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

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 term:

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 ?

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

 Write the reaction that occurs at anode on electrolysis of concentrated 2 4 H SO using platinum electrodes. 

Predict the main product of the following reactions:
\[\ce{CHO + CH_3CHO->[dil NaOH]}\]

 Write the main product formed when propanal reacts with the following reagents: 
(ii) Dilute NaOH 
`CH_3CH_2CHO + NaOH(dil)-> `

Give a reason for the following: 

 E° value for (Mn²⁺|Mn) is negative whereas for  (Cu²⁺|Cu) is positive. 

Account for the following : 
Acidic character decreases from N₂O₃ to Bi₂O₃ in group 15.

How will you convert the following:
[Ag(CN)₂]⁻ to Ag

Give reasons for the following:
E⁰ value for (Mn³⁺|Mn²⁺) is highly positive than that for (Cr³⁺|Cr²⁺) couple.

Electrochemistry deals with the production of electricity from ____________.