Exercise 1 Question 1
Why are pentahalides more covalent than trihalides?

Exercise 1 Question 2
Why is BiH3 the strongest reducing agent amongst all the hydrides of Group 15 elements?

Exercise 1 Question 3
Why is N2 less reactive at room temperature?

Exercise 1 Question 5
How does ammonia react with a solution of Cu²⁺?

Exercise 1 Question 6
What is the covalence of nitrogen in N₂O₅?

Exercise 1 Question 7
Bond angle in PH⁺₄ is higher than that in PH₃. Why?

Exercise 1 Question 8
What happens when white phosphorus is heated with concentrated NaO Hsolution in an inert atmosphere of CO₂?

Exercise 1 Question 9
What happens when PCl₅ is heated?

Exercise 1 Question 11
What is the basicity of H₃PO₄?

Exercise 1 Question 12

What happens when H₃PO₃ is heated?

Exercise 1 Question 15
Why is H₂O a liquid and H₂S a gas?

Exercise 1 Question 16
Which of the following does not react with oxygen directly?
Zn, Ti, Pt, Fe

Question 17 

Complete the following reactions:  (i) C2H4 + O2 →  (ii) 4Al + 3O2 →

Exercise 1 Question 18
Why does O₃ act as a powerful oxidising agent?

Exercise 1 Question 19
How is O₃ estimated quantitatively?

Exercise 1 Question 20
What happens when sulphur dioxide is passed through an aqueous solution of Fe(III) salt?

Exercise 1 Question 21
Comment on the nature of two S-O bonds formed in SO₂ molecule. Are the two S-O bonds in this molecule equal?

Exercise 1 Question 22
How is the presence of SO₂ detected?

Exercise 1 Question 25
Why is  K_a2 <<  K_a1   for H₂SO₄ in water?

Exercise 1 Question 31
Why is ICl more reactive than I₂?

Exercise 1 Question 32
Why is helium used in diving apparatus?

Exercise 1 Question 33
Balance the following equation:    XeF₆   +   H₂O   →    XeO₂F₂   +   HF

Exercise 1 Question 34 

Why has it been difficult to study the chemistry of radon?

Exercise 2 Question 2
Why does the reactivity of nitrogen differ from phosphorus?

Exercise 2 Question 4
Why does NH₃ form hydrogen bond but PH₃ does not?

Exercise 2 Question 5
How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions involved.

Exercise 2 Question 6
How is ammonia manufactured industrially?

Exercise 2 Question 10
Why does R₃P=O exist but R₃N=O does not (R = alkyl group)?

Exercise 2 Question 12
Nitrogen exists as diatomic molecule and phosphorus as P₄. Why?

Exercise 2 Question 14
Why does nitrogen show catenation properties less than phosphorus?

Exercise 2 Question 16
Can PCl₅ act as an oxidising as well as a reducing agent? Justify.

Exercise 2 Question 18
Why is dioxygen a gas but sulphur a solid?

Exercise 2 Question 19
Knowing the electron gain enthalpy values for O → O^- and O → O^2- as -141 and 702 kJ mol^-1 respectively, how can you account for the formation of a large number of oxides having O^2- species and not O^-? (Hint: Consider lattice energy factor in the formation of compounds).

Exercise 2 Question 20 

Which aerosols deplete ozone?

Exercise 2 Question 21
Describe the manufacture of H₂SO₄ by contact process?

Exercise 2 Question 22
How is SO₂ an air pollutant?

Exercise 2 Question 23
Why are halogens strong oxidising agents?

Exercise 2 Question 27
Why are halogens coloured?

Exercise 2 Question 29
How can you prepare Cl₂ from HCl and HCl from Cl₂? Write reactions only.

Question 30
What inspired N. Bartlett for carrying out reaction between Xe and PtF₆?

Exercise 2 Question 31
What are the oxidation states of phosphorus in the following:
(i) H₃PO₃
(ii) PCl₃
(iii) Ca₃P₂
(iv) Na₃PO₄
(v) POF₃?

Question 32
Write balanced equations for the following:
(i) NaCl is heated with sulphuric acid in the presence of MnO₂.
 (ii) Chlorine gas is passed into a solution of NaI in water.

Exercise 2 Question 33
How are xenon fluorides XeF₂, XeF₄ and XeF₆ obtained?

Question 34
With what neutral molecule is ClO^- isoelectronic? Is that molecule a Lewis base?

Exercise 2 Question 35
How are XeO₃ and XeOF₄ prepared?

Exercise 2 Question 36
Arrange the following in the order of property indicated for each set:
 
(i) F₂, Cl₂, Br₂, I₂- increasing bond dissociation enthalpy.
 
(ii) HF, HCl, HBr, HI - increasing acid strength.
 
(iii) NH₃, PH₃, AsH₃, SbH₃, BiH₃- increasing base strength.

Question 37
Which one of the following does not exist?
(i) XeOF₄
(ii) NeF₂
(iii) XeF₂
(iv) XeF₆

Exercise 2 Question 38
Give the formula and describe the structure of a noble gas species which is isostructural with:
(i) ICl^-₄
(ii) IBr^-₂
(iii) BrO^-₃

Exercise 2 Question 39
Why do noble gases have comparatively large atomic sizes?