Why is dioxygen a gas but sulphur a solid?
Due to the small size and high electronegativity, oxygen forms pπ- pπ multiple bonds. As a result, oxygen exists as diatomic (O2) molecules. These molecules are held together by weak van der Waal’s forces of attraction which can be overcome by collisions of the molecules at room temperature. Therefore, O2 is a gas at room temperature. Due to its bigger size and lower electronegativity, sulphur does not form pn-pn multiple bonds. It prefers to form S – S single bonds. S – S single bond is stronger then O-O single bond. Thus, sulphur has higher tendency for catenation than oxygen. Due to higher tendency for catenation and lower tendency for pπ – pπ multiple bonds sulphur exits as octa-atomic (Sg) molecule. Due to bigger size, the force of attraction holding the Sg molecules together are much stronger which cannot be overcome by collisions of molecules at room temperature. Therefore, sulphur is solid at room temperature.
Name three oxoacids of nitrogen. Write the disproportionation reaction of that oxoacid of nitrogen in which nitrogen is in +3 oxidation state.
Explain why inspite of nearly the same electronegativity, nitrogen forms hydrogen bonding while chlorine does not.
Why is BiH3 the strongest reducing agent amongst all the hydrides of group 15 elements? (C.B.S.E. 2013)
Explain why does the stability of oxoacids of chlorine increase in the order given below:
HClO < HClO2 < HClO3 < HClO4
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.
What happens when sulp’hur dioxide is passed through an aqueous solution of Fe(III) salt?
How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.
Why does nitrogen show catenation properties less than phosphorus ? (C.B.S.E. Foreign 2009)
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.
How is nitrogen prepared in the laboratory? Write the chemical equations of the reactions . involved.
Reduction potentials of some ions are given below. Arrange them in decreasing order of oxidizing power.
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?
