How are xenon fluorides XeF2, XeF4 and XeF6 obtained?
XeF2 , XeF4 and XeF6 are obtained by direct reaction between Xe and F2 as follows:

Explain why inspite of nearly the same electronegativity, nitrogen forms hydrogen bonding while chlorine does not.
Name three oxoacids of nitrogen. Write the disproportionation reaction of that oxoacid of nitrogen in which nitrogen is in +3 oxidation state.
In the preparation of H2S06 by contact process, why is S03 not absorbed directly in water to form H2S04?
Write a balanced chemical equation, for the reaction showing catalytic oxidation of NH3 by atmospheric oxygen.
Phosphorus forms a number of oxoacids. Out of these oxoacids phosphinic acid has strong reducing property. Write its structure and also write a reaction showing its reducing behaviour.
What happens when white phosphorus is heated with concentrated NaOH solution in an inert atmosphere of CO2?
How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.
Which of the following statements are correct?
(a) S – S bond is present in H2S2O6.
(b) In peroxosulphuric acid (H2SO5) sulphur is in +6 oxidation state.
(c) Iron powder along with Al2O3 and K2O is used as a catalyst in the preparation of NH3 by Haber's process
(d) Change in enthalpy is positive for the preparation of SO3 by catalytic oxidation of SO2.
Why is nitric oxide paramagnetic in gaseous state but the solid obtained on cooling is diamagnetic?
Explain why does the stability of oxoacids of chlorine increase in the order given below:
HClO < HClO2 < HClO3 < HClO4
Nitric acid forms an oxide of nitrogen on reaction with P4O10. Write the reaction involved. Also write the resonating structures of the oxide of nitrogen formed.
PCl5 reacts with finely divided silver on heating and a white silver salt is obtained, which dissolves on adding excess aqueous NH3 solution. Write the reactions involved to explain what happens.
Match the compounds given in Column I with the hybridization and shape given in Column II and mark the correct option.

Assertion (A): HNO3 makes from passive.
Reason (R): HNO3 forms a protective layer of ferric nitrate on the surface of iron.
Assertion (A): HI cannot be prepared by the reaction of KI with concentrated H2SO4.
Reason (R): HI has lowest H – X bond strength among halogen acids.
Assertion (A): Both rhombic and monoclinic sulphur exist as S8 but oxygen exists as OÏ€.
Reason (R): Oxygen forms pπ-pπ multiple bond due to small size and small bond length but pπ-pπ bonding is not possible in sulphur.
Assertion (A): NaCl reacts with concentrated H2SO4 to give colourless fumes with pungent smell. But on adding MnO2 the fumes become greenish yellow.
Reason (R): MnO2 oxidises HCl to chlorine gas which is greenish yellow.
On heating compound (A) gives a gas (B) which is a constituent of air. This gas when treated with 3 mol of hydrogen (H2 ) in the presence of a catalyst gives another gas (C) which is basic in nature. Gas C on further oxidation in moist condition gives a compound (D) which is a part of acid rain. Identify compounds (A) to (D) and also give necessary equations of all the steps involved. –
Why is BiH3 the strongest reducing agent amongst all the hydrides of group 15 elements? (C.B.S.E. 2013)
Discuss the general characteristics of Group 15 elements with reference to their electronic configuration, oxidation state, atomic size, ionisation enthalpy and electronegativity.