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

Among the hydrides of Group-15 elements, which have the maximum basic character?

Among the hydrides of Group-15 elements, which have the highest bond angle?

Among the hydrides of Group-15 elements, which have the maximum reducing character?

Give reasons H₃PO₃ undergoes disproportionation reaction but H₃PO₄ does not.

Give reasons When Cl₂ reacts with the excess of F₂, ClF₃ is formed and not FCl₃.

Although chlorine is an electron withdrawing group, yet it is ortho-, para- directing in electrophilic aromatic substitution reactions. Why?

What is 'copper matte' ?

Account for the following :

Reducing character decreases from SO2 to TeO₂

Account for the following :

BiH₃ is the strongest reducing agent amongst all the hydrides of group 15.

Which of the following is a more stable complex and why ?

Write the structural difference between white phosphorus and red phosphorus.

Account for the following 

The enthalpy of atomisation is lowest for Zn in 3d series of the transition elements.

Write the principle behind the following methods of refining:

Hydraulic washing

Define the following terms:

Pseudo first-order reaction

Define the following terms:

Half-life period of reaction (t_1/2).

Account for the following

Bi(V) is a stronger oxidizing agent than Sb(V).

Account for the following :

N − N single bond is weaker than P − P single bond.

Account for the following :

Noble gases have very low boiling points.

Account for the following :

Sulphur in vapour form exhibits paramagnetic behaviour.

Why is CH₂ = CH - CH₂ - Cl more easily hydrolysed than CH₃ - CH₂ - CH₂ - Cl ?