CHEMISTRY. Time : 3 Hrs. Max. Marks : 70

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1 CHEMISTRY Time : 3 Hrs. Max. Marks : 70 General instructions 1. All questions are compulsory. 2. Q.no. 1-5 are very short answer questions & carry 1 marks each Section-A. 3. Q.no are short answer questions & carry 2 marks each Section-B. 4. Q.no are short answer questions & carry 3 marks each Section-C. 5. Q.no are long answer questions & carry 5 marks each Section-D. SECTION-A (1 MARKS) 1. Name two poisonous gases which can be prepared from chlorine gas. (Write formulae also) 2. Explain Cannizzaro reaction with an example. Explain Aldol Condensation with an example. 3. Name the monomers of Nylon 6, 6. Name the monomers of Dacron. 4. Give the IUPAC name of the following compound O O Write the structural formula of Picric acid. CH 3 C CH 2 C CH 3 5. Write IUPAC names of the following: (a) CH 2 (Cl)COCH(CH 3 )CONH 2 CH 3 OH H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

2 SECTION-B (2 MARKS) 6. What is meant by hydroboration-oxidation reaction? Illustrate it with an example. Write the major product in the following equations : PCl 5 (a) CH 3 CH 2 OH anhyd AlCl 3 C 6 H 5 OH+CH 3 C1 7. Explain: the principle underlying the processes of : (i) Zone refining (ii) Column chromatography 8. Mention one important use of each of the following: (i) Morphine (ii) Aspartame What are antipyretics? Name any one. 9. How will you prepare Nylon-6? Give one of its uses. 10. Represent the cell in which the following reaction takes place Mg(s) + 2Ag + (0.0001M) Mg 2+ (0.130M) + 2Ag(s) Calculate its E (cell) if E (cell) = 3.17 V. 11. Give an example each of fat soluble and water soluble vitamin. Sucrose is a non-reducing sugar but Maltose is reducing sugar. Explain why. 12. The conversion of molecules X to Y follows second order kinetics. If concentration of X is increased to three times how will it affect the rate of formation of Y? H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

3 SECTION-C (3 MARKS) 13. (a) Why does R 3 P = O exist but R 3 N = O does not (R = alkyl group)? Write down the brown ring test for presence of nitrate (also give chemical equations) Arrange the following in the order of property indicated against each set: (a) F 2, I 2, Br 2, Cl 2 (increasing bond dissociation enthalpy). NH 3, AsH 3, SbH 3, BiH 3, PH 3 (decreasing basic strength). (c) HF, HCl, HBr, HI (increasing bond dissociation enthalpy) % of a first order reaction was completed in 60 minutes. When was it half completed? The rate constants of a reaction at 500K and 700K are 0.02sec 1 and 0.07 sec 1 respectively. Calculate the value of activation energy E a (R= J K l mol 1 ). 15. How the following conversions can be carried out? (i) (ii) (iii) Benzyl alcohol to 2-phenyl ethnanoic acid Ethanol to propane nitrile Ethanal to 2-Hydroxy propanoic acid Identify A, B and C in the following reactions : O CH C OH 3 A PCl 5 H 2 Pd/BaSO 4 B C Red P/Br (a) Why do primary amines have higher boiling point than tertiary amines? How is the basic strength of aromatic amines affected by the presence of an electron releasing group on the benzene ring? (c) How is aniline obtained from benzoic acid? Identify A, B and C. CH 3 Cl KCN LiAlH 4 A HNO2 B C O C 5 C H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

4 17. How would you account for the following? (i) The atomic radii of the third series of transition elements are virtually the same as those of the corresponding members of the second series. (ii) The E 0 value for the Mn 3+ / Mn 2+ couple is much more positive than that for Cr 3+ / Cr 2+ couple or Fe 3+ / Fe 2+ couple. (iii) The highest oxidation state of a metal is exhibited in its oxide or fluoride. 18. Define the terms: (a) Reducing Sugars Peptide linkage (c) Nucleotide. 19. What are elastomers? Mention the monomeric units of of Buna-S. (a) Explain the free radical polymerization of ethene. Write the structures of the monomers of the following polymer. 20. Complete and balance the following equations : (i) Cr 2 O OH (ii) MnO 4 + H + + I (iii) MnO 4 + H 2 O + I Complete and balance the following equations : (i) Fe +2 + MnO 4 + H + (ii) KMnO 4 (iii) Na 2 Cr 2 O 7 + KCl 21. (i) Gold number Of haemoglobin is Hence, how much 100 ml of gold sol will CH 6 5 CH 2 CH = CH CH 2 CH 2 CH n require haemoglobin so that gold is not coagulated by 1 ml of 10% NaCI solution. (ii) Name two industrial processes in which heterogeneous catalysts are employed? H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

