Q. Why does $N{H}_3$ form hydrogen bond but $P{H}_3$ does not?

Q. Discuss the trends in chemical reactivity of group $15$ elements.

Q. Explain why $N{H}_3$ is basic while $Bi{H}_3$ is only feebly basic.

Q. Illustrate how copper metal can give different products on reaction with $HN{O}_3$.

Q. Why does the reactivity of nitrogen differ from phosphorus?

Q. Justify the placement of $O,S,Se,Te$ and $Po$ in the same group of the periodic table in terms of electronic configuration, oxidation state and hydride formation.

Q. How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions involved.

Q. Why is dioxygen a gas but sulphur a solid?

Q. Give the disproportionation reaction of $H_{3}P{O}_3$.

Q. Which aerosols deplete ozone?

Q. Give reasons for the following:
$R_{3}P=O$ exists but $R_{3}N=O$ does not, $R$ is an alkyl group?

Q. Discuss the general characteristics of Group $15$ elements with reference to their electronic configuration, oxidation state, atomic size, ionisation enthalpy and electronegativity

Q. Give the resonating structures of $N{O}_2$ and $N_2{O}_5$

Q. Knowing the electron gain enthalpy values for $O\to O^{-}$ and $O\to O^{2-}$ as $-141$ and $702kJmo{l}^{-1}$ respectively, how can you account for the formation of a large number of oxides having $O^{2-}$ species and not $O^{-}$?

Q. Can $PC{l}_5$ act as an oxidising as well as a reducing agent? Justify.

Q. Write main differences between the properties of white phosphorus and red phosphorus.

Q. Nitrogen exists as diatomic molecule and phosphorus as $P_4$. Why?

Q. How is ammonia manufactured industrially?

Q. Why does nitrogen show catenation properties less than phosphorus?

Q. The $HNH$ angle value is higher than $HPH,HAsH$ and $HSbH$ angles. Why?