Back to Quizzes

Complete Syllabus Question Paper
Grade 11 : Physics - Kinetic Theory (Set 4)— Questions & Detailed Solutions
Q1
A sample of Nitrogen gas ($N_2$, molar mass $M = 28\text{ g/mol}$) is initially at an absolute temperature of 300 K with a root-mean-square speed $v_{rms} = 500m/s$. The sample is heated at constant volume to 1200 K.
What is the new root-mean-square speed ($v_{rms}'$) of the Nitrogen gas molecules at 1200 K?
(A)
500 m/s
(B)
707 m/s
(C)
1000 m/s
(D)
2000 m/s
Q2
Container geometry: A closed cubic vessel filled with an ideal gas of density $\rho = 1.2\text{ kg/m}^3$. The rms velocity of the gas molecules is measured as $v_{rms} = 500m/s$.What is the pressure exerted by the gas molecules on the container walls?
Container geometry: A closed cubic vessel filled with an ideal gas of density $\rho = 1.2\text{ kg/m}^3$. The rms velocity of the gas molecules is measured as $v_{rms} = 500m/s$.
What is the pressure exerted by the gas molecules on the container walls?
(A)
$0.5 \times 10^5\text{ Pa}$
(B)
$1.0 \times 10^5\text{ Pa}$
(C)
$1.5 \times 10^5\text{ Pa}$
(D)
$3.0 \times 10^5\text{ Pa}$
Q3
A rigid cylinder contains 2 moles of Hydrogen gas ($H_2$) at temperature $T$. At this moderate temperature, vibrational modes are inactive, so each molecule possesses 5 active degrees of freedom.What is the total internal energy ($U$) of the gas sample?
A rigid cylinder contains 2 moles of Hydrogen gas ($H_2$) at temperature $T$. At this moderate temperature, vibrational modes are inactive, so each molecule possesses 5 active degrees of freedom.
What is the total internal energy ($U$) of the gas sample?
(A)
$3 RT$
(B)
$5 RT$
(C)
$6 RT$
(D)
$7 RT$
Q4
The mean free path of gas molecules in a chamber is $\lambda$. Due to chemical modification, the effective molecular diameter $d$ is doubled while keeping the number density $n$ of the molecules constant.What is the new mean free path $\lambda'$ of the gas?
The mean free path of gas molecules in a chamber is $\lambda$. Due to chemical modification, the effective molecular diameter $d$ is doubled while keeping the number density $n$ of the molecules constant.
What is the new mean free path $\lambda'$ of the gas?
(A)
Doubled
(B)
Halved
(C)
Reduced to one-fourth
(D)
Quadrupled
Q5
Gas Sample Gas Species Temperature ($K$) Molar Mass ($g/mol$) Sample A Helium (He) 300 4 Sample B Neon (Ne) 300 20 Sample C Argon (Ar) 300 40
Based on the table above, which gas sample has the highest average translational kinetic energy per molecule?
| Gas Sample | Gas Species | Temperature ($K$) | Molar Mass ($g/mol$) |
|---|---|---|---|
| Sample A | Helium (He) | 300 | 4 |
| Sample B | Neon (Ne) | 300 | 20 |
| Sample C | Argon (Ar) | 300 | 40 |
Based on the table above, which gas sample has the highest average translational kinetic energy per molecule?
(A)
Sample A
(B)
Sample B
(C)
Sample C
(D)
All three samples have equal average translational kinetic energy
Q6
Maxwell-Boltzmann velocity distribution curve: A plot showing three characteristic speeds on the horizontal axis ordered left-to-right as $v_1 < v_2 < v_3$.Which set correctly identifies $v_1, v_2,$ and $v_3$?
Maxwell-Boltzmann velocity distribution curve: A plot showing three characteristic speeds on the horizontal axis ordered left-to-right as $v_1 < v_2 < v_3$.
Which set correctly identifies $v_1, v_2,$ and $v_3$?
(A)
$v_1 = v_{mp},\; v_2 = v_{avg},\; v_3 = v_{rms}$
(B)
$v_1 = v_{rms},\; v_2 = v_{avg},\; v_3 = v_{mp}$
(C)
$v_1 = v_{avg},\; v_2 = v_{mp},\; v_3 = v_{rms}$
(D)
$v_1 = v_{mp},\; v_2 = v_{rms},\; v_3 = v_{avg}$
Q7
What is the theoretical ratio of most probable speed ($v_{mp}$), average speed ($v_{avg}$), and root-mean-square speed ($v_{rms}$) for an ideal gas?
