CBSE Guess > Papers > Question Papers > Class XII > 2005 > Chemistry > Delhi Set-II

CHEMISTRY 2005 (Set-II Delhi)

Except for the following questions, all the remaining questions have been asked in Set I.

Q. 12. Differentiate between a homopolymer and a copolymer. Give one example of each type. 2

Q.18. Explain the following observations:

(i) A beam of light passing through a colloidal solution has a visible path.

(ii) Passing an electric current through a colloidal solution removes colloidal particles from it.

(iii) Ferric hydroxide sol coagulates on addition of a solution of potassium sul-phate. 3

Q. 22. State the reactions taking place when: 3

(i) Nitrobenzene is heated with a mixture of nitric acid and sulphuric acid.

(ii) An alkyl isocyanide is reduced with LAH.

(iii) Bromine water is added to an aqueous solution of aniline.

Q. 24. Describe the following types of substances, giving suitable examples, one each: 3

(a) Antiseptics

(b) Mordant dyes

(c) Biliquid propellants

Q. 26. (a) Assign a reason for each of the following statements:

(i) AICI₃ acts as a catalyst.

(ii) SCI₆ is not known but SF is known

(iii) Not all bonds in a molecule of PCI₅ are equivalent.

(b) Complete the following reaction equations:

(i) XeF₆ + H₂O –>

(ii) Ca(OCI)₂ +HCI –>

Or.

 (a) Assign a reason for each of the following statements:

(i) The +1 oxidation state is more stable than the +3 oxidation state for thallium.

(ii) SF₆ is not easily hydrolyzed.

(iii) In solid state phosphorus pentachloride exists as an ionic solid.

(b) Write structures of the following molecules:

(i) BrF₃

(ii) XeO₃

Q. 27. (a) State the constitutional difference between DNA and RNA Write down the names of the bases produced on hydrolysis of DNA.

(b) Draw simple Fischer projections of D-glucose and L-glucose. Can these be called enantiomers? 3, 2

Or

 (a) Write reactions to show how glucose separately reacts with

(i) NH₂ OH

(ii) HNO₃

(iii) Ammoniacal AgNO₃

(b) What do you understand by (1) Denaturation and (ii) Renaturation of proteins? 3, 2