Arrange the following oxyacids of chlorine in decreasing order of their thermal stability. Give reason. HOClO 3 , HOCl , HClO 4 , HOClO 2

With the decrease in oxidation state of chlorine, the oxidising power of its oxoacids increases and the thermal stability of oxoacids of chlorine decreases. Thus, the decreasing order of thermal stability is: HClO 4 > HOClO 3 > HOCl 2 > HOClO

How is oxygen prepared from the following compound? PbO 2

Oxygen is prepared by the thermal decomposition of the PbO 2 by the following reaction, PbO 2 s → ∆ 2 PbO s + O 2 g In the above reaction, lead II oxide is also formed as a product.

Explain interhalogen compounds. How is oxygen prepared from the following compound? KClO 4

Interhalogen compounds form when two different halogens react with each other. They can be assigned general compositions as XX ' , XX 3 ' , X X 5 ' ′ and X X 7 ' . Where X = halogen of larger size X ' = halogen of smaller size X is more electropositive than X ' and as the ratio between radii of X and X ' increases, the number of atoms per molecule also increases. Oxygen can be prepared in laboratory by the heating of of KClO 3 by the following reaction, KClO 4 s → MnO 2 ∆ KCl s + 2 O 2 g In the above reaction, potassium chloride is also formed as a product.

Draw the structure of sulphurous acid. Explain why nitrogen does not form pentahalides.

Sulphurous acid is a chemical compound THAT has a chemical formula H 2 SO 3 . It is formed when sulphur dioxide is dissolved in water. It has the following structure, Nitrogen does not form pentahalide due to non-availability of the d orbitals in its valence shell. Valence shell electronic configuration of nitrogen is 2 s 2 2 p 3 . Therefore, it can accommodate maximum of three electrons in its valence p -orbital. As nitrogen does not have d -orbital, so it cannot increase its coordination number. So it cannot form pentahalides.

Explain the following with the help of balanced chemical equation: Dehydration of formic acid by concentrated H 2 SO 4

Concentrated H 2 SO 4 is a strong dehydrating agent due to its affinity for water. Reaction: HCOOH → Conc . H 2 SO 4 CO + H 2 O

Explain the following with the help of balanced chemical equation: Bleaching action of SO 2

SO 2 is used as a bleaching agent in presence of moisture. Bleaching takes place due to reduction and it is temporary. Reaction: SO 2 + 2 H 2 O → H 2 SO 4 + 2 ( H )

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2018>Q 4

EASY

12th Maharashtra Board

IMPORTANT

Earn 100

Write structure and molecular formula for the following compounds:
orthophosphoric acid

Important Questions on p-block Elements

EASY

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2018>Q 5

Write structure and molecular formula for the following compounds:
sulphurous acid

EASY

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2018>Q 6

Write any ‘four points’ of difference between fluorine and other halogens.

EASY

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2018>Q 7

Which of the following compounds of chlorine is used as refrigerant?

HARD

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2019>Q 8

Write chemical reactions for different steps in the manufacture of sulphuric acid by lead chamber process. Draw the structure of phosphorus pentachloride.

EASY

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2019>Q 9

Explain the following property of group 16 elements:

Electronegativity

EASY

12th Maharashtra Board

IMPORTANT

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter 7 - p-block Elements>Maharashtra Board-2019>Q 10

Explain the following property of group 16 elements:

Melting and boiling points