Practice Test


1) The temperature and pressure at which all the three phases of a substance coexist is called the


2) The SI unit of thermal conductivity (K) is


3) The triple point of carbon dioxide is 216.55 K . This temperature on the Fahrenheit scale is


4) A meter long narrow bore held horizontally (and closed at one end) contains a 76 cm long mercury thread which traps a 15 cm column of air. When the tube is held vertically with the open end at the bottom, the length of mercury that flows out is


5) Estimate the ratio of their number of molecules.


6) Estimate the mass densities of Neon to Oxygen in vessel.


7) Obtain the ratio of average kinetic energy per molecule of argon to chlorine.


8) By what percentage should the pressure of a given mass of a gas be increased so as to decrease its volume by 10% at a constant temperature?


9) The equation PV = n R T can safely describe the behavior of a real gas at


10) Boyle's law is applicable in


11) The order of magnitude of the number of nitrogen molecules in an air bubble of diameter 2 mm under ordinary conditions is


12) At a constant pressure, of the following graphs the one which represents the variation of the density of an ideal gas with the absolute temperature T, is


13) A vessel if filled with a gas at a pressure of 76 cm of mercury at a certain temperature. The mass of the gas is increased by 50% by introducing more gas in the vessel at the same temperature. The resultant pressure, in cm of Hg, is


14) Statement 1 : Real gas approaches ideal gas behaviour for low pressure and low temperatures.
Statement 2 : At low pressure, density of gas is very low.


15) Statement 1 : All molecules in a gas move with same speed.
Statement 2 : Average velocity of a gas sample is zero.


16) What is the total kinetic energy of all the molecules of two gases before mixing?


17) If T is the temperature of the mixture, then the total kinetic energy of the two gases after mixing is :


18) The temperature T of the mixture is :


19) The perfect gas equation for 4 gram of hydrogen gas is


20) If the volume of the gas is to be increased by 4 times,


21) In the kinetic theory of gases, which of these statements is/are true?
(i) The pressure of a gas is proportional to the mean speed of the molecules.
(ii) The root mean square speed of the molecules is proportional to the pressure.
(iii) The rate of diffusion is proportional to the mean speed of the molecules.
(iv) The mean translational kinetic energy of a gas is proportional to its Kelvin temperature.


22) The rms speed of a gas molecule is


23) According to kinetic theory of gases, at absolute zero of temperature,


24) Which of the following statements is not in accordance with the assumptions made in kinetic theory?


25) The X-components of velocities of some particles (in km//s) came to be 10, 8, 6, 4, 2, 0, -2, -4, -6, -8, -10. The root mean square (rms) velocity calculated from these data (in km/s) is nearest to


26) The average kinetic energy of hydrogen molecules at NTP is


27) The temperature at which rms velocity of helium molecules is equal to the rms velocity of hydrogen molecules at NTP, is


28) Statement 1 : If we compress a gas sample kept in a container, pressure increases.
Statement 2 : Frequency of collisions of atoms increases.


29) Statement 1 : Internal energy of a gas sample is total kinetic energy of gas.
Statement 2 : There is no interaction force between gas molecules hence potential energy is not defined.


30) Momentum transferred to wall in one collision is


31) Which of the following is not true for a gas sample?


32) Every gas (real gas) behaves as an ideal gas


33) Boyle's law holds for an ideal gas during


34) S.I. unit of universal gas constant is


35) Molecules of a gas behave like


36) At absolute zero temperature, pressure of a gas will be


37) The gas which obeys Boyle's law for maximum range of temperature is


38) The temperature below which a gas should be cooled, before it can be liquified by pressure only is termed as


39) It is possible for a substance to coexist in all three phases in equilibrium, when the substance is at


40) When air is filled in the balloon, the pressure and volume both increases while temperature does not change. Here Boyle's law is not obeyed because


41) For Boyle's law to hold the gas should be


42) Which of the following statements about kinetic theory of gases is wrong


43) If a Vander-Waal's gas expands freely, then final temperature is


44) At NTP, sample of equal volume of chlorine and oxygen is taken. Now ratio of No. of molecules


