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

Match the complex ions given in Column I with the hybridisation and number of unpaired electrons given in Column II and assign the correct code:

Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following:

\[\ce{[CoF6]^{3-}, [Co(H2O)6]^{2+}, [Co(Cn)6]^{3-}}\]

Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following:

\[\ce{[FeF6]^{3-}, [Fe(H2O)6]^{2+}, [Fe(CN)6]^{4-}}\]

Why are different colours observed in octahedral and tetrahedral complexes for the same metal and same ligands?

Match the reactions given in Column I with the names given in Column II.

	Column I	Column II
(i)		(a) Fittig reaction
(ii)		(b) Wurtz Fittig reaction
(iii)		(c) Finkelstein reaction
(iv)	\[\ce{C2H5Cl + Nal ->[dry acetone] C2H5l + NaCl}\]	(d) Sandmeyer reaction

Assertion: tert-Butyl bromide undergoes Wurtz reaction to give 2, 2, 3, 3-tetramethylbutane.

Reason: In Wurtz reaction, alkyl halides react with sodium in dry ether to give hydrocarbon containing double the number of carbon atoms present in the halide.

Which of the following acids is a vitamin?

Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is said to be ______.

Lysine, \[\begin{array}{cc}
\ce{H2N - (CH2)4 - CH - COOH}\\
\phantom{.....}|\\
\phantom{........}\ce{NH2}
\end{array}\] is:

(i) α-Amino acid

(ii) Basic amino acid

(iii) Amino acid synthesised in body

(iv) β-Amino acid

Amino acids can be classified as α–, β–, γ–, δ– and so on depending upon the relative position of amino group with respect to carboxyl group. Which type of amino acids form polypetide chain in proteins?

Amino acids behave like salts rather than simple amines or carboxylic acids. Explain.

Describe the term D- and L- configuration used for amino acids with examples.

Which of the following polymers have vinylic monomer units?

(i) Acrilan

(ii) Polystyrene

(iii) Nylon

(iv) Teflon

How is the following resin intermediate prepared and which polymer is formed by this monomer unit?

 (Resin intermediate)

Match the polymers given in Column I with their commercial names given in Column II.

Which of the following polymers soften on heating and harden on cooling? What are the polymers with this property collectively called? What are the structural similarities between such polymers? Bakelite, urea-formaldehyde resin, polythene, polyvinyls, polystyrene.

[Ni(H₂O)₆]²⁺ (aq) is green in colour whereas [Ni(H₂O)₄ (en)]²⁺ (aq)is blue in colour, give reason in support of your answer.

In a coordination entity, the electronic configuration of the central metal ion is t_2g³ e_g¹ 

Draw the crystal field splitting diagram for the above complex.

The CFSE of [CoCl₆]^3– is 18000 cm^–1 the CFSE for [CoCl₄]^– will be ______.

Given below are two statements labelled as Assertion (A) and Reason (R).

Assertion (A): An ether is more volatile than an alcohol of comparable molecular mass

Reason (R): Ethers are polar in nature.

Select the most appropriate answer from the options given below: