:

Q. Maximum covalency of nitrogen is _______.

(a) 3       (b) 5       (c) 4       (d) 6

Ans. (c) 4

Maximum covalency of nitrogen is 4 in which one electron is made available by s-orbital and 3 electrons are made available by p-orbitals. Hence, total four electrons are available for bonding.

Q. Which of the following options are not in accordance with the property mentioned against them?

(a) F₂ > Cl₂ > Br₂ > I₂      Oxidising power

(b) MI > MBr > MCl > MF   Ionic character of metal halide

(c) F2 > Cl₂ > Br₂ > I₂      Bond dissociation enthalpy

(d) HI < HBr < HCl < HF    Hydrogen-halogen bond strength

Answer. (b, c)

(b) As ability to gain electron increases oxidising property increases. Here, F is the most electronegative element having highest value of SRP hence it has highest oxidising power.

Correct order of ionic character of metal halide is:

                                                                     MI < MBr < MCl < MF

As electronegativity difference between metal and halogen increases, ionic character increases.

(c) Due to electronic repulsion among lone pair in F₂ molecule, the correct order of bond dissociation enthalpy is as follows:

                                                                      Cl₂ > Br₂ > F₂>I₂

CBSE Class 12 Chemistry Syllabus 2018 – 2019

Q. PH₃ forms bubbles when passed slowly in water but NH₃ dissolves. Explain why?

Ans. Dissolution of NH₃ and PH₃ in water can be explained on the basis of H-bonding. NH₃ forms H-bond with water so, it is soluble but PH₃ does not form H-bond with water so it remains as gas and forms bubble in water.

Q. Assertion (A) HNO₃ makes iron passive.

Reason (R) HNO₃ forms a protective layer of ferric nitrate on the surface of iron.

Ans. (c) Assertion is true, but reason is false.

HNO₃ makes iron passive due to formation of passive form of oxide on the surface. Hence, Fe does not dissolve in conc. HNO₃ solution.

Find below the links to download Class 12 Chemistry NCERT Exemplar Solutions for chapter 6- The p-Block Elements:

Class 12 Chemistry NCERT Solutions: All Chapters

Class 12 Chemistry NCERT Exemplar Problems: The p-Block Elements

To add to the learning skill of students and test their comprehension, information recall, analytical thinking and problem-solving ability, some excellent problems have been developed and collected in the form of ‘Exemplar Problems’. These problems are not meant to serve merely as a question bank for examinations but are primarily meant to improve the quality of learning among students.

All the problems given in NCERT Exemplar book are very important for CBSE Class 12 board examination and other competitive examinations.

Important topics discussed in Class 12 Chemistry chapter – The p-Block Elements, are:

• Group 15 Elements
• Dinitrogen
• Ammonia
• Oxides of Nitrogen
• Nitric Acid
• Phosphorus — Allotropic Forms
• Phosphine
• Phosphorus Halides
• Oxoacids of Phosphorus
• Group 16 Elements
• Dioxygen
• Simple Oxides
• Ozone
• Sulphur — Allotropic Forms
• Sulphur Dioxide
• Oxoacids of Sulphur
• Sulphuric Acid
• Group 17 Elements
• Chlorine
• Hydrogen Chloride
• Oxoacids of Halogens
• Interhalogen Compounds
• Group 18 Elements 

Download the complete NCERT Exemplar problems from the following link:

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