What is the theoretical ratio of most probable speed ($v_{mp}$), average speed ($v_{avg}$), and root-mean-square speed ($v_{rms}$) for an ideal gas?
(A)
$1 : 1.128 : 1.225$
(B)
$1.225 : 1.128 : 1$
(C)
$1 : 1.225 : 1.128$
(D)
$1.128 : 1 : 1.225$
Q8
A thermal vessel contains a gas mixture of 1 mole of Helium (monoatomic, $f=3$) and 3 moles of Oxygen (diatomic rigid, $f=5$) in thermal equilibrium at temperature $T$.What is the total internal energy of this gas mixture?
A thermal vessel contains a gas mixture of 1 mole of Helium (monoatomic, $f=3$) and 3 moles of Oxygen (diatomic rigid, $f=5$) in thermal equilibrium at temperature $T$.
What is the total internal energy of this gas mixture?
(A)
$6 RT$
(B)
$7.5 RT$
(C)
$9 RT$
(D)
$10.5 RT$
Q9
An ideal gas is sealed in a container of fixed volume $V$. The absolute temperature of the gas is increased from $T$ to $3T$.By what factor does the rms speed of the gas molecules increase?
An ideal gas is sealed in a container of fixed volume $V$. The absolute temperature of the gas is increased from $T$ to $3T$.
By what factor does the rms speed of the gas molecules increase?
(A)
Triples
(B)
Increases by a factor of $\sqrt{3}$
(C)
Increases by a factor of 1.5
(D)
Remains unchanged
Q10
Statement I: The mean free path of gas molecules is inversely proportional to the mass density of the gas.
Statement II: At constant temperature, increasing the pressure of an ideal gas increases its mean free path.Which of the following statements is correct?
Statement I: The mean free path of gas molecules is inversely proportional to the mass density of the gas.
Statement II: At constant temperature, increasing the pressure of an ideal gas increases its mean free path.
Statement II: At constant temperature, increasing the pressure of an ideal gas increases its mean free path.
Which of the following statements is correct?
(A)
Both Statement I and Statement II are true
(B)
Both Statement I and Statement II are false
(C)
Statement I is true, but Statement II is false
(D)
Statement I is false, but Statement II is true
Q11
What is the total translational kinetic energy of 1 mole of a monoatomic ideal gas at $T = 300\text{ K}$? (Take $R = 8.314\text{ J/(mol}\cdot\text{K)}$)
What is the total translational kinetic energy of 1 mole of a monoatomic ideal gas at $T = 300\text{ K}$? (Take $R = 8.314\text{ J/(mol}\cdot\text{K)}$)
(A)
1.25 kJ
(B)
2.49 kJ
(C)
3.74 kJ
(D)
4.98 kJ
Q12
In the real gas van der Waals equation $\left(P + \frac{a}{V^2}\right)(V - b) = RT$, what physical correction does constant $a$ account for?
In the real gas van der Waals equation $\left(P + \frac{a}{V^2}\right)(V - b) = RT$, what physical correction does constant $a$ account for?
(A)
The finite volume occupied by gas molecules
(B)
The intermolecular attractive forces
(C)
The average translational velocity
(D)
The collision frequency with container walls
Q13
An air bubble of initial volume $V_0$ forms at the bottom of a lake where absolute temperature is $T_0$. The bubble rises to the surface where the absolute temperature is $2T_0$ and the pressure is half of the pressure at the bottom.What is the final volume of the air bubble when it reaches the surface?
An air bubble of initial volume $V_0$ forms at the bottom of a lake where absolute temperature is $T_0$. The bubble rises to the surface where the absolute temperature is $2T_0$ and the pressure is half of the pressure at the bottom.
What is the final volume of the air bubble when it reaches the surface?
(A)
$V_0$
(B)
$2 V_0$
(C)
$4 V_0$
(D)
$8 V_0$
Q14
Gas Type Degrees of Freedom ($f$) Ratio $\gamma = C_p/C_v$ Monoatomic 3 1.67 Diatomic (rigid) 5 1.40 Triatomic non-linear (rigid) 6 $\gamma_x$
What is the theoretical value of $\gamma_x$ for a non-linear rigid triatomic gas molecule?
| Gas Type | Degrees of Freedom ($f$) | Ratio $\gamma = C_p/C_v$ |
|---|---|---|
| Monoatomic | 3 | 1.67 |
| Diatomic (rigid) | 5 | 1.40 |
| Triatomic non-linear (rigid) | 6 | $\gamma_x$ |
What is the theoretical value of $\gamma_x$ for a non-linear rigid triatomic gas molecule?