45) A gas at the temperature 250 K is contained in a closed vessel. If the gas is heated through 1K, then the percentage increase in its pressure will be


46) A cylinder of 5 litre capacity, filled with air at N.T.P. is connected with another evacuated cylinder of 30 litres of capacity. The resultant air pressure in both the cylinders will be


47) Volume of gas become four times if


48) Kinetic theory of gases provide a base for


49) At constant temperature on increasing the pressure of a gas by 5% will decrease its volume by


50) Which law states that effect of pressure is same for all portion


51) When the pressure on 1200 ml of a gas in increased from 70 cm to 120 cm of mercury at constant temperature, the new volume of the gas will be


52) Under which of the following conditions is the law PV = RT obeyed most closely by a real gas


53) That gas cannot be liquified


54) At NTP the mass of one litre of air is 1.293 gm. The value of specific gas constant will be


55) For one gram mol of a gas, the value of R in the equation PV = RT is nearly


56) We write the relation for Boyle's law in the form PV = C when the temperature remains constant. In this relation, the magnitude of C depends upon


57) 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. The expression for the density of gas is (k = Boltzmann’s constant)


58) The product of the pressure and volume of an ideal gas is


59) For ideal gas, which statement is not true


60) Kinetic theory of gases was put forward by


61) When volume of system is increased two times and temperature is decreased half of its initial temperature, then pressure becomes


62) The equation of state for 5 g of oxygen at a pressure P and temperature T, when occupying a volume V, will be


63) The pressure and temperature of two different gases is P and T having the volume V for each. They are mixed keeping the same volume and temperature, the pressure of the mixture will be


64) At a given volume and temperature, the pressure of a gas


65) The rate of diffusion is


66) For matter to exist simultaneously in gas and liquid phases


67) The value of critical temperature in terms of Vander Waal’s constant a and b is


68) Air is filled in a bottle at atmospheric pressure and it is corked at 35°C. If the cork can come out at 3 atmospheric pressure than upto what temperature should the bottle be heated in order to remove the cork


69) 125 ml of gas A at 0.60 atmosphere and 150 ml of gas B at 0.80 atmosphere pressure at same temperature is filled in a vessel of 1 litre volume. What will be the total pressure of mixture at the same temperature


70) Saturated vapour is compressed to half its volume without any change in temperature, then the pressure will be


71) What is the mass of 2 litres of nitrogen at 22.4 atmospheric pressure and 273K


72) The value of PV/T for one mole of an ideal gas is nearly equal to


73) A tyre kept outside in sunlight bursts off after sometime because of


74) In Boyle's law what remains constant


75) In Boyle's law what remains constant


76) The r.m.s. velocity will be greater for


77) In thermal equilibrium, the average velocity of gas molecules is


78) The absolute temperature of a gas is determined by


79) For a gas, the r.m.s. speed at 800 K is


80) The root mean square velocity of a gas molecule of mass m at a given temperature is proportional to


81) A gas is allowed to expand isothermally. The root mean square velocity of the molecules


82) Moon has no atmosphere because


83) Speed of sound in a gas is v and r.m.s. velocity of the gas molecules is c. The ratio of v to c is


84) Which of the following statement is true


85) Two vessels having equal volume contains molecular hydrogen at one atmosphere and helium at two atmospheres respectively. If both samples are at the same temperature, the mean velocity of hydrogen molecules is


86) According to the kinetic theory of gases the r.m.s. velocity of gas molecules is directly proportional to


87) At a given temperature the root mean square velocities of oxygen and hydrogen molecules are in the ratio


88) r.m.s. velocity of nitrogen molecules at NTP is


89) The temperature of an ideal gas is increased from 120 K to 480 K. If at 120 K, the root mean square velocity of the gas molecules is v, at 480 K it becomes


90) The root mean square speed of the molecules of a gas is


91) At a given temperature the r.m.s. velocity of molecules of the gas is


92) The speeds of 5 molecules of a gas (in arbitrary units) are as follows : 2, 3, 4, 5, 6. The root mean square speed for these molecules is


93) At a given temperature the ratio of r.m.s. velocities of hydrogen molecule and helium atom will be


94) Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will


95) The r.m.s. speed of a group of 7 gas molecules having speeds (6, 4, 2, 0, – 2, – 4, – 6) m/s is


96) Molecular motion shows itself as


97) According to the kinetic theory of gases, at absolute temperature


98) The r.m.s. speed of gas molecules is given by


99) If the pressure in a closed vessel is reduced by drawing out some gas, the mean free path of the molecules


100) At constant volume, temperature is increased. Then


101) A monoatomic gas molecule has


102) For an ideal gas of diatomic molecules


103) At constant volume, for different diatomic gases the molar specific heat is


104) The specific heat of an ideal gas is


105) Supposing the distance between the atoms of a diatomic gas to be constant, its specific heat at constant volume per mole (gram mole) is


106) The specific heats at constant pressure is greater than that of the same gas at constant volume because


107) The specific heat of a gas


108) The molar specific heat at constant pressure for a monoatomic gas is


109) Which of the following formulae is wrong


110) The quantity of heat required to raise one mole through one degree Kelvin for a monoatomic gas at constant volume is


111) The specific heat relation for ideal gas is


112) If two moles of diatomic gas and one mole of mono atomic gas are mixed then the ratio of specific heats is


113) The kinetic energy, due to translational motion, of most of the molecules of an ideal gas at absolute temperature T is


114) The ratio of specific heat of a mixture of one mole of helium and one mole of hydrogen gas will be


115) If a gas has n degrees of freedom ratio of specific heats of gas is


116) The degrees of freedom of a stationary rigid body about its axis will be


117) The pressure exerted by the gas on the walls of the container because


118) In kinetic theory of gases, a molecule of mass m of an ideal gas collides with a wall of vessel with velocity V. The change in the linear momentum of the molecule is


119) If the mean free path of atoms is doubled then the pressure of gas will become


120) Relationship between and for a gas is


121) The ratio of mean kinetic energy of hydrogen and oxygen at a given temperature is


122) According to the kinetic theory of gases, total energy of a gas is equal to


123) The average kinetic energy of a gas molecule can be determined by knowing


124) Mean kinetic energy (or average energy) per gm molecule of a monoatomic gas is given by


125) Mean kinetic energy (or average energy) per gm molecule of a monoatomic gas is given by


126) A sealed container with negligible coefficient of volumetric expansion contains helium (a monoatomic gas). When it is heated from 300 K to 600 K, the average K.E. of helium atoms is


127) The time average of the kinetic energy of one molecule of a gas taken over a long period of time


128) The kinetic energy per gm mol for a diatomic gas at room temperature is


129) The translatory kinetic energy of a gas per gm is


130) Read the given statements and decide which is/are correct on the basis of kinetic theory of gases [MP PMT 2003]
(I) Energy of one molecule at absolute temperature is zero
(II) r.m.s. speeds of different gases are same at same temperature
(III) For one gram of all ideal gas kinetic energy is same at same temperature
(IV) For one mole of all ideal gases mean kinetic energy is same at same temperature


131) The translational kinetic energy of gas molecule for one mole of the gas is equal to


132) At 0 K which of the following properties of a gas will be zero


133) At the same temperature and pressure and volume of two gases, which of the following quantities is constant


134) On absolute temperature, the kinetic energy of the molecules


135) On colliding in a closed container the gas molecules


136) Vapour is injected at a uniform rate in a closed vessel which was initially evacuated. The pressure in the vessel


137) The molecules of an ideal gas at a certain temperature have


138) Mean kinetic energy per degree of freedom of gas molecules is


139) In kinetic theory of gases, which of the following statements regarding elastic collisions of the molecules is wrong


140) An ideal gas is filled in a vessel, then


141) 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


142) From the following statements, concerning ideal gas at any given temperature T, select the correct one(s)


143) A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is


144) A gas in container A is in thermal equilibrium with another gas in container B. both contain equal masses of the two gases in the respective containers. Which of the following can be true


