CBSE Chemistry Guess Paper6 Class XII 2010

http://www.cbseguess.com/-------------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com Guess Paper – 2010 Class – XII Subject – Chemistry Time : Three Hours Max. Marks : 70 General Instructions 1. All questions are compulsory. 2. Question nos. 1 to 8 are very short answer questions and carry 1 mark each. 3. Question nos. 9 to 18 are short answer questions and carry 2 marks each. 4. Question nos. 19 to 27 are also short answer questions and carry 3 marks each 5. Question nos. 28 to 30 are long answer questions and carry 5 marks each 6. Use log tables if necessary, use of calculators is not allowed. 1.What is PHBV ? 1 2.What is peptization? 1 3.Write the IUPAC name of [Pt(NH3)2Cl2] 1 4.Write an example of analgesic and antiseptic drug . 1 5.What are anomers? 1 6.What happen when benzaldehyde react with aniline in acidic medium? 1 7.What are ambident nucleophiles ? 1 8.Give an example of Hoffman bromamide reaction? 1 9.An element has a body centered cubic structure with a cell edge of 288 pm.The density Of the element is 7.2 g/cm3.Calculate the no. of unit cells in 208 g of the element. 2 10.Explain the following: 1.F –centre http://www.cbseguess.com/-------------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com 2.A hole 11.Explain the chemistry of lead storage battery while recharging . 2 12.What is disproportionation reaction? Write a chemical reaction to show Disproportionation. 2 13.Explain the classification of polymers on the basis of the molecular forces. 2 14.Give the reasons for 1.Haloalkanes are insoluble in water 2.Haloalkanes react with KCN to form alkyl cyanide as main product while AgCN form Isocyanide as main product. 2 15.Describe the functions of antibiotics and disinfectants. Give one example of each. 2 16.Using valency bond theory predict the shape and magnetic behavior of [Cr(NH3)6]3+ion. 2 17.How will you distinguish between the following chemically: 1. 1-chloro propane and 2-chloro propane 2. Bromobenzene and Bromoethane 2 18.Give the relationship of molecular mass of a nonvolatile solute with osmotic pressure And elevation of boiling point. 2 19.Complete the following : 1. C6H5CN ------------2. C6H5N2Cl +H3PO2+H2O -------------3. C6H5N2Cl -----------------3 http://www.cbseguess.com/-------------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com 20. 1.Write the IUPAC name of 2.Explain the mechanism of hydration of ethane to yield alcohol. 3.Why alcohols have higher B.P than alkyl halide 3 21. 1.What is nucleotide ? 2.What are fat soluble vitamins? 3.Give deficiency diseases of vitamin E and K. 3 22.Complete and balance the following equations : 1. PCl5 +H2O-------------2. KMNO4 +HCl-------------3. S +HNO3----------------3 23.Explain Freundlich adsorption isotherm . 3 24.Write the Nernst equation and calculate the emf of the following cell at 298 K: Cu(s)I Cu2+(0.130M) II Ag+(1.00x10-4M) IAg(s) Given E0 Cu2+ /Cu =+0.34 V and E0 Ag+ /Ag =+0.80 V. 3 25.State briefly the principal which serve as basis for the following operation in metallurgy. 1.Froth –flotation process 2.Zone refining 3.Refining by liquation 3 26.Two elements A and B form compounds having molecular formula AB2 and AB4.When Dissolved in 20 g of C6H6,1 g of AB2 lowers the freezing point by 2.3 K, while 1.0 g of AB4 Lowers it by 1.3 K. The molar dipression constant for benzene is 5.1 KKg/mol.Calculate Atomic masses of A and B. 3 27.What is meant by actenoid contraction ? Discuss the important physical properties http://www.cbseguess.com/-------------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com of actenoids. 3 28. a.Convert the followings 1. Benzene to Benzaldehyde 2.Toluene to Benzoic acid b.Describe the following with suitable chemical reactions: 1. Aldol condensation 2. Cannizzaro reaction 5 c. Write the IUPAC name of Or a. 1.Benzaldehyde to Acetophenone 2.Ethanol to propanone b. Describe the following with suitable chemical reactions: 1.Hell-Volhard – Zelinsky reaction 2. Grignard reaction c. Write the IUPAC name of 29.Give the answer of the following: 1.Draw the structure of XeOF4. 2.Why PCl5 is ionic in the solid state ? 3.Why ammonia is a good complexing agent? 4.Why do argon and fluorine not form compound like Xenon fluorides. 5.Why SF6 is not hydrolysed easily? 5 Or X2 is greenish yellow gas with an offensive smell used in water purification. It partially http://www.cbseguess.com/-------------------------------------------------------------------------------------------------------www.cbseguess.com Other Educational Portals www.icseguess.com | www.ignouguess.com | www.dulife.com | www.magicsense.com Dissolves in water to give a solution which turns blue litmus red. When X2 is passed through NaBr solution,Br2 is obtained. 30.1. Define molecularity .When could molecularity and order of reaction be same and different? 2. Sucrose decomposes in acid solution into glucose and fructose according to the first Order rate law,with t1/2=3.0 h. What fraction of sample of sucrose remains after 8 hrs? 5 or 1.Define order of reaction.Write rate constants for zero and first order reaction. 2.Explain graphically zero and first order reaction. Paper Submitted By : ANUP SHARMA Email Id : anupanjaan@gmail.com Ph No. : +255774520850