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

How do you convert the Ethanal to Propanone

Write the structures of the main products in the following reactions :

Write the names and structures of the monomers of the following polymers:

(i) Terylene
(ii) Bakelite
(iii) Buna-S

Which one of the following is a monosaccharide: 

 starch, maltose, fructose, cellulose

Calculate the emf of the following cell at 25°C :

Give reasons for the following observations :

NH₃ gas adsorbs more readily than N₂ gas on the surface of charcoal.

Give two examples of macromolecules that are chosen as drug targets

Account for the following:

Mn²⁺ is more stable than Fe²⁺ towards oxidation to +3 state.

Name the elements of 3d transition series that show maximum number of oxidation states. Why does this happen?

Which transition metal of 3d series has positive E° (M²⁺/M) value and why?

Out of Cr³⁺ and Mn³⁺, which is a stronger oxidising agent and why?

 What is the difference between agonists and antagonists? 

Write structures of compounds A and B of the following reaction : 

Write structures of compounds A and B of the following reaction : 

The decomposition of NH₃ on a platinum surface is a zero-order reaction. If the rate constant (k)  is 4 x 10^-3 ms^-1, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M?

complete the following reaction:

\[\ce{(C6H5CH2)2Cd + 2CH3COCl}\]

Write a chemical reaction to show that the open structure of D-glucose contains the following : 

 Straight chain 

Account for the following : 

o-nitrophenol is more steam volatile than p-nitrophenol.  

Arrange the following:

In increasing order of solubility in water:

C₆H₅NH₂, (C₂H₅)₂NH, C₂H₅NH₂

Which among the following is not true for crystalline solid?