An ideal gas is confined in a closed container and slowly heated. As the temperature rises, which of the following statements are correct?
(A) | The mean free path of gas molecules decreases. |
(B) | The mean collision time between the molecules decreases. |
(C) | The mean free path remains unchanged. |
(D) | The mean collision time remains unchanged. |
1. | (C) and (D) only |
2. | (A) and (B) only |
3. | (A) and (D) only |
4. | (B) and (C) only |
Consider a gas of triatomic molecules. The molecules are assumed to be triangular, composed of massless rigid rods with atoms at the vertices. \(T\) is:
The internal energy of a mole of the gas at temperature
1. | \( 3 R T \) | 2. | \(\dfrac{5}{2} R T \) |
3. | \( \dfrac{9}{2} R T \) | 4. | \( \dfrac{3}{2} R T \) |
Match the \(C_p/C_V\) ratio for ideal gases with different type of molecules :
Column I | Column II | ||
(A) | Monatomic | (I) | \(7/5\) |
(B) | Diatomic rigid molecules | (II) | \(9/7\) |
(C) | Diatomic non-rigid molecules | (III) | \(4/3\) |
(D) | Triatomic rigid molecules | (IV) | \(5/3\) |
1. | (A)-(III), (B)-(IV), (C)-(II), (D)-(I) |
2. | (A)-(II), (B)-(III), (C)-( I), (D)-(IV) |
3. | (A)-(IV), (B)-(II), (C)-(I), (D)-(III) |
4. | (A)-(IV), (B)-(I), (C)-(II), (D)-(III) |
The pressure of an ideal gas is written as \(p=\dfrac{2E}{3V},\) where \(E\) is the total kinetic energy, and \(V\) is the volume.
This statement is:
1. | always true. |
2. | true for mono-atomic gases. |
3. | always false. |
4. | true for diatomic gases. |
1. | \(T_\mathrm {H_{2}}=T_\mathrm{H e}\) | 2. | \(\dfrac{T_\mathrm{H_2}}{2}=\dfrac{T_\mathrm{He}}{4}\) |
3. | \(5 T_\mathrm{H_2}=3 T_\mathrm{He}\) | 4. | \(\dfrac{T_\mathrm{H_{2}}}{5}=\dfrac{T_\mathrm{{He }}}{3}\) |
1. | \(p_1 > p_2\) |
2. | \(p_2 > p_1\) |
3. | \(p_1 = p_2\) |
4. | \(p_1\) and \(p_2\) depends on pressure. | the relationship between
Assertion (A): | The translational kinetic energy of every molecule of an ideal gas increases by \(50\%,\) if the absolute temperature is raised by \(50\text{%}.\) |
Reason (R): | The average translational kinetic energy of the molecules of an ideal gas is directly proportional to its absolute temperature. |
1. | (A) is True but (R) is False. |
2. | (A) is False but (R) is True. |
3. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
4. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
1. | helium and hydrogen molecules have the same kinetic energy on average. |
2. | RMS speeds of helium and hydrogen molecules are equal. |
3. | the translational kinetic energy of hydrogen and helium molecules is equal. |
4. | all of the above are true. |
1. | increases. |
2. | decreases. |
3. | remains constant. |
4. | first increases, then decreases. |