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

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 ?

Which one of the following is a monosaccharide: 

 starch, maltose, fructose, cellulose

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

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

Write the IUPAC name of the follow

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

 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? 

How does chemisorption vary with temperature?

How does chemisorption vary with temperature?

Give reasons for the following:

The transition metals generally form coloured compounds.

Complete the following reaction:
\[\ce{(C6H5CH2)2Cd + 2CH3COCI}\]

Which of the following is true about chemisorption?

Adsorption increases when ____________.

Which among the following is a property of physisorption?