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

For the complex [Fe(H₂O)₆]+3, write the hybridisation, magnetic character and spin of the complex. (At, number : Fe = 26)

Using the E° values of A and B, predict which is better for coating the surface of iron [E°(Fe⁺²/Fe) = -0.44V] to prevent corrosion and why?

Given: E° (A⁺²/A)=-2.37 V: E°(B⁺²/B)= -0.14V

Following reactions occur at cathode during the electrolysis of aqueous sodium chloride solution:

Na+(aq) + e⁻ ⟶ Na (s) E⁰ =  2.71 V

H+(aq) + e⁻ ⟶ `1/2`  H₂ (g) E⁰ = 0.00 V

On the basis of their standard reduction electrode potential (E⁰) values, which reaction is feasible at the cathode and why?

Reduction of metal oxide to metal becomes easier if the metal obtained is in liquid state. Why?

For the complex [Fe(CN)₆]^3–, write the hybridization type, magnetic character and spin nature of the complex. (At. number : Fe = 26).

Write the hybridization and magnetic behaviour of the complex [Ni(CO)₄].

(At.no. of Ni = 28)

It is necessary to remove CO when ammonia is prepared by Haber's process.

The presence of nitro group (−NO₂) at o/p positions increases the reactivity of haloarenes towards nucleophilic substitution reactions.

Account for the following : There is large difference between the melting and boiling points of oxygen and sulphur.

Give a simple chemical test to distinguish between the following pair of compounds :

(CH₃)₂NH and (CH₃)₃N

Write the dispersed phase and dispersion medium of butter.

Give reasons for the following : H₂Te is the strongest reducing agent amongst all the hydrides of Group 16 elements.

Write the hybridization and shape of the following complexe : [CoF₆]^3–

(Atomic number : Co = 27, Ni = 28)

Write the hybridization and shape of the following complexe : [Ni(CN)₄]^2–

^{(Atomic number : Co = 27, Ni = 28)}

What is the role of zinc metal in the extraction of silver ?

Give reasons for the following : Oxygen has less electron gain enthalpy with negative sign than sulphur.

What role does the molecular interaction play in a solution of alcohol and water?

How is the sign of Δ_mixH related to positive deviations from Raoult’s law?

Heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components are 105.2 kPa and 46.8 kPa respectively. What will be the vapour pressure of a mixture of 26.0 g of heptane and 35 g of octane?

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

Acetonitrile (CH₃CN) and acetone (C₃H₆O)