PUC Science 2nd PUC Class 12 - Karnataka Board PUC Question Bank Solutions

Explain the term with suitable examples:

Aerosol

Explain the term with suitable examples:

Hydrosol

Discuss briefly, giving an example of the role of coordination compounds in medicinal chemistry.

Draw the structure of the given derivative.

Acetaldehydedimethylacetal

Give one example each of lyophobic sol and lyophilic sol.

Discuss briefly, giving an example of the role of coordination compounds in analytical chemistry.

Discuss briefly, giving an example of the role of coordination compounds in extraction/metallurgy of metals.

What are lyophilic and lyophobic colloids ? Which of these sols can be easily coagulated on the addition of small amounts of electrolytes?

What happens when: SO₂ gas is passed through an aqueous solution Fe⁺³ salt?

Define the following terms: Lyophilic colloid

Write the structures of A and B in the following reactions

Write a method by which lyophobic colloids can be coagulated.

Predict the products of the following reactions:

Out of sulphur sol and proteins, which one form multimolecular colloids?

Name the reagents used in the following reactions:

3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of 1.62 K. Calculate the van't Hoff factor and predict the nature of solute (associated or dissociated).

(Given : Molar mass of benzoic acid = 122 g mol⁻¹, K_f for benzene = 4.9 K kg mol⁻¹)

Give reasons for the following observations: Lyophilic sol is more stable than lyophobic sol. 

Define the following term:

Multimolecular colloids

Calculate the amount of benzoic acid (C₆H₅COOH) required for preparing 250 mL of 0.15 M solution in methanol.

19.5 g of CH₂FCOOH is dissolved in 500 g of water. The depression in the freezing point of water observed is 1.0°C. Calculate the van’t Hoff factor and dissociation constant of fluoroacetic acid.