11th Class Physics Thermal Properties of Matter / द्रव्य के तापीय गुण Question Bank

done Kinetic Theory of Gases Conceptual Problems Total Questions - 46

• question_answer1)
  Mention the different ways of increasing the number of molecular collisions per unit time in a gas.
  View Solution play_arrow

• question_answer2)
  What is an ideal gas? Give its main characteristics.
  View Solution play_arrow

• question_answer3)
  Fig. shows the variation of the product PV with respect to the pressure (P) of given masses of three gases. A, B and C. The temperature is kept constant. State with proper arguments which of these gases is ideal.
  View Solution play_arrow

• question_answer4)
  Why do the gases at low temperature and high pressure show large deviations from ideal behaviour?
  View Solution play_arrow

• question_answer5)
  On reducing the volume of a gas at constant temperature, the pressure of the gas increases. Explain it on the basis of kinetic theory.
  View Solution play_arrow

• question_answer6)
  When an automobile travels for a long distance, the air pressure in the tyres increases slightly. Why?
  View Solution play_arrow

• question_answer7)
  When a gas is heated, its temperature increases. Explain it on the basis of kinetic theory of gases.
  View Solution play_arrow

• question_answer8)
  In the upper part of the atmosphere the kinetic temperature of air is of the order of\[\mathbf{1000}\text{ }\mathbf{K}\], event then one feels severe cold there. Why?
  View Solution play_arrow

• question_answer9)
  In the kinetic theory of gases, why do we not take into account the changes in gravitational potential energy of the molecule?
  View Solution play_arrow

• question_answer10)
  What type of motion is associated with the molecules of a gas?
  View Solution play_arrow

• question_answer11)
  Although the root-mean-square speed of gas molecules is of the order of the speed of sound in that gas, yet on opening a bottle of ammonia in one corner of a room its smell takes time in reaching the other corner. Why?
  View Solution play_arrow

• question_answer12)
  On which factors does the average kinetic energy of gas molecules depend: Nature of the gas, temperature, volume?             
  View Solution play_arrow

• question_answer13)
  What do you mean by the r. m. s. speed of the molecules of a gas? Is r. m. s. speed same as the average speed?               
  View Solution play_arrow

• question_answer14)
  The ratio of vapour densities of two gases at the same temperature is 8:9. Compare the r. m. s. velocities of their molecules.              
  View Solution play_arrow

• question_answer15)
  What is the average velocity of the molecules of an ideal gas?
  View Solution play_arrow

• question_answer16)
  Given a sample of \[\mathbf{1}\text{ }\mathbf{c}{{\mathbf{m}}^{\mathbf{3}}}\] of hydrogen and\[\mathbf{1}\text{ }\mathbf{c}{{\mathbf{m}}^{\mathbf{3}}}\]of oxygen both at S.T.P. Which sample has a larger number of molecules?
  View Solution play_arrow

• question_answer17)
  At what temperature does all molecular motion cease? Explain.      Or Molecular motion ceases at zero kelvin. Explain.                                              
  View Solution play_arrow

• question_answer18)
  Why temperature less than absolute zero is not possible?
  View Solution play_arrow

• question_answer19)
  For an ideal gas, the internal energy can only be translational kinetic energy. Explain.
  View Solution play_arrow

• question_answer20)
  At a given temperature, equal masses of monoatomic and diatomic gases are supplied equal quantities of heat. Which of the two gases will suffer a larger temperature rise?
  View Solution play_arrow

• question_answer21)
  Deduce the dimensional formula for R used in the ideal gas equation \[\mathbf{PV}=nRT.\]
  View Solution play_arrow

• question_answer22)
  A box contains equal number of molecules of hydrogen and oxygen. If there is a fine hole in the box, which gas will leak rapidly? Why?
  View Solution play_arrow

• question_answer23)
  The mass of a molecule of krypton is 2.25 times the mass of a hydrogen molecule. A mixture of equal masses of these gases is enclosed in a vessel. Calculate at any temperature the ratio of the root mean square velocities of krypton and hydrogen gases.
  View Solution play_arrow

• question_answer24)
                  A sample of an ideal gas occupies a volume V at a pressure P and absolute temperature T. The mass of each molecule is m. If \[{{k}_{B}}\] is the Boltzmann's constant, then write the expression for the density of the gas.
  View Solution play_arrow

• question_answer25)
  The volume of vessel A is twice the volume of another vessel B, and both of them are filled with the same gas. If the gas in A is at twice the temperature and twice the pressure in comparison to the gas in B, what is the ratio of the gas molecules in A and B?
  View Solution play_arrow

• question_answer26)
  Two gases, each at temperature T, volume V and pressure P are mixed such that the temperature and volume of the mixture are T and V respectively. What would be the pressure of the mixture? Justify your answer on the basis of kinetic theory.
  View Solution play_arrow

• question_answer27)
  The total translational kinetic energy of the molecules of a gas having volume V and pressure P is \[\mathbf{500}\text{ }\mathbf{J}\]. What will be the total translational kinetic energy of the molecules of the same gas occupying the same volume V but exerting a pressure 2P?           
  View Solution play_arrow

