The average translational energy and the r.m.s. speed of molecules in a sample of oxygen gas at 300 K are 6 . 21 × 10 - 21 J and 484 m/s respectively. The corresponding values at 600 K are nearly (assuming ideal gas behaviour)

12 . 42 × 10 - 21 J , 684 m / s

Physics - Kinetic Theory Gases - Quiz-5

The value of C_V for one mole of neon gas is

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$\frac{1}{2} R$
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$\frac{3}{2} R$
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$\frac{5}{2} R$
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$\frac{7}{2} R$

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

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Exactly equal and its value is 4 cal/mole/°C
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Will be totally different
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Approximately equal and its value is 5 cal/mole/°C
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Same and 3 cal/mole/°C approximately

At constant volume the specific heat of a gas is $\frac{3 R}{2}$ , then the value of $' γ'$ will be

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$\frac{3}{2}$
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$\frac{5}{2}$
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$\frac{5}{3}$
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None of the above

The relation between two specific heats (in cal/mol) of a gas is-

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$C_{P} - C_{V} = \frac{R}{J}$
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$C_{V} - C_{P} = \frac{R}{J}$
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$C_{P} - C_{V} = J$
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$C_{V} - C_{P} = J$

The specific heat of an ideal gas is:

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proportional to $T.$
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proportional to T².
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proportional to T³.
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independent of $T.$

The following sets of values for $C_{V}$ and $C_{P}$ of a gas has been reported by different students. The units are cal/gm-mole-K. Which of these sets is most reliable

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$C_{V} = 3, C_{P} = 5$
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$C_{V} = 4, C_{P} =5$
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$C_{V} = 3, C_{P} = 2$
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$C_{V} = 3, C_{P} = 4.2$

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

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At constant pressure work is done in expanding the gas
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At constant volume work is done in expanding the gas
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The molecular attraction increases more at constant pressure
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The molecular vibration increases more at constant pressure

The specific heat of a gas:

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has only two values $C_{P}$ and $C_{V.}$
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has a unique value at a given temperature.
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can have any value between 0 and $\infty.$
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depends upon the mass of the gas.

For hydrogen gas $C_{P} - C_{V} = a$ and for oxygen gas $C_{P} - C_{V} = b$ where molar specific heats are given. So the relation between a and b is given by-

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$a = 16 b$
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$b = 16 a$
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$a = 4 b$
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$a = b$

For a gas the difference between the two specific heats is 4150 J/kg K. What is the specific heats at constant volume of gas if the ratio of specific heat is 1.4

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8475 J/Kg K
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5186 J/Kg K
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1600 J/Kg K
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10375 J/Kg K

The specific heat of 1 mole of an ideal gas at constant pressure, $C_{P}$ and at constant volume $, C_{V}$ are given. Then-

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$C_{P}$ of hydrogen gas is $\frac{5}{2} R$
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$C_{V}$ of hydrogen gas is $\frac{7}{2} R$
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$H_{2}$ has very small values of $C_{P}$ and $C_{V}$
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$C_{P} - C_{V} =$ 1.99 cal/mole-K for $H_{2}$

One mole of ideal monoatomic gas $(γ = 5 / 3)$ is mixed with one mole of diatomic gas $(γ = 7 / 5)$ . What is $γ$ for the mixture? $γ$ denotes the ratio of specific heat at constant pressure, to that at constant volume

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3/2
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23/15
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35/23
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4/3

A gaseous mixture contains equal number of hydrogen and nitrogen molecules. Specific heat measurements on this mixture at temperatures below 100 K would indicate that the value of $γ$ (ratio of specific heats) for this mixture is

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3/2
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4/3
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5/3
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7/5

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 a molecule in L part to that of a molecule in R part is

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$\sqrt{\frac{π}{4}}$
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$\sqrt{\frac{3}{2}}$
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$\sqrt{\frac{2}{3}}$
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$\frac{3 π}{8}$

One mole of monoatomic gas and three moles of diatomic gas are put together in a container. The molar specific heat $(in J K^{- 1} {mol}^{- 1})$ at constant volume is $(R = 8.3 J K^{- 1} {mol}^{- 1})$

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18.7
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18.9
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19.2
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None of the above

The number of translational degrees of freedom for a diatomic gas is

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2
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3
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5
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6

A gaseous mixture consists of 16g of helium and 16g of oxygen. The ratio $\frac{C_{P}}{C_{V}}$ of the mixture is

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1.4
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1.54
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1.59
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1.62

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

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It loses kinetic energy
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It sticks with the walls
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On collision with the walls there is a change in momentum
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It is accelerated towards the walls

Gas at a pressure $P_{0}$ is contained in a vessel. If the masses of all the molecules are halved and their speeds are doubled, the resulting pressure P will be equal to

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$4 P_{0}$
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$2 P_{0}$
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$P_{0}$
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$\frac{P_{0}}{2}$

Consider a gas with density $ρ$ and $\bar{c}$ as the root mean square velocity of its molecules contained in a volume. If the system moves as whole with velocity v, then the pressure exerted by the gas is

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$\frac{1}{3} ρ {\bar{c}}^{2}$
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$\frac{1}{3} ρ {(c + v)}^{2}$
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$\frac{1}{3} ρ {(\bar{c} - v)}^{2}$
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$\frac{1}{3} ρ {(c^{- 2} - v)}^{2}$

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

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2mV
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mV
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– mV
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Zero

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

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1 : 16
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1 : 8
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1 : 4
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1 : 1

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

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Halved
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Unchanged
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Doubled
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Increased by factor $\sqrt{2}$

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

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2490 joules
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2490 ergs
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830 joules
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124.5 joules

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

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100 J
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3000 J
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450 J
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150 J

Read the given statements and decide which is/are correct on the basis of kinetic theory of gases

(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

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All are correct
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I and IV are correct
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IV is correct
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None of these

At 27°C temperature, the kinetic energy of an ideal gas is $E_{1}$ . If the temperature is increased to 327°C, then kinetic energy would be

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$2 E_{1}$
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$\frac{1}{2} E_{1}$
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$\sqrt{2} E_{1}$
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$\frac{1}{\sqrt{2}} E_{1}$

The average kinetic energy of a gas molecule at $27 ° C$ is $6.21 \times 10^{- 21} J .$ Its average kinetic energy at $227 ° C$ will be

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$52.2 \times 10^{- 21} J$
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$5.22 \times 10^{- 21} J$
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$10.35 \times 10^{- 21} J$
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$11.35 \times 10^{- 21} J$

The average translational energy and the r.m.s. speed of molecules in a sample of oxygen gas at 300 K are $6.21 \times 10^{- 21} J$ and 484 m/s respectively. The corresponding values at 600 K are nearly (assuming ideal gas behaviour)

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$12.42 \times 10^{21} J, 968 m / s$
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$8.78 \times 10^{21} J, 684 m / s$
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$6.21 \times 10^{21} J, 968 m / s$
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$12.42 \times 10^{- 21} J, 684 m / s$

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

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Kinetic energy
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Potential energy
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Vibrational energy
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Density

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Practice Physics Quiz Questions and Answers

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Practice Physics Quiz Questions and Answers

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