CBSE Questions for Class 11 Engineering Physics Kinetic Theory Quiz 16 - MCQExams.com

From the following data of $$\Delta H$$, of the following reactions, 

$$C(s) + \dfrac{1}{2}O_2 (g) \rightarrow CO (g)$$         $$\Delta H = -110 kJ$$

$$C(s) + H_2O (g) \rightarrow CO (g) + H_2 (g)$$    $$\Delta H = 132 kJ$$ 
 
What is the mole composition of the mixture of steam and oxygen on being passed over a coke at 1273 K, keeping temperature constant?              
  • 0.5 : 1
  • 0.6 : 1
  • 0.8 : 1
  • 1 : 1
Three lawn chairs, one made up of aluminium (heat capacity $$= 0.90\ J/K-g$$), one of iron (heat capacity $$= 0.45\ J/K-g$$) and one of tin (heat capacity$$ = 0.60\ J/K-g$$) are painted of the same colour. On a sunny day which chair will be hotter to sit?
  • Iron chair
  • tin chair
  • aluminium chair
  • all, same
One kg of a diatomic gas is at a pressure of $$ 8\times 10^{4}\mathrm{N}/\mathrm{m}^{2}$$. The density of the gas is 4 $$\mathrm{k}\mathrm{g}/\mathrm{m}^{3}$$. The energy of the gas due to its thermal motion will be
  • $$3 \times 10^4 $$ J
  • $$5 \times 10^4$$ J
  • $$6 \times 10^4$$ J
  • $$7 \times 10^4$$ J
Three closed vessels A, B and C are at the same temperature T and contain gases which obey the Maxwellian distribution of velocities, Vessel A contains only $${ O }_{ 2 }$$ B only $${ N }_{ 2 }$$ and C a mixture of equal quantities of $${ O }_{ 2 }$$ and  $${ N }_{ 2 }$$ If the average speed of the $${ O }_{ 2 }$$ molecules in vessel A is $${ V }_{ 1 }$$, that of $$N_{ 2 }$$ molecules in vessel B is $$V_{ 2 }$$ the average speed of the $$O_{ 2 }$$ molecules in vessel C is ( where M is the mass of an oxygen molecule) 
  • $$\left( { V }_{ 1 }+{ V }_{ 2 } \right) /2$$
  • $${ V }_{ 1 }$$
  • $$\left( { V }_{ 1 }{ V }_{ 2 } \right) ^{ 1/2 }$$
  • $$\sqrt { 3kT/M } $$
The value of universal gas constant is $$R=8.3$$ J/K - mol. The value of $$R$$ in atmosphere litre per kelvin mol
  • $$8.12$$
  • $$0.00812$$
  • $$81.2$$
  • $$0.082$$
$$4.48L$$ of an ideal gas at STP requires 12.0 calories to raise its temperature  by $${ 15 }^{ 0 }$$C at constant volume. The $${ C }_{ p }$$ of the gas is:
  • 3 cal
  • 4 cal
  • 7 cal
  • 6 cal
  • 9 cal
For monoatomic gas the relation between pressure of a gas and temperature T is given by $$P_\alpha T^C$$. Then value of C will be : (For adiabatic process)
  • $$\dfrac{5}{3}$$
  • $$\dfrac{2}{5}$$
  • $$\dfrac{3}{5}$$
  • $$\dfrac{5}{2}$$
A certain gas diffuses four times as quickly as oxygen. The molecular weight of the gas is 
  • 2
  • 1
  • 16
  • 1.5
Two contains are filled, each with a different gas,The two containers are at the same temperature.Suppose that the molecular weight of the two gases are $$ M_A and M_B $$ the average moments (in magnitude) of the molecules are related as:
  • $$ P_A = P_B $$
  • $$ P_A = \frac {M_B}{M_A} P_B $$
  • $$ P_ A=\left( \frac { M_ A }{ M_ B } \right)^{1/2} P_B $$
  • $$ P_ A=\left( \frac { M_ B }{ M_ A } \right)^{1/2} P_B $$
The density in grams per liter of ethylene $$ (C_2H_4) $$ at STP is-
  • $$1.25$$
  • $$2.50$$
  • $$3.75$$
  • $$5.25$$
The average speed v and r.m.s. speed $$\bar { v } $$ of the molecules are related as
  • $$\bar { v } =0.92v$$
  • $$\bar { v }^2 =0.29v$$
  • $$\bar { v} =v$$
  • $$C=0.92\bar { C } $$
Which of the following diagrams depicts ideal gas behaviour?
The minimum amount of energy that the reacting molecules must possess at the  time of collisions in order to produce effective collision is called
  • Activation energy
  • Threshold energy
  • Internal energy
  • Free energy.
At NTP the density of a gas is $$1.3 kg\ m^{-3} $$ and the velocity of sound propagation in the gas is$$ 330\ ms^{-1} $$. The degree of freedom of the gas molecule is 
  • 3
  • 5
  • 6
  • 7
A monatomic ideal gas undergoes a process in which the ratio of P to V at any instant is constant and equals toWhat is the molar heat capacity of the gas? 