5 22. In a hydrolysis reaction, 5g ethyl acetate is hydrolyzed in presence of dilute HC1 in 300 minutes. If the reaction is of first order and the initial concentration of ethyl acetate is 22g/L. Calculate the rate constant of the reaction (log 1.29 = 0.11) Two reactions of the same order have equal pre-exponential factors but their activation energies differ by 24.9 kj/mol. Calculate the ratio between the rate constants of these reactions at 27 C (R = J K 1 mol 1 ). 23. Answer the following queries about proteins. (i) How are proteins related to amino acids? (ii) How are amino acids joined together in a protein chain? (iii) When is a protein said to be denatured? Write the equation which proved the following for the structure of glucose : (a) (c) Glucose has a carbonyl group. Glucose has five hydroxyl groups attached to different carbon atoms. Glucose has aldehydic functional group. 24. Silver is electrodeposited on a metallic vessel of total surface area 900 cm 2 by passing a current of 0.5 amp for two hours. Calculate the thickness of silver deposited. [Given: Density of silver = 10.5 g cm 3, Atomic mass of silver = 108 amu, F = 96,500 C mol 1 ] H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

6 SECTION-D (5 MARKS) 25. (a) Write balanced ionic equation for what happens when: (i) Acidified potassium permanganate solution is treated with an oxalate ion in solution. (ii) A sulphide ion is treated with an acidified dichromate ion in solution. Explain giving reasons: (i) Transition metals and many of their compounds show paramagnetic behaviour. (ii) The transition metals generally form coloured compound. (iii) Transition metals and their many compounds act as good catalyst. (a) Complete and Balance the fallowing reactions : (i) Cr 2 O H + + Fe +2 (ii) MnO 2 + KOH + O 2 (iii) MnO H 2 O + I Give reasons : (i) Transition elements exhibit higher enthalpies of atomization (ii) Transition metals form a large number of complex compounds 26. (a) How are the following properties of crystals affected by Schottky and Frenkel defects : (i) Density (ii) Electrical conductivity Iron has a body centred cubic unit cell with the cell dimension of pm. Density of iron is 7.87 g cm 3. Use this information to calculate Avogadro's number. (Atomic mass of Fe = 56.0 ) (a) (i) What is meant by 'doping' in a semiconductor? (ii) What type of substance exhibits antiferromagnetism? Copper crystallises with face centred cubic unit cell. If the radius of copper atom is pm, calculate the density of copper metal. (Atom mass of Cu = and Avogadro's number N A = mol 1 ) H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

7 27. Account for the following : (i) Thermal stability of water is much higher than that of H 2 S. (ii) White phosphorus is more reactive than red phosphorus. Draw the structures of (i) H 3 PO 3 (ii) XeO 3 (iii) H 2 S 2 O 7 (i) In liquid state, hydrogen chloride is a stronger acid than hydrogen fluoride. Why? (ii) (iii) Complete the reactions. (a) I 2 + HNO 3 (conc.) NaOH + Cl 2 (cold and dilute) How would you account for the following? (a) The electron gain enthalpy with negative sign for fluorine is less than that for chlorine, still fluorine is a stronger oxidizing agent than chlorine. Fluorine never acts as the central atom in polyatomic interhalogen compounds. H.O. 92, Rajeev Gandhi Nagar, Kota (Raj.) Mob , , Ph

CHEMISTRY PAPER 1 (THEORY)

CHEMISTRY PAPER 1 (THEORY) CHEMISTRY PAPER 1 (THEY) (Maximum marks: 70) (Time allowed: Three hours) (Candidates are allowed additional 15 minutes for only reading the paper. They must NOT start writing during this time.) ---------------------------------------------------------------------------------------------------------------------