(A)
1.67
(B)
1.40
(C)
1.33
(D)
1.25
Q15
At what temperature (in Kelvin) is the rms speed of Oxygen molecules ($O_2$, molar mass 32 g/mol) equal to the rms speed of Helium atoms (He, molar mass 4 g/mol) at 300 K?
At what temperature (in Kelvin) is the rms speed of Oxygen molecules ($O_2$, molar mass 32 g/mol) equal to the rms speed of Helium atoms (He, molar mass 4 g/mol) at 300 K?
(A)
600 K
(B)
1200 K
(C)
1800 K
(D)
2400 K
Q16
A rigid closed steel tank of constant volume contains an ideal gas at $27^\circ\text{C}$ (300 K) and initial pressure $P_0$. The tank is heated until its temperature reaches $327^\circ\text{C}$ (600 K).What is the final pressure of the gas in terms of initial pressure $P_0$?
A rigid closed steel tank of constant volume contains an ideal gas at $27^\circ\text{C}$ (300 K) and initial pressure $P_0$. The tank is heated until its temperature reaches $327^\circ\text{C}$ (600 K).
What is the final pressure of the gas in terms of initial pressure $P_0$?
(A)
$1.5 P_0$
(B)
$2.0 P_0$
(C)
$3.0 P_0$
(D)
$4.0 P_0$
Q17
What is the molar heat capacity at constant volume ($C_v$) for a rigid diatomic gas molecule with 5 degrees of freedom?
What is the molar heat capacity at constant volume ($C_v$) for a rigid diatomic gas molecule with 5 degrees of freedom?
(A)
$\frac{3}{2} R$
(B)
$\frac{5}{2} R$
(C)
$\frac{7}{2} R$
(D)
$3 R$
Q18
Gas molecules in a chamber have a mean free path $\lambda = 2.0 \times 10^{-7}m$ and an average speed $v_{avg} = 500m/s$.What is the collision frequency ($f_{coll}$) of a molecule in this chamber?
Gas molecules in a chamber have a mean free path $\lambda = 2.0 \times 10^{-7}m$ and an average speed $v_{avg} = 500m/s$.
What is the collision frequency ($f_{coll}$) of a molecule in this chamber?
(A)
$1.0 \times 10^8\text{ s}^{-1}$
(B)
$2.5 \times 10^8\text{ s}^{-1}$
(C)
$2.5 \times 10^9\text{ s}^{-1}$
(D)
$5.0 \times 10^9\text{ s}^{-1}$
Q19
Statement I: According to the law of equipartition of energy, each quadratic degree of freedom contributes $\frac{1}{2} k_B T$ to the average energy of a particle.
Statement II: A solid containing $N_A$ atoms oscillating in 3 dimensions has 6 degrees of freedom per atom, leading to a molar specific heat capacity of $3R$.Which of the following statements is correct?
Statement I: According to the law of equipartition of energy, each quadratic degree of freedom contributes $\frac{1}{2} k_B T$ to the average energy of a particle.
Statement II: A solid containing $N_A$ atoms oscillating in 3 dimensions has 6 degrees of freedom per atom, leading to a molar specific heat capacity of $3R$.
Statement II: A solid containing $N_A$ atoms oscillating in 3 dimensions has 6 degrees of freedom per atom, leading to a molar specific heat capacity of $3R$.
Which of the following statements is correct?
(A)
Both Statement I and Statement II are true
(B)
Both Statement I and Statement II are false
(C)
Statement I is true, but Statement II is false
(D)
Statement I is false, but Statement II is true
Q20
A container holds a mixture of 2 moles of Helium ($C_{v1} = 1.5 R$) and 3 moles of Nitrogen ($C_{v2} = 2.5 R$).What is the effective molar heat capacity at constant volume ($C_{v,\text{mix}}$) of this mixture?
A container holds a mixture of 2 moles of Helium ($C_{v1} = 1.5 R$) and 3 moles of Nitrogen ($C_{v2} = 2.5 R$).
What is the effective molar heat capacity at constant volume ($C_{v,\text{mix}}$) of this mixture?
(A)
$1.8 R$
(B)
$2.0 R$
(C)
$2.1 R$
(D)
$2.3 R$

Discussion 0
Enjoyed this content?
Share your rating and feedback with us. It takes less than a minute!