145) A closed vessel contains 8gm of oxygen and 7gm of nitrogen. The total pressure is 10 atm at a given temperature. If now oxygen is absorbed by introducing a suitable absorbent the pressure of the remaining gas in atm will be


146) If the intermolecular forces vanish away, the volume occupied by the molecules contained in 4.5 kg water at standard temperature and pressure will be


147) The temperature at which the r.m.s. speed of hydrogen molecules is equal to escape velocity on earth surface, will be


148) Inside a cylinder having insulating walls and closed at ends is a movable piston, which divides the cylinder into two compartments. On one side of the piston is a mass m of a gas and on the other side a mass 2 m of the same gas. What fraction of volume of the cylinder will be occupied by the larger mass of the gas when the piston is in equilibrium ? Consider that the movable piston is conducting so that the temperature is the same throughout


149) A gas mixture consists of 2 mole of oxygen and 4 mole of argon at temperature T. Neglecting all vibrational modes, the total internal energy of the system is


150) A jar contains a gas and few drops of water at T K. The pressure in the jar is 830 mm of mercury. The temperature of jar is reduced by 1%. The saturated vapour pressure of water at the two temperatures are 30 mm and 25 mm of mercury. Then the new pressure in the jar will be


151) Which one the following graphs represents the behaviour of an ideal gas


152) Assertion : In pressure-temperature (P-T) phase diagram of water, the slope of the melting curve is found to be negative.
Reason : Ice contracts on melting to water.


153) Assertion :Equal masses of helium and oxygen gases are given equal quantities of heat. There will be a greater rise in the temperature of helium compared to that of oxygen.
Reason :The molecular weight of oxygen is more than the molecular weight of helium.


154) Assertion :Absolute zero is the temperature corresponding to zero energy.
Reason :The temperature at which no molecular motion cease is called absolute zero temperature.


155) The rate of cooling at 600 K, if surrounding temperature is 300 K is. The rate of cooling at 900 K is


156) A diatomic molecule has how many degrees of freedom


157) The rate of cooling at 600 K, if surrounding temperature is 300 K is. The rate of cooling at 900 K is


158) The temperature at which the average translational kinetic energy of a molecule is equal to the energy gained by an electron in accelerating from rest through a potential difference of 1 volt is


159) The rate of cooling at 600 K, if surrounding temperature is 300 K is. The rate of cooling at 900 K is


160) The latent heat of vaporization of water is 2240 J. If the work done in the process of vaporization of 1 g is 168 J, then increase in internal energy is


161) In the absence of intermolecular forces of attraction, the observed pressure p will be


162) What is the mass of 2 L of nitrogen at 22.4 atm pressure and 273 K?


163) The root mean square velocity of a gas molecule of mass m at a given temperature is proportional to


164) The ratio of the molar heat capacities of a diatomic gas at constant pressure to that at constant volume is


165) The specific heat of an ideal gas is


166) Pressure of an ideal gas is increased by keeping temperature constant. What is the effect on kinetic energy of molecules?


167) A monoatomic gas molecule has


168) The vapour of a substance behaves as a gas


169) The molecular weight of a gas is 44. The volume occupied by 2.2 g of this gas at 0℃ and 2 atm. pressure will be


170) The temperature of a gas is -68℃. At what temperature will the average kinetic energy of its molecules be twice that of at -68℃?


171) A vertical column 50 cm long at 50℃ balances another column of liquid 60 cm long at 100℃. The coefficient of absolute expansion of the liquid is


172) Consider a collection of a large number of particles each with speed v. The direction of velocity is randomly distributed in the collection. What is the magnitude of the relative velocity between a pairs in the collection


173) The translational kinetic energy of gas molecule for one mole of the gas is equal to


174) Cooking gas containers are kept in a lorry moving with uniform speed. The temperature of the gas molecules inside will


175) If temperature of gas increases from 27℃ to 927℃ the K.E. will be


176) For an ideal gas


177) The average kinetic energy of hydrogen molecules at 300 K is E. At the same temperature, the average kinetic energy of oxygen molecules will be


