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

Write the IUPAC name of the given compound :

Physisorption is reversible while chemisorption is irreversible. Why ?

Why do transition elements show variable oxidation states ? In 3d series (Sc to Zn), which elements shows the maximum number of oxidation state and why ?

Give reasons for the following observations :

 Powdered substances are more effective  adsorbents.

Account for the following :

Bond angle in NH+4NH4+ is higher than NH₃.

Give simple chemical tests to distinguish between the following pair of compounds:

Benzaldehyde and Benzoic acid

Which component of starch is a branched polymer of α-glucose and insoluble in water?

Using IUPAC norms, write the formula of Hexaamminecobalt(III) sulphate.

 Tendency to show –3 oxidation state decrease from Nitrogn (N) to Bismuth (Bi).

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.