Chemistry-2.Work Book (Phase - II)

Work Book (Phase - II) Subjective: Board Type Questions 1. If the number of moles of a gas were doubled and the pressure and temperature remained the same, what would happen to volume? 2. Can we use vapour densities in place of densities in the formula? 3. What is the nature of R in general gas equation? 4. Both propane and carbon dioxide diffuse at the same rate under identical conditions. Why? 5. Why is Dalton’s law of partial pressure not applicable to a mixture of CO and O2 or NH3 and HCl gases? 6. Why are kinetic energies of hydrogen, carbon dioxide and ethane are the same at the same temperature? 7. Find the value of ‘n’ in 8. H2S acts only as reductant, whereas SO2 acts as oxidant and reductant both. 9. Arrange the following in order of (a) Increasing oxidation number: MnCl2, MnO2, KMnO4 (b) Increasing oxidation number: NH3, N3H, N2O, NO, N2O5 (c) Decreasing oxidation number: HXO, HXO3, HXO2, HXO4 10. Select the species which act as oxidant & reductants in the given reaction 11. Select the species which are oxidised and reduced in the given reaction 12. Which of the following are oxidizing agents and which are reducing agents? Justify your answer with half equations. Br2, Fe3+, . 13. Differentiate bond energy and bond dissociation energy. Illustrate with example? 14. Is it essential to indicate physical state of the reactants and products in the thermochemical reaction? 15. Why heat of solution of electrolytes is sometimes positive and sometimes negative? 16. 12 g carbon in diamond and amorphous forms respectively give different amount of heat on combustion, why? 17. Heat of neutralization for weak acid and strong base is apparently noticed lesser than –13.7 kcal, why? 18. Heat of combustion of C2H6 (–341.1) is greater than the heat of combustion of C2H2 (–310.0) but C2H2 is better fuel, why? 19. Hess’s law is just an extension of the law of conservation of energy. Justify this statement. 20. Why does ice feel cold on touching? Fill in the Blanks 21. The value of PV for 5.6 litre of an ideal gas is ………. RT at NTP. 22. The rate of diffusion of a gas is ………….. proportional to …………………………. or square root of molecular mass. 23. The total energy of one mole of gas (ideal monoatomic) at 27oC is ………… calorie. 24. Oxidation number tells us about the …………of the atom and …………in a molecule. 25. Formation of a positive ion from an atom is ……………………. (Oxidation/reduction) 26. In a balanced ionic equation, the ……………… as well as …………………..must balance. 27. Combustion of F2 in oxygen is …………………….. 28. During evaporation, the entropy of the system ………………………. 29. The total energy of the universe is ……………………… 30. The entropy of the universe is ………………….. continuously. True or False 31. Heat capacity of a diatomic gas is higher than that of a mono–atomic gas. 32. The times of diffusion of equal volumes of two gases, under similar conditions of temperature and pressure, are directly proportional to their molecular masses. 33. In the van der Waal’s equation, The constant a is the actual volume of the gas molecules. 34. A metal in its highest oxidation state acts as oxidant. 35. In a chemical reaction, oxidation is always accompanied by reduction. 36. Oxidation and reduction takes place side by side as they are reversible reaction. 37. A decrease in Gibbs free energy is a measure of maximum work done by the system. 38. 39. A closed system shows exchange of mass and not energy with surroundings. 40. At surroundings, IIT Level Questions 41. Calculate the maximum work done in expanding 16gm of Oxygen at 300K occupying a volume of 5 dm3 isothermally until the volume becomes 25 dm3. 