178) The r.m.s. speed of gas molecules is given by


179) A box contains n molecules of a gas. How will the pressure of the gas be effected, if the number of molecules is made 2n


180) Root mean square velocity of a particle is v at pressure P. If pressure is increased two times, then the r.m.s. velocity becomes


181) The amount of heat required to convert 10 g of ice at -10℃ into steam at 100℃ is (in calories)


182) The absolute temperature of a gas is determined by


183) It is seen that in proper ventilation of building, windows must be opened near the bottom and the top of the walls, so as to let pass


184) A container with insulating walls is divided into two equal parts by a partition fitted with a value. One part is filled with an ideal gas at a pressure p and temperature T, whereas the other part is completely evacuated. If the valve is suddenly opened, the pressure and temperature of the gas will be


185) The mean kinetic energy of one mole of gas per degree of freedom (on the basis of kinetic theory of gases) is


186) A polyatomic gas with n degrees of freedom has a mean energy per molecule given by
(N is Avogadro’s number)


187) Two spheres made of same substance have diameters in the ratio1∶2. Their thermal capacities are in the ratio of


188) Volume of gas becomes four times if


189) 22 g of carbon dioxide at 27℃ is mixed in a closed container with 16 g of oxygen at 37℃. If both gases are considered as ideal gases, then the temperature of the mixture is


190) The molar specific heat at constant pressure of an ideal gas is (7/2)R. The ratio of specific heat at constant pressure to that at constant volume is


191) The efficiency of a Carnot engine is 50% and temperature of sink is 500 K. If temperature of source is kept constant and its efficiency raised to 60%, then the required temperature of sink will be


192) A steel ball of mass 0.1 kg falls freely from a height of 10 m of 10 m and bounces to a height of 5.4 m from the ground. If the dissipated energy in this process is absorbed by the ball, the rise in its temperature is


193) At 0 K which of the following properties of a gas will be zero


194) For ideal gas, which statement is not true


195) Under constant temperature, graph between P and 1/V is


196) A jar contains a gas and few drops of water at T K. The pressure in the jar is 830 mm of mercury. The temperature of jar is reduced by 1%. The saturated vapour pressure of water at the two temperatures are 30 mm and 25 mm of mercury. Then the new pressure in the jar will be


197) On 0℃ pressure measured by barometer is 760 mm. What will be pressure at 100℃


198) KE per unit volume is E. The pressure exerted by the gas is given by


199) A cylinder of 5 litre capacity, filled with air at N.T.P. is connected with another evacuated cylinder of 30 litres of capacity. The resultant air pressure in both the cylinders will be


200) Boyle’s law holds for an ideal gas during


201) The temperature of argon, kept in a vessel, is raised by 1℃ at a constant volume. The total heat supplied to the gas is a combination of translation and rotational energies. Their respective shares are


202) The kinetic energy, due to translation motion, of most of the molecules of an ideal gas at absolute temperature T is


203) At temperature T, the r.m.s. speed of helium molecules is the same as r.m.s. speed of hydrogen molecules at normal temperature and pressure. The value of T is


204) The temperature of a gas contained in a closed vessel of constant volume increases by 1℃ when the pressure of the gas is increased by 1%. The initial temperature of the gas is


205) In Boyle’s law what remains constant


206) The degrees of freedom of a molecule of a triatomic gas are


207) A sealed container with negligible coefficient of volumetric expansion contains helium (a monoatomic gas). When it is heated from 300 K to 600 K, the average K.E. of helium atoms is


208) Equation of gas in terms of pressure (P), absolute temperature (T) and density (d) is


209) Air is filled in a bottle at atmospheric pressure and it is corked at 35℃. If the cork can come out at 3 atmospheric pressure than upto what temperature should the bottle be heated in order to remove the cork


210) The kinetic energy of translation of 20 g of oxygen at 47℃ is (molecular wt. of oxygen is 32 g/mol and R = 8.3J/mol/K)


211) If a Vander-Waal’s gas expands freely, then final temperature is


212) To what temperature should the hydrogen at room temperature (27℃) be heated at constant pressure so that the R.M.S. velocity of its molecules becomes double of its previous value


