Classs 11 Sample paper, Study notes of Chemistry

Download Classs 11 Sample paper and more Study notes Chemistry in PDF only on Docsity! myCBSEguide.com OC A Complete guide for CBSE students Sample Paper-02 Chemistry (Theory) Class - XI Time allowed: 3 hours Maximum Marks: 70 General Instructions: a) All the questions are compulsory. b) There are 26 questions in total. c) Questions 1 to 5 are very short answer type questions and carry one mark each. d) Questions 6 to 10 carry two marks each. e) Questions 11 to 22 carry three marks each. f) Questions 23is value based question carrying four marks. 8) Questions 24to 26 carry five marks each. h) There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and all three questions in five marks each. You have to attempt only one of the choices in such questions. i) Use of calculators is not permitted. However, you may use log tables if necessary. 1. What will be the volume of ammonia formed if 2L of nitrugen is mixed with 2L of hydrogen at constant temperature and pressure? 2. Give two examples of state functions. 3. Why the molar enthalpy of vapourisation of acetone is less than that of water? 4, How many electrons are present in i6g of metiane? 5. How many grams of Na2CO3 should be dissolved to make 100cc of 0.15M Na2C03? 6. Which of these electrons experience lowest effective nuclear charge? (a) The Br atom containing 35 eiectrons in which 6 electrons are in 2p orbital or (b) 6 electrons in 3p orbital and 5 electrons in 4p orbital. 7. Write structural form:ilas of the following compounds : (a) 3, 4, 4, 5-Tetrameihylheptane (b) 2,5-Dimethyhexane Or Write the structural formula of: (a) O-Ethylanisole (b) 2,3 - Dibromo -1 - phenylpentane 8. (a) How change in velocity of a moving particle change the wavelength of the particle? (b) Give the difference in the angular momentum of an electron present in 3p and 4p orbitals? 9. What is hydride gap? Why is heavy water used in nuclear reactors? 10. Though carbon dioxide is inert and harmless gas, it is thought to be a serious pollutant. Why? Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks Be. ny CBSEguide. com A Complete guide for CBSE students 11. 12. 13. 14, 15. 16. 17. 18. 19, 20. 21. (a)Give the importance of measuring BOD of a water body. (b) What is desirable concentration of fluoride ion pH of drinking water? (c) Give the harmful effect of nitrogen dioxide. (a) Define: (i) Intensive properties (ii) Adiabatic process (b) Derive AG=-TAS,,¢a from the relationship G=H - TS. We know that 75% of solar energy reaching the earth, is absorbed by earth’s surface increases its temperature. The rest of heat radiates back to the atmosphere. Some of the heat is trapped by gases such as CO, CHa, O03, CFC’s and water vapours present in the atmosphere. This causes global warming. (a) Suggest some measures to decrease CO gas in the atmosphere. (b) Give a method to save ozone layer. (c) Will the use of solar energy solve our problems? Comment. Comment on the graph below. Pressure (g] —> Volume (1) —> If the density of 3M solution of NaCl is 1.25g/iuL, calculate the molality of the solution. Calculate the standard enthalpy of formation of one mole of CH30H (1), if the combustion of one mole of methanol takes place at 298 % and 1 atm and after combustion CO2 (g) and H20 (J) are produced and 726 KJ of heat is liberated. Assume that the standard enthalpies of formation of CO2(g) and H20 (1) are - 393 kJ/mol and -286 kJ mol respectively. What are the uses of sodivin carbonate? Describe in detail the expanded octet with suitable examples. How would you prepare alkanes from alkenes? (a) Calculate the concentration of hydroxyl ion in 0.1 M solution of ammonium hydroxide having K,=1.8xi0"°, if Ksp value of two sparingly soluble salts Ni (OH)2 and AgCN are 2x10" and 6.0x10~” respectively. (b) Which salt is more soluble? Or (a) When certain buffer is made by mixing sodium formate and formic acid in water, explain how it neutralizes an addition of a small amount of an acid or a base. (b) When a basic buffer is made by mixing ammonium hydroxide and ammonium nitrate in water, explain how it resists change in its pH on addition of a small amount of an acid ora base. Give the names and formulae of the compounds in the statements given below: Material downloaded from http://myCBSEguide.com and http://onlineteachers.co.in Portal for CBSE Notes, Test Papers, Sample Papers, Tips and Tricks