42. A person inhales 640gm of O2 per day. If all O2 is used for converting sugar into CO2 and H2O, how much sucrose (C12H22O11) is consumed in the body in one day and what is the heat evolved? DH¬combustion of Sucrose = – 5645 kJ/mol 43. The enthalpies of the combustion of C2H4(g) and C2H6(g) are – 1410 and – 1560 kJ/mol respectively at temperature at which volume per mole of the gas is 22.4 L. Calculate percentage composition of mixture 20 L of which on combustion releases – 1340kJ of heat. 44. A sample of Magnesium was burnt in air to give a mixture of MgO and Mg3N2. The ash was dissolved in 60 meq of HCl and the resulting solution back titrated with NaOH. 12 meq. of NaOH were required to react the end point. An excess of NaOH was then added and the solution distilled. The ammonia released was then trapped in 100 meq of second acid solutioi. Back titration of this solution required 6 meq. of the base. Calculate the percentage of magnesium burnt to the nitride. 45. The calcium contained in a solution of 1.048 gm of the substance being analysed was precipitated with 25 ml of H2C2O4. The excess of C2O42- in one fourth of the filtrate was back titrated with 5 ml of 0.1025 N KMnO4 solution. To determine the concentration of the H2C2O4 solution taken, it was diluted four fold, the titration of 25 ml of the dilute solution used up 24.1 ml of KMnO4 solution. What is percentage of CaO in the substance being analysed. 46. 25 ml from a stock solution containing NaHCO3 and Na2CO3 was diluted to 250 ml with CO2 free distilled water. 25 ml of the diluted solution when titrated with 0.12 MHCl required 8 ml when phenolphthalein was used as an indicator. When 20 ml of diluted solution was titrated with same acid it required 18 ml when methyl orange was used as an indicator. Calculate concentration of NaHCO3 in the stock solution in gm/litre and in mole / litre. To 100 ml of the stock solution how much NaOH should be added so that all bicarbonate will be converted into carbonate? 47. A mixture consisting of CO(g) and CO2(g) exerts a pressure of 1 atmosphere at 25°C. Enough O2 is added to double the pressure. Subsequent passage of a spark results in a pressure increase to 2.56 atmosphere and temperature increase to 175°C as CO(g) converts to CO2(g). Assuming ideal behaviour, what % of the original mole was CO? 48. A mixture of 10 ml CH4, C2H4 and C2H2 has a vapour density of 11.3. When 30 ml of oxygen are sparked together over aqueous KOH, the volume contracts to 5.5 ml and then disappears when pyrogallol is introduced. If volumes are measured in the same conditions of pressure temperature and humidity; calculate the composition of the original mixture. 49. Deep sea divers usually breathe a mixture of and He gases under water. Estimate the percent composition of volume of He in the mixture at the depth of 25.0 m below sea level such that the partial pressure of is 0.2 atm. Assume ideal gas behaviour. Density of sea water is and acceleration due to gravity is 50. Two flask of equal volume have been joined by a narrow tube of negligible volume. Initially both flasks are at 300 K containing 0.60 mole of O2 gas at 0.5 atm pressure. One of the flask is then placed in a thermostat at 600 K. Calculate final pressure and the number of O2 gas in each flask. Objective: Multiple choice questions with single correct options 1. Equal weights of ethane and hydrogen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by hydrogen is: (A) 1:2 (B) 1:1 (C) 1:16 (D) 15:16 2. A gas in an open container is heated from 27°C to 127°C. The fraction of the original amount of gas left in the container would be (A) (B) (C) (D) 3. There are 6.02´1022 molecules each of N2,O2 and H2. Which are mixed together at 760 mm and 273 K. The mass of the mixture in grams is (A) 6.2 (B) 4.12 (C) 3.09 (D) 7 4. The temperature at which N2 have same root mean square velocity as He at 300 K (A) 300 K (B) 600 K (C) 900 K (D) 2100 K 5. Some mole of O2 diffuse through a small opening in 18 sec. Same number of moles of an unknown gas at same temperature and pressure diffuse through the same opening in 45 sec. Molecular weight of the unknown gas is (A) 32 ´ (B) 32 x (C) (32)2 ´ (D) (32)2 ´ 6. 