  • 4R/2
  • 3R/2
  • 5R/2
  • 0
The temperature at which the average speed of oxygen molecules is double that of the same molecules at $$0^oC$$ is _________.
  • 546 K
  • 1092 K
  • 277 K
  • $$1911^oC$$
One gram sample of $$NH_{4}NO_{3}$$ is decomposed in a bomb calorimeter. The temperature of the calorimeter increases by 6.12 K. The heat capacity of the system is 1.23 KJ/g/deg. What is the molar heat of decomposition for $$NH_{4}NO_{3}$$?
  • -7.53 KJ/mol
  • -398 KJ/mol
  • -16.1 KJ/mol
  • -602 KJ/mol
The root mean square speed of hydrogen molecules at 300 K is 1930 m/s then the root mean square speed of oxygen molecules at 900 K will be 
  • $$1930\sqrt{3}m/s$$
  • $$836 m/s$$
  • $$643 m/s$$
  • $$\frac{1930}{\sqrt{3}}m/s$$
Two moles of an ideal monoatomic gas occupies a volume V at $$27^{\circ}C$$. The gas expands adiabatically to a volume 2 V. Calculate (a) the final temperature of the gas and (b) change in its internal energy.
  • $$ 189 K, -2.7 KJ $$
  • $$ 195 K, -2.5 KJ $$
  • $$ 179 K, -2.3 KJ $$
  • $$ 200 K, +2.7 KJ $$
Three closed vessels $$A , B$$ and $$C$$ are at the same temperature $$T$$ and contain gases which obey Maxwell distribution law of velocities. Vessel $$A$$ contains $$\mathrm { O } _ { 2 } , B$$ only $$N _ { 2 }$$ and $$C$$ mixture of equal a quantities of $$\mathrm { O } _ { 2 }$$ and $$\mathrm { N } _ { 2 } .$$ If the average speed of the $$\mathrm { O } _ { 2 }$$ molecules in vessel $$A$$ is $$v _ { 1 }$$ that of $$\mathrm { N } _ { 2 }$$ molecules in vessel $$B$$ is $$v _ { 2 }$$ then the average speed of the $$\mathrm { O } _ { 2 }$$ molecules in vessel $$C$$ is
  • $$\frac { \left( v _ { 1 } + v _ { 2 } \right) } { 2 }$$
  • $$\sqrt { u _ { 1 } v _ { 2 } }$$
  • $$u _ { 1 }$$
  • None of these
A particle of mass $$1 kg$$ is moving in a circular path of radius $$1 m$$ with constant speed of $$1 m/s$$. If the particle moves from positive A to B, then the magnitude of change of velocity is.
1415881_5f11fc27ac7d457c9c7815a48c120bbb.PNG
  • $$1$$ m/s
  • $$\sqrt 2 $$ m/s
  • 2$$\sqrt 2 $$ m/s
  • zero
Helium at $$27^0\,C$$ has a volume of $$8$$ liters. It is suddenly compressed to a volume of $$1$$litre. The temperature of the gas will be $$[\gamma=5/3]$$
  • $$180^0\,C$$
  • $$9327^0\,C$$
  • $$1200^0\,C$$
  • $$927^0\,C$$
A certain mass of gas undergoes a process given by $$dU=\dfrac{dW}{2}$$. If the molar heat capacity of the gas for this process is $$\dfrac{15}{2}R$$, then the gas is :
  • monoatomic
  • polyatomic
  • diatomic
  • data insufficient
A monoatomic gas is kept at room temperature 300 k Calculate the average kinetic energy of gas molecule (use $$k = 1.38 \times 10 ^ { - 23 }$$ MKS unite )
  • $$0.138 e \mathrm { V }$$
  • $$0.062 e \mathrm { V }$$
  • $$0.039 e V$$
  • $$0.013 e V$$
A certain mass of gas undergoes a process given by $$dU = \frac{dW}{2}$$ . If the molar heat capacity of the gas for this process is $$\frac{15}{2} R$$, then the gas is :
  • monoatomaic
  • polyatomic
  • diatomic
  • data insufficient
Find the approx. number of molecules contained in a vessel of volume 7 litres at $$^ { \circ } C$$  at $$1.3 \times 10 ^ { 5 }$$ pascal
  • $$2.4 \times 10 ^ { 23 }$$
  • $$3 \times 10 ^ { 23 }$$
  • $$6 \times 10 ^ { 23 }$$
  • $$4.8 \times 10 ^ { 23 }$$
The heat capacity at constant volume of a sampleof 192 g of gas in a container of volume 80$$\mathrm { L }$$ at atemperature of $$402 ^ { \circ } \mathrm { C }$$ and at a pressure of$$4.2 \times 10 ^ { 5 } \mathrm { Pa }$$ is 124.5$$\mathrm { JK }$$ . The number of thedegrees of freedom of the gas molecules is 
  • 3
  • 5
  • 7
  • 6
The potential energy of the molecules on the free surface of a liquid is
  • Minimum
  • Maximum
  • Zero
  • Infinity
When heat energy of 1500 Joules is supplied to a gasconstant pressure $$2.1 \times 10 ^ { 5 } \mathrm { N } / \mathrm { m } ^ { 2 }$$ , there was an increse in its volume equal to $$2.5 \times 10 ^ { - 3 } \mathrm { m } ^ { 3 }$$ . The increase in intermelenergy of the gas in Joules is - 
