Science (English Medium) इयत्ता १२ - CBSE Important Questions for Chemistry

 Write the structures of main products when benzene diazonium chloride (C6 H5 N+2CI−)C6 H5 N2+CI- reacts with the :Cu/HBr

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

Draw the structures of the following :

H₂S2O₇

Account for the following :

HClO₄ is a stronger acid than HClO.

The two O−O bond lengths in the ozone molecule are equal.

Account for the following :

H₃PO₂ is a stronger reducing agent than H₃PO₃.

 Complete and balance the following equations: 
S+H₂SO₄(conc.)  → 

Complete and balance the following equation: 

\[\ce{PCl3 + H2O ->}\] 

Write balanced chemical equations involved in the following reactions:
Chlorine gas reacts with cold and dilute NaOH 

Write balanced chemical equations involved in the following reactions: 
Calcium phosphide is dissolved in water. 

 Draw structures of the following: 
XeF₄ 

 Draw structures of the following: 
`S_2O_8^{2-}`

 Give reactions for the following: 
O – O single bond is weaker than S – S single bond. 

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

 Cl2 acts as a bleaching agent. 

Write one difference between transition elements and p-block elements with reference to variability of oxidation states.

Why phenol undergoes electrophilic substitution more easily than benzene? 

Give a reason for the following :
Ozone is thermodynamically less stable than oxygen. 

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

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

Why phenol undergoes electrophilic substitution more easily than benzene?