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

How will you prepare the given compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom.

p-Nitrobenzoic acid

How will you prepare the given compound from benzene? You may use any inorganic reagent and any organic reagent having not more than one carbon atom.

Phenylacetic acid

How will you bring about the following conversion in not more than two steps?

Benazaldehyde to α-Hydroxyphenylacetic acid

Complete the synthesis by giving missing starting material, reagent or product.

Give the uses of freon 12.

How the following conversion can be carried out?

Isopropyl alcohol to iodoform

How the following conversion can be carried out?

Aniline to phenylisocyanide

Give one example each of lyophobic sol and lyophilic sol.

Aqueous copper sulphate solution (blue in colour) gives a bright green solution with aqueous potassium chloride. Explain this experimental result.

Give the uses of DDT.

Give the uses of carbon tetrachloride.

Give the uses of iodoform.

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

Define the following terms: Lyophilic colloid

Write a method by which lyophobic colloids can be coagulated.

Calculate the amount of CaCl₂ (molar mass = 111 g mol⁻¹) which must be added to 500 g of water to lower its freezing point by 2 K, assuming CaCl₂ is completely dissociated. (K_f for water = 1.86 K kg mol⁻¹)

Complete the equation

PbS + O₃ ⟶

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

Write the main product(s) in each of the following reactions:

Account for the following :

Ozone is thermodynamically unstable.