  • 450
  • 525
  • 975
  • 2025
An ideal monoatomic gas is initially in state $$1$$ with pressure $$P_{1}=20\ atm$$ and volume $$V_{1}=1500\ cm^{3}$$. It is then taken to state $$2$$ with pressure $$P_{2}=1.5\ P_{1}$$ and volume $$V_{2}=2V_{1}$$. The change in internal energy from state $$1$$ to state $$2$$ is equal to
  • $$2000\ J$$
  • $$3000\ J$$
  • $$6000\ J$$
  • $$9000\ J$$
One mole of an ideal gas with $$= 1.4 ,$$ is adiabatically compressed so that its temperature rises from $$27 ^ { \circ } \mathrm { cto } 35 ^ { \circ } \mathrm { C }$$ . The change in the internal energy of the gas is $$( R = 8.33 \%$$ mol. $$N$$
  • $$- 166 J$$
  • $$ 166 J$$
  • $$- 168J$$
  • $$ 168 J$$
For a certain process, pressure of diatomic gas varies according to the relation $$P = a V ^ { 2 }$$, where $$a$$ is constant. The specific heat of the gas for this process will be
  • $$\frac { 16 R } { 7 }$$
  • $$\frac { 17 R } { 6 }$$
  • $$\frac { 6 R } { 17 }$$
  • $$\frac { 13 R } { 6 }$$
The relation between the gas pressure P and average kinetic energy per unit volume E is
  • $$P = \frac { 1 } { 2 } E$$
  • P = E
  • $$P = \frac { 3 } { 2 } E$$
  • $$P = \frac { 2 } { 3 } E$$
2 moles of a monoatomic gas are expanded to double its initial volume, through a process P/V = constant. If its initial temperature is 300 K, then which of the following is not true.  
  • $$\Delta T = 900 K$$
  • $$\Delta Q = 3200 R$$
  • $$\Delta Q = 3600 R$$
  • W = 900 R
An ideal gas with pressure $$P$$, volume $$V$$ and temperature $$T$$ is expanded isothermally to a volume $$2V$$ and a final pressure $${P}_{I}$$. The same gas is expanded adiabatically to a volume $$2V$$, the final pressure is $${P}_{A}$$. In terms of the ratio of the two specific heats for the gas $$\gamma$$, the ratio $${P}_{I}/{P}_{A}$$ is:
  • $${2}^{\gamma-1}$$
  • $${2}^{1-\gamma}$$
  • $${2}^{\gamma}$$
  • $$2\gamma$$
The kinetic energy associated with per degree of freedom of a molecule is
  • $$\dfrac { 1 }{ 2 } M^{ 2 }_{ rms }$$
  • $$kT$$
  • $$kT/2$$
  • $$3 kT/2$$
When 1 mole of a monoatomic gas expands at constant pressure the ratio of the heat supplied that increases the internal energy of the gas and that used in expansion is
  • $$ \frac{2}{3} $$
  • $$ \frac{3}{2} $$
  • $$0$$
  • $$ \infty $$
p-T diagram of one mole of an ideal monoatomic gas is shown. Processes $$AB$$ and $$CD$$ was adiabatic. Work done in the complete cycle is
1504871_fbc6a0aa57cb44f18b2650f8adedfb77.png
  • $$2.5RT$$
  • $$-2RT$$
  • $$1.5RT$$
  • $$-3.5RT$$
A vessel of volume $$  V=5.0  $$ liters contains 1.4 $$ \mathrm{g}  $$ of nitrogen at temperature $$  T=1800 \mathrm{K}  $$ . Find the pressure of the gas if 30$$  \%  $$ of its molecules are dissociated into atoms at this temperature.
  • $$ 1.94 \times 10^{2} N / m^{2} $$
  • $$ 1.94 \times 10^{3} N / m^{2} $$
  • $$ 2.84 \times 10^{2} N / m^{2} $$
  • None of these
A vessel of volume $$5000 { cm }^{ 3 }$$ contains (1/20) mole of molecular nitrogen at 1800 K. If 30% of the molecules are now dissociated the pressure inside the vessel in Pa will be-
  • $$1.49\times { 10 }^{ 5 }$$
  • $$1.94\times { 10 }^{ 5 }$$
  • $$2.25\times { 10 }^{ 5 }$$
  • $$3.78\times { 10 }^{ 5 }$$
One mole of a perfect gas in a cylinder fitted with a piston has a pressure P, volume V and temperature is increased by 1 K keeping pressure constant , the increase in volume is
  • $$\dfrac { 2V }{ 273 } $$
  • $$\dfrac { 2V }{ 91 }$$
  • $$\dfrac { V }{ 273 } $$
  • V
If distance between the gas molecules is doubled on constant temperature , then pressure . 
  • $$\dfrac{P}{16}$$
  • $$\dfrac{P}{8}$$
  • $$\dfrac{P}{4}$$
  • $$\dfrac{P}{2}$$
The mean kinetic energy of one mole of gas per degree of freedom (on the basis of kinetic theory of gases) is:
  • $$

