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

Give reasons for the following observations:

Physisorption decreases with increase in temperature.

How would you account for the following: Transition metals form complex compounds.

Write the names and structures of the monomers of the following polymers: Buna-N

Differentiate between adsorbtion and absorption.

Give reasons:

Transition metals show variable oxidation states.

What is the formula of a compound in which the element Y forms ccp lattice and atoms of X occupy 1/3^rd of tetrahedral voids?

What are the transition elements? Write two characteristics of the transition elements.

How would you account for the following : Transition metals form coloured compounds

Define the following term: Primitive unit cells

Account for the following:

Cu⁺ ion is unstable in aqueous solution.

From the given data of E⁰ values, answer the following questions :

(1) Why is `E_(((Cu^(2+))/(Cu)))` value exceptionally positive

(2) Why is `E_(((Mn^(2+))/(Mn)))` value is highly negative as compared to other elements

(3) Which is the stronger reducing agents Cr²⁺ or Fe²⁺ ? Give Reason.

What is the effect of temperature on chemisorption ?

Write the structure of p-methylbenzaldehyde.

How will you distinguish between the following pair of terms?

Crystal lattice and unit cell

Account for the following:

Zn is not considered as a transition element.

Account for the following:

E° value for the Mn³⁺/Mn²⁺ couple is much more positive than that for Cr³⁺/Cr²⁺.

Out of Mn³⁺ and Cr³⁺, which is more paramagnetic and why ?

(Atomic nos. : Mn = 25, Cr = 24)

Why is adsorption always exothermic?

Why does NO₂ dimerise?

Write the structure of 4-chloropentan-2-one.