Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

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 ______.

The magnetic moment of [NiCl₄]²⁻ is ______.

[Atomic number: Ni = 28]

[Ni(CO)₄] has tetrahedral geometry while [Ni(CN)₄]²⁻ has square planar, yet both exhibit diamagnetism. Explain.
[Atomic number: Ni = 28]

An organic compound 'A' with molecular formula C₅H₈O₂ is reduced to n-pentane with hydrazine followed by heating with NaOH and glycol. 'A' forms a dioxime with hydroxylamine and gives a positive iodoform and Tollen's test. Identify 'A' and give its reaction for iodoform and Tollen's test.

An organic compound 'A' with the molecular formula C₄H₈O₂ undergoes acid hydrolysis to form two compounds 'B' and 'C'. Oxidation of 'C' with acidified potassium permanganate also produces 'B'. Sodium salt of 'B' on heating with soda lime gives methane.

1. Identify 'A', 'B' and 'C'.
2. Out of 'B' and 'C', which will have higher boiling point? Give reason.

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

You are given four organic compounds “A”, “B” , “C” and “D”. The compounds “A”, “B” and “C” form an orange-red precipitate with 2, 4 DNP reagent. Compounds “A” and “B” reduce Tollen’s reagent while compounds “C” and “D” do not. Both “B” and “C” give a yellow precipitate when heated with iodine in the presence of NaOH. Compound “D” gives brisk effervescence with sodium bicarbonate solution. Identify “A”, “B”, “C” and “D” given the number of carbon atoms in three of these carbon compounds is three while one has two carbon atoms. Give an explanation for our answer.

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:

Explain the following term with suitable example.

Cationic detergents

Define the following:

Cationic detergents

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

Explain the following term with suitable examples.

cationic detergents

Explain the following term with suitable examples.

cationic detergents

Explain the following terms with suitable examples Cationic detergents

Explain the following term with a suitable example.

cationic detergents

Give IUPAC names of the following compounds:

 \[\begin{array}{cc}
\ce{CH3 - CH - CH - CH - CH2-OH }\\
|\phantom{......}|\phantom{......}|\phantom{.......}\\
\ce{Cl}\phantom{....}\ce{CH3}\phantom{...}\ce{CH3}\phantom{.....}
\end{array}\]

Explain the following term with suitable examples.

Cationic detergents