PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions for Chemistry

[Fe(H₂O)₆]³⁺ is strongly paramagnetic whereas [Fe(CN)₆]³⁻ is weakly paramagnetic. Explain.

Explain [Co(NH₃)₆]³⁺ is an inner orbital complex, whereas [Ni(NH₃)₆]²⁺ is an outer orbital complex.

[At. No.: Co = 27, Ni = 28]

Amongst the following ions, which one has the highest magnetic moment value?

How the following conversion can be carried out?

Chlorobenzene to p-nitrophenol

List the important sources of sulphur.

Write the order of thermal stability of the hydrides of Group 16 elements.

Why is H₂O a liquid and H₂S a gas?

Which of the following does not react with oxygen directly?

Zn, Ti, Pt, Fe

Why does NH₃ form hydrogen bond but PH₃ does not?

The HNH angle value is higher than HPH, HAsH and HSbH angles. Why? [Hint: Can be explained on the basis of sp³ hybridisation in NH₃ and only s−p bonding between hydrogen and other elements of the group].

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.

Knowing the electron gain enthalpy values for \[\ce{O -> O-}\] and \[\ce{O -> O^{2-}}\] as −141 and 702 kJ mol⁻¹ respectively, how can you account for the formation of a large number of oxides having O²⁻ species and not O⁻?

(Hint: Consider lattice energy factor in the formation of compounds).

Why are halogens strong oxidising agents?

Explain why inspite of nearly the same electronegativity, oxygen forms hydrogen bonding while chlorine does not.

Give reasons:

The dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.

Arrange the following in the order of property indicated for the given set:

F₂, Cl₂, Br₂, I₂ - increasing bond dissociation enthalpy.

State second law of electrolysis

Suggest the most important type of intermolecular attractive interaction in the following pair.

n-hexane and n-octane

Suggest the most important type of intermolecular attractive interaction in the following pair:

I₂ and CCl₄