    \frac { 1 } { 2 } k T

    $$
  • $$

    \frac { 3 } { 2 } k T

    $$
  • $$

    \frac { 3 } { 2 } R T

    $$
  • $$

    \frac { 1 } { 2 } R T

    $$
The potential energy function for the force between two atoms in a diatomic molecule is approximately given by $$ U (X) = a/x^{12} - b/x^6 $$ where a and b are constant and x is the distance between atoms.If the dissociation energy of the molecule is $$ D = [U(x = \infty )] = U_{equilibrium}$$. D is
  • $$ b^2 / 12a $$
  • $$ b^2 / 4a $$
  • $$ b^2 /6a $$
  • $$ b^2/2a $$
Two containers  $$A$$  and  $$B$$  contain molecular gas at same temperature with masses of molecules are  $${ m }_{ { { A } } }$$  and  $${ m }_{ { { B } } }$$   then relation of momentum  $${ P }_{ { A } }$$  and  $${ P }_{ { { B } } }$$  will be
  • $${ P }_{ { { A } } }={ P }_{ { { B } } }$$
  • $$P _ { A } = \left( \dfrac { m _ { A } } { m _ { B } } \right) ^ { 1 / 2 } P _ { B }$$
  • $$P _ { A } = \left( \dfrac { m _ { B } } { m _ { A } } \right) ^ { 1 / 2 } P _ { B }$$
  • $$P _ { A } = \left( \dfrac { m _ { A } } { m _ { B } } \right) P _ { B }$$
A balloon weighting 50kg is filled with 685.2kg of helium at 1 atm pressure and at $${ 25 }^{ o }$$C. What will be its displaced 51087 kg of air ?
  • 4372.8 kg
  • 43.728 kg
  • 4843.2 kg
  • None
The mass of glucose that should be dissolved in 100 g of water in order to produce same lowering of vapour pressure as is produced by dissolving 1 g of urea (mol. Mass = 60) in 50 g of water is : (Assume dilute solution in both cases) 
  • 1 g
  • 2 g
  • 6 g
  • 12 g
At what temperature does the average translational kinetic energy of a molecule in a gas become equal to kinetic energy of an electron accelerated from rest through a potential difference of $$1$$ volt? ($$k=1.38\times{!0}^{-23}J/k$$)
  • $$3770K$$
  • $$7370K$$
  • $$7730K$$
  • $$7330K$$
One mole  of gas ''A'' and 2 moles of S$${ O }_{ 2 }$$ are placed in a container,gaseous can be:
  • $${ H }_{ 2 }$$
  • $$C{ H }_{ 4 }$$
  • He
  • $${ D }_{ 2 }$$
The molecular weights of $$O_2$$ and $$N_2$$ are 32 and 28 respectively. At $$15^0$$C, the pressure of 1 gm will be the same as that of 1 gm in the same bottle at the temperature.
  • $$-21^0$$C
  • $$-13^0$$C
  • $$15^0$$C
  • $$56.4^0$$C
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