Tiêu đề 2B.THERMODYNAMICS & THERMO CHEMISTRY LEVEL-V(MDP) FINAL.pdf ✅

NISHITH Multimedia India (Pvt.) Ltd., 75 JEE MAINS - CW - VOL - I JEE ADVANCED - VOL - II NISHITH Multimedia India (Pvt.) Ltd., THERMODYNAMICS (ENERGETICS) LEVEL - VI SINGLE ANSWER QUESTIONS 1. If S + O2  SO2 , DH = – 298.2 kJ mole–1 SO2 + 1/2 O2  SO3 DH = – 98.7 kJ mole–1 SO3 + H2O  H2 SO4 , DH = – 130.2 kJ mole–1 H2 + 1/2 O2  H2O, DH = – 287.3 kJ mole–1 the enthalpy of formation of H2 SO4 at 298 K will be - (A) – 814.4 kJ mol|–1 (B) + 814.4 kJ mole–1 (C) – 650.3 kJ mole–1 (D) – 433.7 kJ mole–1 2. A certain mass of gas is expanded from (1L, 10 atm) to (4L, 5 atm) against a constant external pressure of 1 atm. If initial temperature of gas is 300 K and the heat capacity of process is 50 J/°C. Then the enthalpy change during the process is (1L atm ~ 100 J) (A) DH = 15 kJ (B) DH = 15.7 kJ (C) DH = 14.4 kJ (D) DH = 14.7 kJ 3. The standard enthalpy of formation of FeO & Fe2O3 is - 65 kcal mol-1 and - 197kcalmol-1 respectively. A mixture of two oxides contains FeO & Fe2O3 in the mole ratio 2 : 1. If by oxidation, it is changed into a 1 : 2 mole ratio mixture, how much of thermal energy will be released per mole of the initial mixture ? (A) 13.4 kcal/mole (B) 14.6 kcal/mole (C) 15.7 kcal/mole (D) 16.8 kcal/mole 4. An athelete is given 100 g of glucose (C6H12O6 ) of energy equivalent to 1560 kJ. He utilises 50 percent of this gained energy in the event. In order to avoid storage of energy in the body, the weight of water he would need to perspire is- (The enthalpy of evaporation of water is 44 kJ/ mole.) (A) 319 gm (B) 422 gm (C) 293 gm (D) 378 gm 5. Consider the reactions (i) S (rhombic) + 3/2 O2 (g)  SO3 (g), DH1 (ii) S (monoclinic) + 3/2O2 (g)  SO3 (g), DH2 (iii) S (rhombic) + O3 (g)  SO3 (g), DH3 (iv) S (monoclinic) + O3 (g)  SO3 (g), DH4 incorrect statement is (A) DH1 < DH2 < DH4 (magnitude only) (B) DH1 < DH3 < DH4 (magnitude only) (C) DH1 < DH2 = DH3 < DH4 (magnitude only) (D) DH1 + DH4 = DH2 + DH3 6. 10 litres of a monoatomic ideal gas at 0°C and 10 atm pressure is suddenly released to 1 atm pressure and the gas expands adiabatically against this constant pres- sure. The final temperature and volume of the gas respectively are. (A) T = 174.9 K, V = 64.04 litres (B) T = 153 K, V = 57 litres (C) T = 165.4 K, V = 78.8 litres (D) T = 161.2 K, V = 68.3 litres 7. Consider a classroom that is roughly 5 m × 10m × 3m. Initially t = 27°C and P = 1 atm. There are 50 people in an insulated class loosing energy to the room at the average rate of 150 watt per person. How long can they remain in class if the body tempera- ture is 42°C and person feels uncomfort- able above this temperature. Heat capac- ity of air = (7/2) R. (A) 4.34 minutes (B) 5.91 minutes (C) 6.86 minutes (D) 7.79 minutes 8. The increase in internal energy of 1 kg of water at 100°C when it is converted into steam at the same temperature and at 1 atm (100 k Pa) will be [The density of water and steam are 1000 kg/m3 & 0.6 kg/ m3 respectively. The latent heat of vapourisation of water is 2.25 × 106 J/kg.] (A) 2.08 × 106 J (B) 4 × 107 J (C) 3.27 × 108 J (D) 5 × 109 J