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

Give the structures of A, B and C in the following reactions :

Write the IUPAC name of the compound.

Write the principles of the following methods :

Froth floatation method

Write IUPAC name of the complex K3 [Cr (C₂O₄)3] 

Write the IUPAC name of the follow

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

Account for the following:
Gabriel phthalimide synthesis is not preferred for preparing aromatic primary amines.

 Write structures of compounds A and B in each of the following reactions:

Arrange the following polymers in increasing order of their intermolecular forces: 
Polyvinylchloride, Neoprene, Terylene

Differentiable between the following: 
Amylose and Amylopectin 

Account for the following : 
Manganese shows maximum number of oxidation states in 3d series. 

E⁰ value for  Mn³⁺ Mn²⁺ couple is much more positive than that for Cr^3-/ Cr^2-.

 Write the chemical equation for the preparation of 4 KMnO from 2. MnO Why does purple colour of acidified permanganate solution decolourise when it oxidises Fe^2- to Fe³⁺ ? 

 Write the ionic equation showing the oxidation of Fe(II) salt by acidified dichromate solutions. 

Answer the following question.
What is the basic structural difference between glucose and fructose?

Answer the following question.
When MnO₂ is fused with KOH in the presence of KNO₃ as an oxidizing agent, it gives a dark green compound (A). Compound (A) disproportionates in an acidic solution to give a purple compound (B).  An alkaline solution of compound (B) oxidizes KI to compound (C) whereas an acidified solution of compound (B) oxidizes KI to (D). Identify (A), (B), (C), and (D).

Using IUPAC norms, write the formula of potassium trioxalatochromate(III).

Write the structure of main compounds A and B in the following reaction:

\[\ce{CH3CH2CN->[CH3MgBRH/3O+]A->[LiAIH4]B}\]

Write the reaction involved when D-glucose is treated with the following reagent:

Br₂ water

Write the reactions involved when D-glucose is treated with the following reagent:
H₂N-OH

Write the reaction involved when D-glucose is treated with the following reagent:

(CH₃CO)₂O