Tiêu đề Chemical Thermodynamics.pdf ✅

JEE Advanced JEE (2024) Q1 A monoatomic ideal gas undergoes a process in which the ratio of p to V at any instant is constant and equals to 1. What is the molar heat capacity of the gas? (A) (B) (C) (D) 0 Q2 The standard enthalpies of formation of CO (g), H O(l) and glucose(s) at 25° C are – 400 kJ/mol, –300 kJ/mol and –1300 kJ/ mol, respectively. The standard enthalpy of combustion per gram of glucose at 25° C is (A) + 2900 kJ (B) – 2900 kJ (C) – 16.11 kJ (D) +16.11 kJ Q3 The standard state Gibbs free energies of formation of C (graphite) and C (diamond) at T = 298 K are Δ G°[C(graphite)] = 0 kJ mol Δ G° [C(diamond)] =2.9 kJ mol ) The standard state means that the pressure should be 1 bar, and substance should be pure at a given temperature. The conversion of graphite [C (graphite)] to diamond [C(diamond)] reduces its volume by 2 × 10 ) m mol ). If C(graphite) is converted to C (diamond) isothermally at T = 298 K, the pressure at which C (graphite) is in equilibrium with C (diamond), is [Useful information: 1J = 1 kg m s ), 1 Pa = 1k gm ) s );1 bar =10 Pa (A) 58001 bar (B) 1450 bar (C) 14501bar (D) 29001 bar Q4 One mole of an ideal gas at 300 K in thermal contact with surroundings expands isothermally from 1.0 L to 2.0 L against a constant pressure of 3.0 atm. In this process, the change in entropy of surroundings (ΔS ) in JK is (1L atm = 101.3J) (A) 5.763 (B) 1.013 (C) – 1.013 (D) – 5.763 Q5 The work involved (w) in an isothermal expansion of n moles of an ideal gas from an initial pressure of 'P' atm to final pressure of 1 atm in number of steps such that in every step, the constant external pressure exactly 1 atm less than the initial pressure of gas is maintained, is given as (A) (B) (C) (D) Q6 A gas expands reversibly in a piston cylinder device from V to V , the process being described by PV = a + bV, where P is in Nm , Vis in m and a and b are constants. The work done in the process (w) is (A) (B) (C) (D) Q7 An average human produces about 10 MJ of heat each day through metabolic activity. If a human body were an isolated system of mass 80 kg with the heat capacity of water, what temperature rise would the body experience? Heat capacity of water = 4.2 J/K-g. Chemistry Chemical Thermodynamics 4R 2 3R 2 5R 2 2 2 f –1 f –1 –6 3 –1 2 –2 –1 –2 5 surr –1 – nRT∑ ( ) i=P–1 i=1 1 P+1–i – nRT∑ ( ) i=P i=1 1 P+1–i – nRT∑ ( ) i=P i=1 i P+1–i – nRT∑ ( ) i=P–1 i=1 i P+1–i 1 2 –2 3 aloge ( ) + b( – ) V1 V2 V2 V1 – aloge ( )– b( – ) V2 V1 V2 V1 – aloge ( )– b( – ) V1 V2 V2 V1 aloge ( ) + b( – ) V2 V1 V2 V1
JEE (A) 29.76°C (B) 2.976 K (C) 2.976 × 10 °C (D) 0.029°C Q8 The heat capacity of liquid water is 75.6 J/K- mol, while the enthalpy of fusion of ice is 6.0 kJ/mol. What is the smallest number of ice cubes at 0°C each containing 9.0 g of water needed to cool 500 g of liquid water from 20°C to 0°C? (A) 1 (B) 7 (C) 14 (D) 21 Q9 A student is calculating the work done by 2 mole of an ideal gas in a reversible isothermal expansion shown in the figure. By mistake he calculated the area of the shaded area in the PV graph shown, as work and answered the magnitude of work equal to 49.26 L-atm. What is the correct magnitude of work done by the gas in L-atm? (R = 0.0821 L-atm/K-mol) (A) 49.26 (B) 98.52 (C) 78.63 (D) 34.14 Q10 For an isolated system, the wall/boundary separating the system from surrounding must be (A) rigid (B) impermeable (C) adiabatic (D) diathermal Q11 A liquid is adiabatically expanded from state – I to state – II, suddenly by a single step, as shown in the figure then (A) (B) (C) ΔH = – P V (D) ΔU = – 3P V Q12 Two moles of an ideal gas (C = 1.5 R) is subjected to the following changes in states. A (500 K, 5 bar) C(250 K, 1 bar) D (3 bar) The correct statement(s) is/are (A) The pressure at B is 2.0 bar. (B) The temperature at D is 450 K. (C) ΔH = 1000 R (D) ΔU = 375 R Q13 Which of the following statement(s) is/are true for ideal gas? (A) (–w ) – (–w ) > 0 for isothermal expansion. (B) w > w for isothermal compression. (C) Heat rejected in isothermal process is greater in (n – 1)th stage as compared to nth stage work. (D) Arrow shown in the graph below indicates the decreasing value of γ. Q14 An amount of 4 moles of an ideal monoatomic gas expands adiabatically and reversibly by which its temperature decreases from 47°C to 17°C. Which of the following is/are true? 4 ΔH = 2γPoVo γ−1 ΔU = 3PoVo γ−1 o o o o v,m − → −−−−−−−−−− B Expansion Reversible isothermal − → −−−−−−−− Isochoric cooling − → −−−−−−−−−−− compression Single stage adiabatic CD BC rev irr rev irr
JEE (A) q=0 (B) ΔH = 0 (C) ΔH = –600 cal (D) ΔU = –360 cal Q15 As 1 mole of liquid water is heated from 288 to 298 K, it expands slightly against the atmosphere. Given coefficient of cubic expansion of water is 0.0002/°C; density of water = 1.0 g cm and external pressure = 1 bar. If the magnitude of work for this process is X J, then the value of is Q16 The final volume (in L) of one mole of an ideal gas initially at 27°C and 8.21 atm pressure, if it absorbs 420 cal of heat during a reversible isothermal expansion is (In 2 = 0.7) Q17 A balloon containing air at 27°C and 1 bar initially is filled with air further, isothermally and reversibly till the pressure is 4 bar. If the initial diameter of the balloon is 1 m and the pressure at each stage is proportional to diameter of balloon, the magnitude of work done (in 10 J) is (Nearest Integer) Q18 A quantity of 8 g oxygen gas is expanded isothermally at 27°C from 2 dm to 8 dm at a constant external pressure of 4 bar. If the magnitude of work done in this process is used in lifting a body of mass 40 kg, the height (in metre) up to which the body can be lifted is (g = 10 ms ) Q19 An amount Q of heat is added to a monoatomic ideal gas in a process in which the gas performs a work Q/2 on its surrounding. The molar heat capacity of gas (in cal/K-mol) for the process is | | –3 X 6×10 –4 7 3 3 –2 Android App iOS App PW Website
JEE Answer Key Q1 (A) Q2 (C) Q3 (C) Q4 (C) Q5 (A) Q6 (B) Q7 (A) Q8 (C) Q9 (D) Q10 (A, B, C) Q11 (C, D) Q12 (A, B, C) Q13 (A, C) Q14 (A, C) Q15 (06.00) Q16 (06.00) Q17 (01.00) Q18 (06.00) Q19 (06.00) Android App | iOS App | PW Website