• question_answer28)
  Write the equation of state for \[\mathbf{16}\text{ }\mathbf{g}\] of\[{{\mathbf{O}}_{\mathbf{2}}}\].
  View Solution play_arrow

• question_answer29)
  When a gas filled in a closed vessel is heated through\[\mathbf{1}{}^\circ \text{ }\mathbf{C}\], its pressure increases by\[\mathbf{0}.\mathbf{4}%\]. What is the initial temperature of the gas?
  View Solution play_arrow

• question_answer30)
  A gas in a closed vessel is at the pressure \[{{P}_{0}}\] . If the masses of all the molecules be made half and their speeds be made double, then find the resultant pressure.
  View Solution play_arrow

• question_answer31)
  What is evaporation?
  View Solution play_arrow

• question_answer32)
  Why does evaporation cause cooling?
  View Solution play_arrow

• question_answer33)
  Cooking gas containers are kept in a lorry moving with uniform speed. What will be the effect on temperature of the gas molecules?      
  View Solution play_arrow

• question_answer34)
  Should the specific heat of monoatomic gas be less than, equal to or greater than that of a diatomic gas at room temperature? Justify your answer.
  View Solution play_arrow

• question_answer35)
  What is Debye temperature?
  View Solution play_arrow

• question_answer36)
  Equal masses of helium and oxygen gases are given equal quantities of heat. Which gas will undergo a greater temperature rise?
  View Solution play_arrow

• question_answer37)
  A gas is filled in a cylinder fitted with piston at a constant temperature. Explain on the basis of kinetic theory: (i) The pressure of the gas increases by raising the temperature. (ii) On pulling the piston out, the pressure of the gas decreases.
  View Solution play_arrow

• question_answer38)
  There are N molecules of a gas in a container. If the number of molecules is increased to 2N, what will be (i) pressure of the gas, (ii) total energy of the gas and (ii) r. m. s. speed of the gas?
  View Solution play_arrow

• question_answer39)
  Although the velocity of air molecules is nearly \[\mathbf{0}\mathbf{.5 km }{{\mathbf{s}}^{\mathbf{-1}}}\], yet the smell of scent spreads at a much slower rate. Why?
  View Solution play_arrow

• question_answer40)
  When do the real gases obey more correctly the gas equation: \[PV=nRT\]?
  View Solution play_arrow

• question_answer41)
  Explain qualitatively how the extent of Brownian motion is affected by the (a) size of the Brownian particle, (b) density of the medium, (c) temperature of the medium, (d) viscosity of the medium?        
  View Solution play_arrow

• question_answer42)
  For Brownian motion of particles of suspensions in liquids, what should be the typical size of suspended particles? Why should not the size of the particles be too small (say of atomic dimensions \[\mathbf{1}{{\mathbf{0}}^{\mathbf{-10}}}\mathbf{m}\] ) or too large (say of the order of \[\mathbf{1m}\])?      
  View Solution play_arrow

• question_answer43)
  What is the simplest evidence in nature that you can think of to suggest that atoms are not point particles?                              
  View Solution play_arrow

• question_answer44)
  In an experiment, the specific heats of some inert gases (at ordinary temperatures) are measured to be as follows:  

  Gas	Atomic mass \[(u)\]	Specific heat (cal\[{{\mathbf{g}}^{\mathbf{-1}}}{{\mathbf{K}}^{\mathbf{-1}}}\])
  Helium	4.00	0.748
  Neon	20.18	0.147
  Argon	39.94	0.0760
  Krypton	83.80	0.0358
  Xenon	131.3	0.0226

    Try to discover a regularity in the data and explain it on the basis of kinetic energy.             
  View Solution play_arrow

• question_answer45)
  What is meant by molar specific heat of a gas? The molar specific heat of hydrogen \[{{\mathbf{H}}_{\mathbf{2}}}\] is about \[\frac{\mathbf{5}}{\mathbf{2}}\mathbf{R}\]in the temperature range of about \[\mathbf{250}\text{ }\mathbf{K}\] to\[\mathbf{750}\text{ }\mathbf{K}\]. At lower temperatures, molar specific heat of hydrogen decreases to the value typical of monoatomic gases: \[\frac{\mathbf{3}}{\mathbf{2}}\mathbf{R}.\] At higher temperatures, it tends to the value \[\frac{7}{2}\] \[R\]. What do you think is happening?      
  View Solution play_arrow

• question_answer46)
  (a) When a molecule (or an elastic ball) hits a (massive) wall, it rebounds with the same speed. When a ball hits a massive bat held firmly, the same thing happens. However, when the bat is moving towards the ball/the ball rebounds with a different speed. Does the ball move faster or slower? (b) When gas in a cylinder is compressed by pushing in a piston, its temperature rises. Guess at an explanation of this in terms of kinetic theory using (a) above. (c) What happens when a compressed gas pushes a piston out and expands? What would you observe? (d) Sachin Tendulkar uses a heavy cricket bat while playing. Does it help him in any way?     
  View Solution play_arrow