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

Match the items of column I with items of column II.

Match the items of column I with items of column II.

Assertion: Ethanol is a weaker acid than phenol.

Reason: Sodium ethoxide may be prepared by the reaction of ethanol with aqueous \[\ce{NaOH}\].

The correct order of increasing acidic strength is ______.

In the nitration of benzene using a mixture of conc. \[\ce{H2SO4}\] and conc. \[\ce{HNO3}\], the species which initiates the reaction is ______.

What is the role of \[\ce{HNO3}\] in the nitrating mixture used for nitration of benzene?

A solution contains 1 g mol. each of p-toluene diazonium chloride and p-nitrophenyl diazonium chloride. To this 1 g mol. of alkaline solution of phenol is added. Predict the major product. Explain your answer.

Assertion: N, N-Diethylbenzene sulphonamide is insoluble in alkali.

Reason: Sulphonyl group attached to nitrogen atom is strong electron-withdrawing group.

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 polymer is biodegradable?

Which of the following polymer can be formed by using the following monomer unit?

Which of the following monomers form biodegradable polymers?

(i) 3-hydroxybutanoic acid + 3-hydroxypentanoic acid

(ii) Glycine + amino caproic acid

(iii) Ethylene glycol + phthalic acid

(iv) Caprolactum

Convert the following: 

Propanenitrile to ethanol.

[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.