1 L of a gas weighs 2g at 300 K and 1 atm pressure. If the pressure is reduced to 0.75 atm, at which of the following temperature will 1L of the same gas weighs 1g? (A) 450 K (B) 450°C (C) 800 K (D) 900 K 7. The vessel has nitrogen gas and water vapours at a total pressure of 1 atm. The partial pressure of water vapours is 0.3 atm. The content of this vessel are transferred to another vessel having one third of original volume, completely at the same temperature, the total pressure of the system in the new vessel is (A) 3.0 atm (B) 1 atm (C) 3.33 atm (D) 2.4 atm 8. 380 ml of a gas at 27°C, 800 mm of Hg, weighs 0.455 g. The molecular weight of gas is (A) 27 (B) 28 (C) 29 (D) 30 9. van der Waal’s equation for one mole of CO2 gas at low pressure will be (A) V=RT (B) P(V–b) = RT– (C) P = (D) P = 10. The rms speed of the gas molecules at a temperature 27 K and pressure 1.5 bars is 1.0 × 104 cm/sec. If both temperature and pressure are raised three times the rms speed of the gas will be (A) 9 × 104 cm/sec (B) 3 × 104 cm/sec (C) × 104 cm/sec (D) 1 × 104 cm/sec 11. The order of a gaseous phase reaction for which rate becomes half if volume of container having same amount of reactant is double is (A) 1 (B) 2 (C) 1/2 (D) 1/3 12. At what temperature will H2 molecules have the same r.m.s. velocity as N2 molecules have at 27°C? (A) 21.4 K (B) 42.8 K (C) 10.7 K (D) 85.6 K 13. A 100°C and 1 atm, if the density of liquid water is 1.0 g cm–3 and that of water vapour is 0.0006 g/cm3, then the volume occupied by water molecules in one litre of steam at that temperature is (A) 6 cm3 (B) 60 cm3 (C) 0.6 cm3 (D) 0.06 cm3 14. The ratio between root mean square velocity of H2 at 50 K and that of O2 at 800 K is (A) 4 (B) 2 (C) 1 (D) 1/4 15. A gaseous mixture of 2 moles of A, 3 moles of B, 5 moles of C and 10 moles of D is contained in a vessel. Assuming that gases are ideal and the partial pressure of C is 1.5 atm the total pressure is (A) 3 atm (B) 6 atm (C) 9 atm (D) 15 atm 16. 100 ml of 0.5 N NaOH solutions is added to 10 ml of 3 N H2SO4 solution and 20 ml of 1 N HCl solution. The mixture is (A) Acidic (B) Alkaline (C) Neutral (D) None of these 17. The molarity of 98% H2SO4 (d = 1.8 g/ml) by weight is (A) 6 M (B) 18 M (C) 10 M (D) 4 M 18. If 8.3 ml of a sample of H2SO4 (36 N) is diluted by 991.7 ml of water, the approximate normality of the resulting solution is (A) 0.4 (B) 0.2 (C) 0.1 (D) 0.3 19. If 0.5 mole of BaCl2 is mixed with 0.2 mole of Na3PO4, the maximum number of mole of Ba3(PO4)2 that can be formed is (A) 0.7 (B) 0.5 (C) 0.3 (D) 0.1 20. A 0.1097 gm sample of As2O3 required 26.10 mL of KMnO4 solution for its titration. The molarity of KMnO4 solution is (A) 0.02 (B) 0.04 (C) 0.018 (D) 0.3 21. Which of the following reactions is not a Disproportionation reaction? (A) (B) (C) (D) 22. The equivalent weight of Cu2S (molecular weight = M) in the following reaction is (A) (B) (C) (D) 23. 1.5 litre of a solution of same acid of normality N and 2.5 litres of 2M HCl are mixed together. The resultant solution had a normality 5. The value of N is (A) 6 (B) 10 (C) 8 (D) 4 24. An aqueous solution of 6.3 g oxalic acid dihydrate is made up to 250 ml. The volume of 0.1 N NaOH required to completely neutralize 10 ml of this solution is (A) 40 ml (B) 20 ml (C) 10 ml (D) 4 ml 25. The molarity of 0.56 litre of water vapour at STP is (A) 0.089 M (B) 0.045 M (C) 0.45 M (D) 0.22 M 26. Haemoglobin contains 0.334% of Fe by weight. The molecular weight of haemoglobin is approximately 67200. The number of Fe atoms present in one molecule of haemoglobin is (A) 1 (B) 6 (C) 4 (D) 2 27. For the following reaction sequences Calculate moles of H produced by 10 moles of A (A) 20 (B) 10 (C) 5 (D) 8 28. The molarity of 4 N H2SO4 in the following reaction is (A) 2 M (B) 8 M (C) 32 M (D) 0.5 M 29. With strong oxidising agent, the oxidation