XII-Boards-MODEL SAMPLE PAPER-Chem
9 Jan 2008 00:02:26 IST
XII-Boards-MODEL SAMPLE PAPER-Chem
SET-2
| Time Allotted: 03:00:00 | Maximum Marks: 70 | |
| 1.All questions are compulsory. 2.Marks for each question are indicated against it. 3.Question numbers 1 to 8 are very short-answer questions each of 1 mark. Answer them in about one sentence each. 4.Question numbers 9 to 18 are short-answer questions of 2 marks each. Answer them in not more than 30 words each. 5.Question numbers 19 to 27 are short-answer questions of 3 marks each. Answer them in not more than 40 words each. 6.Question numbers 28 and 30 are long-answer questions of 5 marks each. Answer them in not more than 70 words each. 7.Use Log Tables, If necessary. 8. Please give the explanation for the answer where applicable. 9. To view the answer, click on the Answer link alongside the Question. | ||
| Q 1)What is the difference between sol and gel? 1 Marks | ||
| Q 2)Write the formula of ionization isomer of [Co(NH3)5SO4]Br. 1 Marks | ||
| Q 3)The boiling point of alcohols is more than corresponding isomeric ethers. Why? 1 Marks | ||
| Q 4)Write the monomer of PAN. 1 Marks | ||
| Q 5)Give IUPAC name of the following organic compound CH3CH=CHCH2COCl 1 Marks | ||
| Q 6)Name the vitamin which helps in clotting of blood. 1 Marks | ||
| Q 7)Why aniline is more reactive than benzene? 1 Marks | ||
| Q 8)What are main constituents of dettol? 1 Marks | ||
| Q 9)(i) Name a solid which shows both Frenkel and Schottky defect. (ii) Why Frenkel defect is not found in pure alkali metal halides? (iii) Name point defect a crystal which lowers the density of crystal. (iv) Name the nonstoichiometric point defect responsible for colour in alkali metal halides. 2 Marks | ||
| Q 10) | ||
| Q 11)State Henry's law. Give its two applications also. 2 Marks | ||
| Q 12)What is a secondary cell? Write the reaction/s taking place when a lead storage battery is in use. 2 Marks | ||
| Q 13)An element crystallizes into fcc unit cell type of a structure. The edge length of unit cell is 150 pm.If 150 g of this element have 12 x 1023 atoms, then calculate the density of the element. 2 Marks | ||
In an fcc arrangement of P and Q atoms, P atoms are at the corners of the unit cell. What is the formula of the compound? 2 Marks | ||
| Q 14)Write balance chemical reactions for the following changes:- (i) Potassium permagnate reacts with potassium iodide. (ii) Acidic potassium dichromate reacts with hydrogen sulphide. 2 Marks | ||
| Q 15)Convert the following:- (i) 1-bromopropane to 2-bromopropane. (ii) Propene to 1-nitropropane. 2 Marks | ||
| Q 16)(i) What is the role of sulphur in vulcanization of rubber? (ii) What is PHBV? 2 Marks | ||
| Q 17)Explain the following (i) Swarts reaction (ii) Why chloroform is kept in dark coloured bottles? 2 Marks | ||
| Q 18)(i) Aspirin is an analgesic drug. Why it is useful for heart patients? (ii)What are antifertility drugs? Explain and give one example also. 2 Marks | ||
| Q 19)(i) What would be the value of vant' Hoff factor for dilute solution of K2SO4? (ii) Which will have higher boiling point?0.1 molar solution of glucose or 0.1 molar solution of NaCl in water? (iii) Which of the following is not a colligative property?Osmotic pressure or freezing point? 3 Marks | ||
| Q 20)(a) Zn(s) +2Ag+?Zn2+(aq) +2Ag(s) (i) Represent a galvanic cell in which the above chemical reaction takes place. (ii) Write reactions taking place at electrode and cell reaction. (b) Sn(s)/ Sn2+ (0.04) ? H+ (0.02) / H2/Pt(s) (Given Sn(s)/ Sn2+= -0.16V) Write Nernst equation for above cell. 3 Marks | ||
| Q 21)(a)(i) What happens when little amount of AgNO3 is added to KI solution? (ii) Which of the following electrolyte will be most effective in the coagulation of Sb2S3 sol and why: AlCl3 or BaCl2 or KCl? (b) Why is alum added for purification of water? 3 Marks | ||
| Q 22) Explain the following:- (a) Role of cresols in froth flotation method. (b) Significance of leaching in extraction of silver. (c) Basic difference between roasting and calcination. 3 Marks | ||
| Q 23)Give reasons for the following (a) Transition metals form alloys easily. (c) Cu, Ag & Au are considered as transition metal though they have d10 configuration. 3 Marks | ||
| Q 24)(a) Arrange: CH3OH, (CH3)2CHOH, (CH3)3C-OH in decreasing order of (i) Acidic strength. (ii) Ease of dehydration. (b) Distinguish between ethanol and phenol by one chemical test. 3 Marks | ||
| Q 25)(a) What are interhalogen compounds? Write their general formula/s? Give examples. (b)Arrange the followings as directed: (i) HClO, HClO2, HClO3, HClO4 (Increasing Acidic Strength) 3 Marks | ||
| Q 26)(a) Explain the following:- (i) Use of carbylamine reaction (ii) Methyl amine is a stronger base than ammonia. (b) Write IUPAC name of the following compound (CH3)2-N-CH2-CH3 3 Marks | ||
| Q 27)(a) Write structural differences between:- (i) Cellulose and Amylose. (ii) Sucrose and maltose. (b) Give an example of anomers. 3 Marks | ||
(a) State differences between-- (i) ?-Helix and ?-pleated sheet structure (ii) Primary and secondary structures of protein (b) What is denatured protein? 3 Marks | ||
| Q 28)(i) State any one condition under which a bimolecular reaction is kinetically a first order reaction. (ii) Which will react faster with steam-----1cm x 1cm x 1cm cube of 10 g Magnesium or 10 g powdered magnesium? (iii) The specific rate of reaction is 3.2x10-3 s-1.What is the order of reaction? (iv) Why does rate of reaction not remain constant throughout? (v) How is half life of a first order reaction related to initial concentration of reactants? 5 Marks | ||
| Q 29) Assign reasons for the following: (i) Acidic strength of acids is HF<HCl<HBr<HI. (ii) Oxygen forms ? bonds whereas sulphur does not form ? bonds. (iii) Nitrogen does not form NCl5 but P forms PCl5. (iv) H3PO4 behaves as a dibasic acid. (v) Of the noble gases only Xe forms chemical compounds. 5 Marks | ||
| Q 30) An organic compound (A) molecular formula C5H10O gave positive 2, 4-DNP test but negative Tollen's and iodoform test. On reduction it gives n-pentane. Identify compound (A) and write its IUPAC name. Also write balance chemical reaction for reaction of (A) with NaBH4. 5 Marks | ||
Complete the following reactions and write the name of main products. (i) 2HCHO + NaOH ? (ii) CH3COCH3 + I2 + NaOH ? (iii) CH3CHO + CH3MgBr ? (iv) CH3CH2CONH2 + Br2 + KOH ? (v) 6HCHO + 4NH3 5 Marks | ||
Comments (6)
9 Jan 2008 18:59:03 IST
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Thanx doston.
Keep giving ur comments I will keep giving U sample papers.
Keep giving ur comments I will keep giving U sample papers.
17 Feb 2008 18:39:24 IST
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0 people liked this
Bro give the link na yaar.........Copy karo par fir bhi source to bata do
http://www.extramarks.com
http://www.extramarks.com













But the question papers are still easily readable.