Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Chemistry

Give reasons for the following observation:

Primary amine on treatment with benzenesulphonyl chloride forms a product which is soluble in NaOH however secondary amine gives product which is insoluble in NaOH.

What is the quantity of electricity in Coulombs required to produce 4.8 g of Mg from molten MgCl₂? How much Ca will be produced if the same amount of electricity was passed through molten CaCl₂? (Atomic mass of Mg = 24 u, atomic mass of Ca = 40 u).

A primary amine 'A' C₂H₇N reacts with alkyl halide (C₂H₅l) to give secondary amine 'B'. 'B' reacts with C₆H₅SO₂Cl to give a solid 'C' which is insoluble in alkali. Identify 'A', 'B', 'C' and write all the chemical reaction involved.

Assertion (A): The enthalpy of mixing Δ_mix H is equal to zero for an ideal solution.

Reason (R): For an ideal solution the interaction between solute and solvent molecules is stronger than the interactions between solute-solute or solvent-solvent molecules.

Assertion: Chlorobenzene is resistant to nucleophilic substitution reaction at room temperature.

Reason (R): C–Cl bond gets weaker due, to resonance.

1 mole of liquid A and 2 moles of liquid B make a solution having a total vapour pressure of 40 torr. The vapour pressure of pure A and pure B are 45 torr and 30 torr, respectively. The above solution ______.

Explain [Fe(CN)₆]³⁻ is an inner orbital complex, whereas [FeF₆]³⁻ is an outer orbital complex.

[Atomic number: Fe = 26]

Why haloarenes are not reactive towards nucleophilic substitution reaction? Give two reactions.

What type of deviation from Roult’s Law is expected when phenol and aniline are mixed with each other? What change in the net volume of the mixture is expected? Graphically represent the deviation.

Assertion (A): During electrolysis of aqueous copper sulphate solution using copper electrodes hydrogen gas is released at the cathode.

Reason (R): The electrode potential of Cu²⁺/Cu is greater than that of H⁺/H₂.

Select the most appropriate answer from the options given below:

What is the basicity of \[\ce{H3PO4}\]?

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

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

NaClO₄ and water

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

Methanol and acetone

How much electricity in terms of Faraday is required to produce 40.0 g of Al from molten Al₂O₃?

(Given: Molar mass of Aluminium is 27 g mol⁻¹.)

Silver crystallises in FCC structure. If density of silver is 10.51 gcm^-3, calculate the volume of unit cell. [Atomic mass of slive (Ag) = 108 gm^-1]

Name the method used for the refining of Nickel metal.

Give reasons for the following:

Aniline does not undergo Friedel- Crafts reaction.

Complete the following equations: