CBSE Class 12-science Answered

P-Block

Here are some important topics/questions:

Trends in chemical reactivity of group 15 elements.
Dinitrogen - preparation
Allotropes of phosphorus- structure, preparation, manufacture.
Allotropes of sulphur-structure, preparation, manufacture.
Anomalous behaviour of fluorine.
Manufacture of chlorine.
How are xenon fluorides obtained?
Calculate the oxidation states of phosphorous in the given compound.
Oxoacids of halogens-reactions and properties.
Describe the manufacture H₂SO₄ by contact process?
Why are halogens strong oxidising agents?
How ammonia is manufactured industrially?

Interhalogen compounds 

Basicity of group 15 element

Most important topics/questions

1. Structures of PCl₅, H2SO₃, H₂SO₄, H₂S₂O₈, H₂S₂O₇, HOCl, HClO₂, HClO₃, HClO₄
2. Complete the reactions:
3. Conceptual questions:

• NF₃ is an exothermic compound whereas NCl₃ is not.
• NH₃ is a stronger base than PH₃. Why?
• Arrange the following in order of the indicated property:
  • F₂, Cl₂, Br₂, I₂ in increasing order of bond dissociation enthalpy
  • HF, HCl, HBr, HI in increasing order of acidic strength
  • NH₃, PH₃, AsH₃, SbH₃, BiH₃ in increasing order of basic strength
• What are interhalogen compounds?

The important topics/sections/questions from d and f-block elements are:

• Why is Ce (IV) good analytical reagent?
• General trends in the properties of transition and inner transition elements.

• Ionisation energies and ionisation enthalpies.
• Standard electrode potential (E^o) and Chemical reactivity of both d and f block elements
• Complex formation
• Alloy formation
• Salts containing oxoanions of transition metals.

• Why is the absorption bands narrow in f elements?
• What happens at the third ionization enthalpy of f block elements?
• List the irregularities in the actinide series compared to the lanthanide?
• Compare the different characteristic of lanthanides and actinides?
• Actinide contraction is greater from element to element than lanthanide contraction. Why?
• List some practical applications of f block elements?
• The chemistry of the actinide elements is not as smooth as that of the lanthanides. Justify?
• Oxidation states of lanthanoids and actinoids

Hope this helps!!