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

Differentiate between the following:

Adsorption and Absorption

Differentiate between the following:

Lyophobic Sol and Lyophilic Sol

Differentiate between the following:

Lyophobic Sol and Lyophilic Sol

Differentiate between the following:

Multimolecular Colloid and Macromolecular colloid

Why a negatively charged sol is obtained when AgNO₃ solution is added to KI solution?

What is a chelate complex?

Which isomer of C₅H₁₀ gives a single monochloro compound C₅H₉Cl in bright sunlight?

Draw the geometrical isomers of [Co(en)₂Cl₂]²⁺. Which geometrical isomer of [Co(en)₂Cl₂]²⁺ is not optically active and why?

Write the hybridisation and magnetic behaviour of [CoF₆]³⁻.

[Given: Atomic number of Co = 27]

Which of the following molecules has a chiral centre correctly labelled with an asterisk (*)?

The magnetic moment of [NiCl₄]²⁻ is ______.

[Atomic number: Ni = 28]

Which of the following species cannot act as a ligand? Give reason.

The complex [Co(NH₃)₅(NO₂)]Cl₂ is red in colour. Give IUPAC the name of its linkage isomer.

Name the method used for the refining of Nickel metal.

Which would undergo S_N1 reaction faster in the following pair and why?

 Give reasons for the following:

(CH₃)₃C–O–CH₃ on reaction with HI gives (CH₃)₃C–I and CH₃–OH as the main products and not (CH₃)₃C–OH and CH₃–I.

Out of , which is more reactive towards S_N1 reaction and why?

In the extraction of Al, impure Al₂O₃ is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?

Which would undergo S_N2 reaction faster in the following pair and why ?

Indicate the principle behind the method used for the refining of zinc.