product of is and , then what will be the equivalent weight of [K = 39, Fe = 56, C = 12, N = 14] (A) 6.033 (B) 368 (C) 52.57 (D) None of these 30. The equivalent weight of in the following reaction is (A) 63 (B) 189 (C) 126 (D) 84 31. oxidise into , , ( in any reaction, then the equivalent weight of will be (Atomic weight of Fe = 56, C = 12, N = 14 and S = 32) (A) 11.46 (B) 12.46 (C) 14.33 (D) 86 32. What volume strength of 100 ml required for complete reaction of 15.8 g of in basic medium? (A) 5.6 (B) 11.2 (C) 1.86 (D) 3.73 33. What volume of (in ml) at NTP require to completely oxidise 12 mg of assuming that oxidises into and (A) 6.16 (B) 12.32 (C) 1.12 (D) 2.24 34. When 159.50 g of solution is reacted with KI, the liberated iodine requires 100 ml 1 M for complete reaction. What is the percentage purity of Cu in solution? (A) 10% (B) 20% (C) 5% (D) None of these 35. A drop (0.05 ml) of 12 M HCl is spread over a sheet of thin aluminium foil. Assuming that all the acid dissolves through the foil, what will be the area of the aluminium sheet, where the acid is dissolved? (Density of Al = 2.70 g/cm3, thickness of foil = 0.2 mm). (A) (B) (C) (D) 36. The for and are and respectively. The standard enthalpy change (in kJ) for the reaction is (A) 524.1 (B) 41.2 (C) (D) 37. Thermodynamics is concerned with (A) Total energy of a system (B) Energy changes in a system (C) Rate of chemical change (D) Mass changes in nuclear reactions 38. When no heat energy is allowed to enter or leave the system, it is called (A) Isothermal process (B) Reversible process (C) Adiabatic process (D) Irreversible process 39. Warming ammonium chloride with sodium hydroxide in a test tube is an example of (A) Closed system (B) Isolated system (C) Open system (D) None of these 40. The unit of entropy are (A) JK–1 mol–1 (B) KJ–1 mol–1 (C) kJ mol–1 (D) J–1 K–1 mol–1 41. Which is correct equation? (A) (B) (C) (D) 42. At absolute zero, the entropy of a perfect crystal is zero. This is ………...of thermodynamics: (A) Ist law (B) IInd law (C) IIIrd law (D) None of these 43. If a refrigerator door is kept open, then (A) Room is cooled (B) Room gets heated (C) More heat is passed out (D) No effect takes place in the room 44. In a chemical reaction, at 300 K, thus (A) Zero (B) 300 kJ (C) 330 kJ (D) 120 kJ 45. In the evaporation of water, the entropy (A) Decreases (B) Increases (C) Does not change (D) Nothing can be said Instructions: For question 46 to 48 follow the codes given below: (A) Both A & R are correct and R is the correct explanation of A (B) Both A & R are correct, but R is not correct explanation of A (C) A is true but R is false (D) A is false but R is true 46. Assertion (A): All the exothermic reactions are spontaneous at room temperature. Reason (R): In (G = H TS), G becomes negative and negative sign of G indicates spontaneous reaction. 47. Assertion (A): If a solution is 20% by weight of solution, then it is 25% by weight of solvent. Reason (R): Solution also includes weight of solute and thus, pure solvent is 80 g which contains 20 g solute. 48. Assertion (A): In Vander Waal’s equation, Pressure correction, is due to force of attraction between molecules. Reason (R): Due to forces of attraction, volume of molecules can not be neglected. 49. (a) RMS velocity 1. (b) Average velocity 2. (c) Most probable velocity 3. (d) Pressure by kinetic theory of gases 4. a b c d (A) 1 2 3 4 (B) 3 1 4 2 (C) 3 4 1 2 (D) 2 3 4 1 50. (a) Free energy change of a reaction (G) 1. RTlogK (b) Enthalpy change of a reaction in a standard state (H) 2. (c) Entropy change (S) 3. nFE (d) Free energy change of a reaction in a standard state (G) 4. a b c d (A) 3 1 4 2 (B) 1 4 3 2 (C) 2 1 4 3 (D) 3 2 4 1 Multiple choice questions with more than one option correct 51. For an ideal gas (A) (B) (C) (D) 52. Which is /are correct statement (s)? (A) heat of formation of CO2 is 68 kcal mol1 (B) heat of