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

Preparation of alcohols from alkenes involves the electrophilic attack on alkene carbon atom. Explain its mechanism.

Explain why low molecular mass alcohols are soluble in water.

\[\begin{array}{cc}
\ce{CH3 - C ≡ CH ->[40{%} H2SO4][1{%} HgSO4] A ->[Isomerisation] CH3 - C - CH3}\\
\phantom{........................................}||\\
\phantom{........................................}\ce{O}\\
\end{array}\]

Structure of ‘A’ and type of isomerism in the above reaction are respectively.

Amino acids are classified as acidic, basic or neutral depending upon the relative number of amino and carboxyl groups in their molecule. Which of the following are acidic?

(i)

\[\begin{array}{cc}
\ce{(CH3)2CH - CH - COOH}\\
\phantom{..}|\\
\phantom{.....}\ce{NH2}
\end{array}\]

(ii)

\[\begin{array}{cc}
\ce{HOOC - CH2 - CH2 - CH - COOH}\\
\phantom{............}|\\
\phantom{...............}\ce{NH2}
\end{array}\]

(iii)

\[\ce{H2N - CH2 - CH2 - CH2 - COOH}\]

(iv)

\[\begin{array}{cc}
\ce{HOOC - CH2 - CH - COOH}\\
\phantom{.....}|\\
\phantom{........}\ce{NH2}
\end{array}\]

Assertion: Glycine must be taken through diet.

Reason: It is an essential amino acid.

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.

How would you account for the following:

There is a greater range of oxidation states among the actinoids than among the lanthanides.

Name the suitable alcohol and reagent, from which 2-Chloro-2-methyl propane can be prepared.

Write the equations for the following reaction:

Tert butyl chloride is treated with sodium ethoxide.

Why does the cell voltage of a mercury cell remain constant during its lifetime?

Write any two consequences of Lanthanoid Contraction.

Which of the following reactions are feasible?

Give reasons:

Mercury cell delivers a constant potential during its life time.

Write the mechanism of the following reaction:

\[\ce{2CH3CH2OH ->[H^+][413 K] CH3-CH2-O-CH2-CH3 + H2O}\]

Draw the zwitter ion structure for sulphanilic acid.

Give a reason for the following observations:

Amino acids behave like salts.

A non-volatile solute 'X' (molar mass = 50 g mol₋₁), when dissolved in 78 g of benzene, reduced its vapour pressure to 90%. Calculate the Mass of X dissolved in the solution.