213) The temperature of the hydrogen at which the average speed of its molecules is equal to that of oxygen molecules at a temperature of 31℃, is


214) The pressure is exerted by the gas on the walls of the container because


215) For one gram mol of a gas, the value of R in the equation PV=RT is nearly


216) One mole of a monoatomic ideal gas is mixed with one mole of a diatomic ideal gas. The molar specific heat of the mixture at constant volume is


217) In thermal equilibrium, the average velocity of gas molecules is


218) The heat capacity per mole of water is (R is universal gas constant)


219) Oxygen and hydrogen are at the same temperature T . The ratio of the mean kinetic energy of oxygen molecules to that of the hydrogen molecules will be


220) 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 1 L. If there is no change in temperature, the final pressure of the mixture of gas (in atm) is


221) Molecules of a gas behave like


222) For an ideal gas of diatomic molecules


223) Oxygen boils at (-183℃). The temperature on the Fahrenheit scale is


224) Which one of the following graphs represents the behaviour of an ideal gas?


225) A gas at 27℃ has a volume V and pressure P. On heating its pressure is doubled and volume becomes three times. The resulting temperature of the gas will be


226) S.I. unit of universal gas constant is


227) At 100 K and 0.1 atmospheric pressure, the volume of helium gas is 10 litres. If volume and pressure are doubled, its temperature will change to


228) 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


229) A gas mixture consists of 2 moles of oxygen and 4 moles of argon at temperature T. Neglecting all vibrational moles, the total internal energy of the system is


230) A sample of gas is at 0℃. To what temperature it must be raised in order to double the r.m.s. speed of the molecule


231) A cylinder rolls without slipping down an inclined plane, the number of degrees of freedom it has, is


232) When the temperature of a gas is raised from 27℃ to 90℃, the percentage increase in the r.m.s. velocity of the molecules will be


233) At a given temperature the ratio of r.m.s. velocities of hydrogen molecule and helium atom will be


234) Root mean square speed of the molecules of ideal gas is v. If pressure is increased two times at
constant temperature, the rms speed will become


235) For a gas, the r.m.s. speed at 800 K is


236) At NTP, sample of equal volume of chlorine and oxygen is taken. Now ratio of no. of molecules is


237) If masses of all molecules of a gas are halved and their speeds are doubles, then the ratio of initial
and final pressures is


238) The pressure and temperature of two different gases is P and T having the volume V for each. They are
mixed keeping the same volume and temperature, the pressure of the mixture will be


239) The molar specific heat at constant pressure for a monoatomic gas is


240) The ratio of mean kinetic energy of hydrogen and oxygen at a given temperature is


241) 310 J of heat is required to raise the temperature of 2 mole of an ideal gas at constant pressure from 25°C
to 35°C. The amount of heat required to raise the temperature of the gas through the same range at
constant volume is


242) Which of the following cylindrical rods will conduct maximum heat,when their ends are maintained at a
constant temperature difference?


243) The temperature of a piece of metal is increased from 27°C to 84°C. The rate at which energy is radiated is
increased to


244) A closed gas cylinder is divided into two parts by a piston held tight. The pressure and volume of gas in two parts respectively are (P,5V) and (10P,V). If now the piston is left free and the system undergoes
is on thermal process, then the volume of the gas in two parts respectively are


245) Temperature remaining constant, the pressure of gas is decreased by 20%. The percentage
change in volume


246) Volume-temperature graph at atmospheric pressure for a monoatomic gas (V in m³,T in ℃) is


247) If the volume of the gas containing n number of molecules is V, then the pressure will decrease due to force of intermolecular attraction in the proportion


248) The average momentum of a molecule in an ideal gas depends on


249) Six molecules speeds 2 unit, 5 unit, 3 unit, 6 unit, 3 unit, and 5 unit respectively. The rms speed is


250) Speed of sound in a gas is v and r.m.s. velocity of the gas molecules is c. The ratio of v to c is


251) At what temperature the molecule of nitrogen will have same rms velocity as the molecule of oxygen at 127℃ ?


