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

Which one of the following is a disinfectant?
0.2% solution of phenol or 1% solution of phenol 

Define the following terms with a suitable example of each: 
 Antiseptics 

Account for the following : 
 Ti⁴⁺ is colourless whereas V⁴⁺  is coloured in an aqueous solutions. 

Why do transition metals exhibit higher enthalpy of atomization? 

Define order of reaction. How does order of a reaction differ from molecularity for a complex reaction? 

 A first order reaction is 50% complete in 25 minutes. Calculate the time for 80% completion of the reaction.

How does chemisorption vary with temperature?

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

 Aldehyde as a carbonyl group 

Arrange the following in decreasing order of solubility in water:
\[\ce{(CH3)3N,(CH3)2NH,CH3NH2}\]

How does chemisorption vary with temperature?

Give reasons for the following:

The transition metals generally form coloured compounds.

Which among the following is an ambidentate ligand?

Straight line graph for first order reaction is obtained between ____________.

Which of the following is true about chemisorption?

Adsorption increases when ____________.

Which among the following is a property of physisorption?

Powdered substances are more effective adsorbents than their crystalline forms because ____________.

Which among the following is true for chemisorption?

In physisorption, adsorption is generally ____________.

Chromatography is based on the principle of ____________.