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

The reagent which does not react with both, acetone and benzaldehyde.

Which is the most suitable reagent for the following conversion?

\[\begin{array}{cc}
\phantom{....................}\ce{O}\phantom{.....................................}\ce{O}\phantom{.}\\
\phantom{....................}||\phantom{......................................}||\phantom{.}\\
\phantom{}\ce{CH3 - CH = CH - CH2 - C - CH3 -> CH3 - CH = CH - CH2 - C - OH}\phantom{.}
\end{array}\]

Through which of the following reactions number of carbon atoms can be increased in the chain?

(i) Grignard reaction

(ii) Cannizaro’s reaction

(iii) Aldol condensation

(iv) HVZ reaction

Match the reactions given in Column I with the suitable reagents given in Column II.

Assertion: Aldehydes and ketones, both react with Tollen’s reagent to form silver mirror.

Reason: Both, aldehydes and ketones contain a carbonyl group.

Arenium ion involved in the bromination of aniline is:

(i)

(ii)

(iii)

(iv)

Why is benzene diazonium chloride not stored and is used immediately after its preparation?

Why does acetylation of –NH₂ group of aniline reduce its activating effect?

Predict the product of reaction of aniline with bromine in non-polar solvent such as \[\ce{CS2}\].

Why is aniline soluble in aqueous HCl?

How will you carry out the following conversions?

toluene `->` p-toluidine

How will you carry out the following conversions?

p-toluidine diazonium chloride `→` p-toluic acid

Match the compounds given in Column I with the items given in Column II.

A colourless substance ‘A’ \[\ce{(C6H7N)}\] is sparingly soluble in water and gives a water soluble compound ‘B’ on treating with mineral acid. On reacting with \[\ce{CHCl3}\] and alcoholic potash ‘A’ produces an obnoxious smell due to the formation of compound ‘C’. Reaction of ‘A’ with benzenesulphonyl chloride gives compound ‘D’ which is soluble in alkali. With \[\ce{NaNO2}\] and \[\ce{HCl}\], ‘A’ forms compound ‘E’ which reacts with phenol in alkaline medium to give an orange dye ‘F’. Identify compounds ‘A’ to ‘F’.

Predict the reagent or the product in the following reaction sequence.

Proteins are found to have two different types of secondary structures viz. α-helix and β-pleated sheet structure. α-helix structure of protein is stabilised by:

Dinucleotide is obtained by joining two nucleotides together by phosphodiester linkage. Between which carbon atoms of pentose sugars of nucleotides are these linkages present?

Optical rotations of some compounds along with their structures are given below which of them have D configuration.

(I)
(II)
(III)

Proteins can be classified into two types on the basis of their molecular shape i.e., fibrous proteins and globular proteins. Examples of globular proteins are:

(i) Insulin

(ii) Keratin

(iii) Albumin

(iv) Myosin

In fibrous proteins, polypeptide chains are held together by:

(i) van der Waals forces

(ii) disulphide linkage

(iii) electrostatic forces of attraction

(iv) hydrogen bonds