252) Mean kinetic energy (or average energy) per g molecule of a monoatomic gas is given by


253) A body takes 10 min to cool from 60℃ to 50℃. If the temperature of surroundings is 25℃ and 527℃ respectively. The ratio of energy radiated by P and Q is


254) Kinetic theory of gases provide a base for


255) The temperature of an ideal gas is increased from 27℃ to 927℃. The root mean square speed of its molecules becomes


256) The volume of a gas at 20℃ is 200 ml. If the temperature is reduced to -20℃ at constant pressure, its volume will be


257) The temperature of an ideal gas is reduced from 927℃ to 27℃. The r.m.s. velocity of the molecules becomes


258) According to the kinetic theory of gases, the temperature of a gas is a measure of average


259) The tyre of a motor car contains air at 15℃ . If the temperature increases to 35℃ , the approximate percentage increase is (ignore to expansion of tyre)


260) According to the kinetic theory of gases the r.m.s. velocity of gas molecules is directly proportional to


261) Two moles of oxygen is mixed with eight moles of helium. The effective specific heat of the mixture at constant volume is


262) What is the ratio of specific heats of constant pressure and constant volume for NH3


263) Which one of the following graph is correct at constant pressure


264) The average kinetic energy of a gas molecule can be determined by knowing


265) At what temperature the rms velocity of helium molecules will be equal to that of hydrogen molecules at NTP?


266) The product of the pressure and volume of an ideal gas is


267) A bubble is at the bottom of the lake of depth h. As the bubble comes to sea level, its radius increases three times. If atmospheric pressure is equal to l metre of water column, then h is equal to


268) Two spheres made of same material have radii in the ratio1∶2. Both are at same temperature. Ratio of heat radiation energy emitted per second by them is


269) A horizontal uniform glass tube of 100 cm length sealed at both ends contains 10 cm mercury column in the middle. The temperature and pressure of air on either side of mercury column are respectively 31℃ and 76 cm of mercury. If the air column at one end is kept at 0℃ and the other end at 273℃ , the pressure of air which is at 0℃ is (in cm of Hg)


270) The relationship between pressure and the density of a gas expressed by Boyle’s law, P=KD holds true


271) A closed vessel is maintained at a constant temperature. It is first evacuated and then vapour is injected into it continuously. The pressure of the vapour in the vessel


272) Two balloons are filled, one with pure He gas and the other by air, respectively. If the pressure and temperature of these balloons are same, then the number of molecules per unit volume is


273) A gas at the temperature 250 K is contained in a closed vessel. If the gas is heated through 1K, then the percentage increase in its pressure will be


274) An ideal gas is filled in a vessel, then


275) On giving equal amount of heat at constant volume to 1 mole of a monoatomic and a diatomic gas the rise in temperature


276) At what temperature is the root mean square velocity of gaseous hydrogen molecules equal to that of oxygen molecules at 47℃


277) At what temperature the kinetic energy of gas molecule is half of the value at 27℃?


278) If the temperature of an ideal gas increases three times, then its rms velocity will become


279) A diatomic gas is heated at constant pressure. What fraction of the heat energy is used to increase the thermal energy


280) If mass of He is 4 times that of hydrogen, then mean velocity of He is


281) At what temperature rms speed of air molecules is doubled of that at NTP?


282) Supposing the distance between the atoms of a diatomic gas to be constant, its specific heat at constant volume per mole (gram mole) is


283) Which of the following formula is wrong


284) If the mean free path of atoms is doubled then the pressure of gas will become


285) The specific heat of a gas


286) The root mean square speed of the molecules of a diatomic gas is v. When the temperature is doubled, the molecules dissociate into two atoms. The new root mean square speed of the atom is


287) For a real gas (van der Waal’s gas)


288) Graph of specific heat at constant volume for a monoatomic gas is


289) The time average of the kinetic energy of one molecule of a gas taken over a long period of time


290) The root mean square speed of the molecules of a gas is


291) At constant pressure, which of the following is true?