combustion of C(s) is 26 kcal mol1 (C) heat of combustion of CO(g) is 68 kcalmol1 (D) heat of formation of CO(g) is 26 kcal mol1 53. Variation of heat of reaction with temperature is given by Kirchoff’s equation which is (A) (B) (C) (D) none is correct 54. The factors that influence the heat of reaction are (A) the physical state of reactants and products (B) the temperature (C) the pressure or volume (D) the method by which the final products are obtained 55. Boyle’s law may expressed as (A) (dP/dV)T = K/V (B) (dP / dV)T = - K/V2 (C) (dP/dV)T = - K/V (D) V µ 1/P at constant n, T 56. In the equation PV = RT, the value of R will not depend on (A) The nature of the gas (B) The temperature of the gas (C) The pressure of the gas (D) Unit of measurement 57. At constant volume, for a fixed number of moles of a gas, the pressure of the gas increases with rise of temperature due to (A) Increase in average molecular speed (B) Increased rate of collisions amongst molecules (C) Increase in molecular attraction (D) Decrease in mean free path 58. According to kinetic theory of gases, for a diatomic molecule, which is / are not correct? (A) The pressure exerted by the gas is proportional to the mean velocity of the molecule (B) the pressure exerted by the gas is proportional to the root mean square velocity of the molecule (C) the root mean square velocity of the molecule is inversely proportional to the temperature (D) The mean translational kinetic energy of the molecule is proportional to the absolute temperature 59. Which forces (s) of attraction is / are responsible for liquefaction of H2? (A) Coulombic force (B) Dipole force (C) Hydrogen bonding (D) van der Waal’s forces 60. A 5 – L flask containing 1.0 of hydrogen is heated from 300 K to 600 K. Which of the following statements is/are correct? (A) The pressure of the gas increases (B) The rate of collision increases (C) The energy of the gaseous molecules increases (D) The number of mole of the gas increases 61. Which of the following processes would lead to an increase in the average speed of the molecules of an ideal gas system? (A) Decreasing the temperature of the system (B) Compressing the gas with a piston (C) Expanding the gas into a vacuum (D) Heating the system keeping V and P constant 62. 25 mL of 0.50 M H2O2 solution is added to 50 mL of 0.20 M KMnO4 in acid solution. Which two of the following statements are true? (A) 0.010 mole of oxygen is liberated (B) 0.005 mole of KMnO4 does not react with H2O2 (C) 0.0125 g mol of oxygen gas is evolved (D) In the final solution there are only water molecules and Mn+2 ions 63. 10 mL of NaHC2O4 is oxidized by 10 mL of 0.02 M MnO4- in acidic medium. Therefore 10 mL of NaHC2O4 can be neutralized by (A) 10 mL of 0.1 M NaOH (B) 10 mL of 0.02 M NaOH (C) 10 mL of 0.1 N Ca(OH)2 (D) 10 mL of 0.05 M Ba(OH)2 64. H2C2O4 acts as an acid as well as an oxidizing agent. The correct statement (s) about H2C2O4 is / are (A) It forms two series of salt (B) equivalent weight of H2C2O4 as an acid for complete neutralisation and as reductant are same (C) 100 mL of 0.1 M solution of KMnO4 (acid) will be completely reduced by 50 mL of 0.5 M H2C2O4. (D) none of these 65. The internal energy (U) of an ideal gas decreased by the same amount as the work done by the system (A) the process must be adiabatic (B) the process must be isothermal (C) the process must be isobaric (D) the temperature must decrease 66. Which of the following statements is/are incorrect? (A) The entropy of the universe decreases and increases at a periodic rate (B) The entropy of the universe increases and tends towards the maximum value (C) For endothermic spontaneous processes, the total entropy change decreases (D) The entropy of the universe decreases and tends to zero 67. In which of the following cases entropy increases? (A) Solid changing to liquid (B) Expansion of a gas (C) Crystals dissolve (D) Boiling of an egg 68. Which of the following are state properties? (A) Internal energy(U) (B) Volume (V) (C) Heat (q) (D) Enthalpy (H) 69. For the adiabatic expansion of an ideal gas (A) (B) (C) (D) None of these 70. Which of the following is/are true in the case of an adiabatic process? (A) q = W (B) (C) dq = 0 (D) Comprehension Read the paragraph carefully and answer the following questions: During gas analysis, the eudiometer tube filled with mercury is inverted over a trough containing mercury. A known volume of the gas or gaseous mixture to be studied is next introduced, which displaces an equivalent amount of mercury. Next a known amount of oxygen in excess is introduced and the electric spark is passed, whereby the combustible material gets oxidized. The volume of carbon dioxide, water vapour or other gaseous products of combustion are next determined by absorbing them in suitable reagents. The various reagents used for absorbing different gases are turpentine oil alkaline pyragallol 71. 0.2 mole sample of hydrocarbon CxHy yields after complete combustion with excess O2 gas, 0.8 mole of CO2, 1.0 mole of H2O. Hence, hydrocarbon is (A) C4H10 (B) C4H8 (C) C4H5 (D) C8H16 72. A gaseous hydrocarbon requires 6 times its own volume of O2 for complete oxidation and produces 4 times its volume of CO2. What is its formula? (A) C4H10 (B) C4H8 (C) C4H5 (D) C8H16 73. The percentage by volume of C3H8 in a mixture of C3H8 and CH4 is 36.5. Calculate the volume of CO2 produced when 100 ml of mixture is burnt in excess of O2. (A) 273 ml (B) 183 ml (C) 173 ml (D) 193 ml 74. 16 ml of a gaseous aliphatic compound CnH3nOm was mixed with 60 ml O2 and sparked. The gas mixture on cooling occupied 44 ml. After treatment with KOH solution the volume of gas remaining was 12 ml. Deduce the formula of compound. (A) C2H6O (B) C3H8O (C) CH4O (D) None of the above 75. The volume of O2(g) that will be required at NTP for complete combustion of 18.2 litres of propane is (A) 81 litres (B) 91 litres (C) 61 litres (D) 51 litres Read the paragraph carefully and answer the following questions: The process of addition of the known solution from the burette to the measured volume of solution of the substance to be estimated until the reaction between the two is just complete is termed as titration. Titration is classified in following two categories: (a) Acid–base titration (b) Redox titration The acid-base titration is further classified in following three categories: (a) Simple titration (b) Back titration (c) Double titration In simple titration, we can find the concentration of substance with the help of another substance with known concentration, which can react with it. Back titration is used to calculate % purity of a sample. In double titration mainly two indicators, i.e. phenolphthalein (HPh) and methyl orange (MeOH) are used. Suppose, for complete neutralization of Na2CO3, NaHCO3 and NaOH, the amount of standard HCl required is a, b and c ml. The titration of the mixture may be carried by two different methods as summarized below: Mixture Volume of HCl used with Volume of HCl HPh from beginning MeOH from beginning HPh from beginning MeOH orange after first end point NaOH + Na2CO3 (a + c) (For remaining 50% Na2CO3) NaOH + NaHCO3 c + 0 (b + c) c + 0 b (For 100% remaining NaHCO3) Na2CO3 + NaHCO3 (a + b) for remaining 50% of Na2CO3 and 100% NaHCO3 are indicated 76. 150 ml of N/10 HCl is required to react completely with 1.0 g of a sample of limestone. Calculate the percentage purity of CaCO3. (A) 65% (B) 25% (C) 75% (D) 85% 77. 0.63 g of dibasic acid was dissolved in water. The volume of the solution was made 100 ml. 20 ml of this acid solution required 10 ml N/5 NaOH solution. What is the molecular mass of the acid? (A) 63 (B) 126 (C) 252 (D) 128 78. An aqueous solution of 6.3 g of oxalic acid dihydrate is made upto 250 ml. The volume of 0.1 N NaOH required to completely neutralize 10 ml of this solution is (A) 40 ml (B) 20 ml (C) 10 ml (D) 4 ml 79. Mixture of 1 mole BaF2 and 2 moles H2SO4 can be neutralized by (A) 1 mol KOH (B) 2 mol Ca(OH)2 (C) 4 mol NaOH (D) 2 mol KOH 80. A solution contained Na2CO3 and NaHCO3. 