Tiêu đề 13. Kinetic Theory.pdf ✅

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion. B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion. C. If Assertion is True but the Reason is False. D. If both Assertion & Reason are False. 1. Assertion:- Avogadro number is the number of atoms in one gram mole. Reason:- Avogadro number is a dimensionless constant (1) A (2) B (3) C (4) D 2. Assertion :- In equation 1 2 , 3 P =  ms the term  represents density of gas. Reason :- 2 rms RT M  = (1) A (2) B (3) C (4) D 3. One mole of ideal monoatomic gas (  = 5/3) is mixed with one mole of diatomic gas (  = 7/5). What is  for the mixture?  denotes the ratio of specific heat at constant pressure, to that at constant volume :- (1) 3/2 (2) 23/15 (3) 35/23 (4) 4/3 4. The root mean-square speed (rms) of oxygen molecules (O2) at a certain absolute temperature is  . If the temperature is doubled and the oxygen gas dissociates into atomic oxygen, the rms speed would be (1)  (2) 2  (3) 2  (4) 2 2 5. A gas has volume V and pressure P. The total translational kinetic energy of all the molecules of the gas is (1) 3 2 PV only if the gas is mono atomic (2) 3 2 PV only if the gas is diatomic (3) 3 2  PV if the gas is diatomic (4) 3 2 PV in all cases 6. Pressure versus temperature graph of an ideal gas is as shown in figure. Density of the gas at point A is  0 . Density at point B will be:- 7. A gas is filled in a cylinder. Its temperature is increased by 20% on Kelvin scale and volume is reduced by 10%. How much percentage of the gas will leak out :- (1) 30 % (2) 40 % (3) 15 % (4) 25 % 8. The equation of state for 5g of oxygen at a pressure P and temperature T, when occupying a volume V, will be :– (1) PV = 5 RT (2) PV = (5/2) RT (3) PV = (5/16) RT (4) PV = (5/32)RT Where R is the gas constant. 9. The r.m.s. velocity of a gas at a certain temperature is 2 times than that of the oxygen molecules at that temperature. The gas can be :- (1) H2 (2) He (3) CH4 (4) SO2 10. A closed vessel contains 8 gm of oxygen and 7 gm of nitrogen. The total pressure is 10 at mat the given temperature. If all the oxygen is removed from the system without permitting any change in temperature, then the pressure will become (in atmosphere) (1) 70/15 (2) 80/15 (3) 5 (4) 70/8 Kinetic Theory
11. A vessel is partitioned in two equal halves by a fixed diathermic separator. Two different ideal gases are filled in left (L) and right (R) halves. The rms speed of the molecules in L part is equal to the mean speed of molecules in the R part. Then the ratio of the mass of molecules in L part to that of a molecules in R part is - (1) 3 2 (2) 4  (3) 2 3 (4) 3 8  12. , rms v v rms and p v respectively denote the mean speed, root mean square speed and most probable speed of the molecules in an ideal mono atomic gas at absolute temperature T. The mass of the molecules is m. Then :- (1) No molecule can have a speed greater than ( 2vrms ) (2) No molecules can have a speed less than ( 2 ) p v (3) p rms v v v   (4) The average kinetic energy of the molecules is ( ) 3 2 4 mvp 13. A mixture of 2 moles of helium gas (atomic mass= 4 amu) and 1 mole of argon gas (atomic mass= 40 amu) is kept at 300 K in a container. The ratio of the r.m.s. speeds ( ) ( ) helium argon rms rms v v       is (1) 0.32 (2) 0.45 (3) 2.24 (4) 3.16 14. A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is (1) 4 RT (2) 15 RT (3) 9 RT (4) 11 RT 15. Four molecules of a gas have speeds 1, 2, 3 and 4 km/sec. The value of root mean square speed of the gas molecules is :- (1) 15 2 (2) 15 (3) 15 2 (4) 30 2 16. In an adiabatic process, where pressure is increased by 2 % 3 . If 3 , 2 p v C C = then the volume decreases by about :- (1) 4 % 9 (2) 2 % 3 (3) 4% (4) 9 % 4 17. One litre of oxygen at a pressure of 1 atm and two litres of nitrogen at a pressure of 0.5 atm are introduced into a vessel of volume 1L. If there is no change in temperature, the final pressure of the mixture of gas (in atm) is: (1) 1.5 (2) 2.5 (3) 2 (4) 4 18. A gaseous mixture consists of 16 g of helium and16 g of oxygen. The ratio (Cp/ Cv) of the mixture is: (1) 1.4 (2) 1.54 (3) 1.59 (4) 1.62
19. Which of the following statements is correct? (1) A gas has two specific heats only. (2) A gas has infinite number of specific heats. (3) A material will have only one specific heat always. (4) None of the above. 20. The mean kinetic energy of one mole of gas per degree of freedom (on the basis of kinetic theory of gases) is: (1) 1 2 kT (2) 3 2 kT (3) 3 2 RT (4) 1 2 RT 21. The average degree of freedom per molecule of a gas is 6. The gas performs 25 J work, while expanding at constant pressure. The heat absorbed by the gas is (1) 75 J (2) 100 J (3) 150 J (4) 125 J 22. At what temperature average speed of O2 will be 7 4 th       of rms speed of N2 at 47oC– (1)1320 k (2)1500 k (3)273 k (4)1000 k 23. At 27°C rms velocity of H2 gas is 100 m/s find rms velocity of O2 gas at 327°C (1) 100 2 (2) 50 2 (3) 100 (4) 100 2 24. Pressure versus temperature graph of the ideal gas at constant volume V of an ideal gas is shown by a straight line A. Now, pressure P of the gas is doubled and the volume is halved; then the corresponding pressure versus temperature graph will be shown by the line:- (1) A (2) B (3) C (4) None of these 25.Assertion :- The average translational kinetic energy of the molecules in one mole of all deal gases, at the same temperature is the same. 3 . 2  = E RT Reason :- The average kinetic energy of one mole of any ideal gas at temperature T is given by (1) A (2) B (3) C (4) D 26. One grams of H2 at 27°C is mixed with 16 g of O2 at 37°C. The temperature of the mixture is about– (1) 32°C (2) 27°C (3) 37°C (4) 45°C 27. Maxwell distribution function is shown in figure for different gases, which of the following is correct matching? (1) A → Ne, B → O2, C → He (2) A → Ne, B → He, C → O2 (3) A → O2, B → He, C → Ne (4) A → O2, B → Ne, C → He