292) Two moles of monoatomic gas is mixed with three moles of a diatomic gas. The molar specific heat of the mixture at constant volume is


293) At what temperature will the rms speed of air molecules be double than that at NTP?


294) A perfect gas at 27℃ is heated at constant pressure to 327℃. If original volume of gas at 27℃ is V then volume at 327℃ is


295) Universal gas constant is


296) Which of the following statements about kinetic theory of gases is wrong


297) At constant pressure, the ratio of increase in volume of an ideal gas per degree rise in kelvin temperature to it’s original volume is (T= absolute temperature of the gas)


298) The temperature of a given mass is increased from 27℃ to 327℃ . The rms velocity of the molecules increases


299) Mean kinetic energy per degree of freedom of gas molecules is


300) The specific heat relation for ideal gas is


301) A gas at 27℃ temperature and 30 atmospheric pressure is allowed to expand to the atmospheric pressure. If the volume becomes 10 times its initial volume, then the final temperature becomes


302) Volume, pressure and temperature of an ideal gas are V,P and T respectively. If mass of its molecule is m, then its density is [k= boltzmann’s constant]


303) A vessel of volume 4 L contains a mixture of 8 g of oxygen, 14 g of nitrogen and 22 g of carbon dioxide at 27℃. The pressure exerted by the mixture is


304) In kinetic theory of gases, which of the following statements regarding elastic collisions of the molecules is wrong


305) The mean kinetic energy of a gas at 300 K is 100 J. The mean energy of the gas at 450 K is equal to


306) One mole of an ideal monoatomic gas requires 210 J heat to raise the temperature by 10K, when heated at constant temperature. If the same gas is heated at constant volume to raise the temperature by 10K then heat required is


307) At a given temperature the root mean square velocities of oxygen and hydrogen molecules are in the ratio


308) What is an ideal gas?


309) A gas is allowed to expand isothermally. The root mean square velocity of the molecules


310) Saturated vapour is compressed to half is volume without any change in temperature, then the pressure will be


311) The average kinetic energy of a gas molecules is


312) Calculate the ratio of rms speeds of oxygen gas molecules to that of hydrogen gas molecules kept at the same temperature


313) If mass of He atom is 4 times that of hydrogen then mean velocity of He is


314) The ratio of the vapour densities of two gases at a given temperature is 9:8. The ratio of the rms velocities of their molecules is


315) A gas is collected over the water at 25℃. The total pressure of moist gas was 735 mm of mercury. If the aqueous vapour pressure at 25℃ is23.8 mm. Then the pressure of dry gas is


316) 125 ml of gas A at 0.60 atmosphere and 150 ml of gas B at 0.80 atmospheric pressure at same temperature is filled in a vessel of 1 litre volume. What will be the total pressure of mixture at the same temperature


317) The kinetic energy per gmol for a diatomic gas at room temperature is


318) A gas is filled in a closed container and its molecules are moving in horizontal direction with uniform acceleration. Neglecting acceleration due to gravity, the pressure inside the container is


319) The rate of diffusion is


320) r.m.s. velocity of nitrogen molecules at NTP is


321) Mean free path of a gas molecule is


322) If universal gas constant is R, the essential heat to increase from 273 K to 473 K at constant volume for ideal gas of 4 mol is


323) According to Maxwell’s law of distribution of velocities of molecules, the most probable velocity is


324) The equation for an ideal gas is PV=RT, where V represents the volume of


325) At the same temperature and pressure and volume of two gases, which of the following quantities is
constant


326) A closed compartment containing gas is moving with some acceleration in horizontal direction. Neglect effect of gravity. Then the pressure in the compartment is


327) Vapour is injected at a uniform rate in a closed vessel which was initially evacuated. The pressure in the vessel


328) According to the kinetic theory of gases, at absolute temperature


329) For a diatomic gas change in internal energy for unit change in temperature for constant volume is U1 and
U2 respectively. U1:U2 is


330) When volume of system is increased two times and temperature is decreased half of its initial temperature, then pressure becomes


331) The relation between two specific heats of a gas is


332) The quantity of heat required to raise one mole through one degree kelvin for a mono atomic gas at
constant volume is