15 ml of the solution required 5 ml of N/10 HCl for neutralization using phenolphthalein as an indicator. Addition of methyl orange required a further 15 ml of the acid for neutralization. The amount of Na2CO3 present in the solution is (A) 5.3 g (B) 0.053 g (C) 53 g (D) 4.0053 g ANSWERS TO WORK BOOK Subjective: Board Type Questions 1. Volume becomes doubled as . 2. Yes, 3. 4. Both have same molecular masses. 5. This is because they react with each other. 6. K. E. is independent of the nature of gas. It is equal to 7. Total charge on LHS = Total charge on RHS 8. Oxidation number of S is –2 in H2S and hence it can be oxidized only while. Oxidation number of S is +4 in SO2 which can be reduced as well as oxidized. 9. (a) MnCl2 < MnO2 < KMnO4 (b) NH3 < N3H < N2O < NO < N2O5 (c) HXO4 > HXO3 > HXO2 > HXO 10. In a conjugate pair of redox, the one having lower oxidation number acts as reductant. 11. Thus, C2H4 is oxidised and Br2 is reduced. 12. Oxidants: Br2, Fe3+, Reductants: I–, Na 13. Dissociation energy of CH4, i.e. Average bond energy of C – H bond Since 4 C–H bonds are broken up during dissociation of CH4. 14. Yes, because heat of reaction depends upon physical state of reactants and products. 15. 16. , i.e. heat of combustion depends upon the physical state of reactants. 17. A part of heat produced during neutralization of acid and base is used up in dissociation of weak component (here acid) and thus observed value is lesser than –13.7 kcal. 18. A better fuel is one which has high calorific value, i.e. heat produced by 1 g fuel and not by 1 mole. 19. The law of conservation of energy states that energy can neither be created nor destroyed. Hess’s law also predicts the similar fact that total energy change during the same course of reaction is independent of the path by which reaction is made. 20. The ice has low temperature in comparison to hand and heat flows from hand to ice and we feel the sensation of coldness. Fill in the Blanks 21. 0.25 22. inversely, square root of density 23. 900 24. combining capacity, nature of bonding 25. oxidation 26. atoms, charge 27. endothermic 28. increases 29. constant 30. increasing True or False 31. True 32. False 33. False 34. True 35. True 36. False 37. True 38. True 39. False 40. True IIT Level Questions 41. Since maximum work is done, hence process is reversible Wmax = – 2.303 nRT log = – 2.303 ´ ´ 8.316 ´ 300 log10 = – 2.09 ´ 103 Joule 42. C12H22O11 + 12O2 ¾® 12CO2 + 11H2O DH = –5645 kJ Mole of O2 used per day = = 20 Mole of sucrose used per day = mole = gm = 570gm Heat evolved = 43. Let = xL \ = (20 – x)L mol mol \ ´ 1560 = 1340 \ x = 9.872 L % of ethane (C2H4) = = 49.35% \ % of C2H6 = 50.65% 44. 27.27% 45. 20.99% 46. = 26.2 gm /litre = 0.312 M W = 1.248 gm 47. 69.204% 48. Q CH4= 4 ml, C2H4 = 3 ml, C2H2 = 3 ml 49. % of by volume = % of He by volume = 93% 50. Final pressure in each bulb = 0.66 atm Number of moles of O2 in the flask at 300 K = 0.4 moles Number of moles of O2 in the flask at 600 K = 0.2 moles Objective: Single Correct Questions 1. D 2. A 3. A 4. D 5. A 6. A 7. D 8. B 9. A 10. C 11. A 12. A 13. C 14. C 15. B 16. C 17. B 18. D 19. D 20. B 21. D 22. C 23. B 24. A 25. B 26. C 27. D 28. D 29. A 30. D 31. A 32. A 33. A 34. A 35. B 36. B 37. B 38. C 39. C 40. A 41. B 42. C 43. B 44. D 45. B 46. A 47. A 48. C 49. B 50. D Multiple Correct Questions 51. C, D 52. C, D 53. A, B, C 54. A, B, C 55. B, D 56. A, B, C 57. A, B 58. A, B, C 59. B, D 60. A, B, C 61. B, D 62. B, C 63. A, C, D 64. A, B, C 65. A,D 66. A, C, D 67. A, B, C, D 68. A, B, D 69. A, B, C 70. C, D Comprehension 71. A 72. B 73. C 74. A 75. B 76. C 77. B 78. A 79. B, C 80. B