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#	Question	Answer
1	What is kinetic theory of gases?	The theory that explains the behaviour of gases based on the idea that a gas consists of rapidly moving atoms or molecules.
2	What is the ideal gas equation?	\( PV = \mu RT \).
3	What is Boyle's law?	At constant temperature, the pressure of a given mass of gas is inversely proportional to its volume: \( PV = \text{constant} \).
4	What is the expression for the pressure of an ideal gas according to kinetic theory?	\( P = \frac{1}{3} n m \overline{v^2} \).
5	What is the average translational kinetic energy of a molecule?	\( \frac{3}{2} k_B T \).
6	How many translational degrees of freedom does a monatomic gas molecule have?	Three.
7	What is the molar specific heat at constant volume for a monatomic gas?	\( C_v = \frac{3}{2} R \).
8	What is the expression for mean free path?	\( l = \frac{1}{\sqrt{2} n \pi d^2} \).
9	What is the kinetic interpretation of temperature?	The average kinetic energy of a molecule is \( \frac{3}{2} k_B T \).
10	Three vessels contain neon, chlorine and uranium hexafluoride at the same temperature and pressure. In which case is \( v_{rms} \) the largest?	Neon.
11	A vessel contains neon and oxygen with partial pressures in the ratio 3:2 (Example 12.4). What is the ratio of the number of molecules of neon to oxygen?	3:2, since \(P_1/P_2=\mu_1/\mu_2=N_1/N_2\) at the same V and T.
12	A ball rebounding off a bat moving towards it speeds up (relative to the ground). How does this explain why a gas heats up when compressed by an inward-moving piston?	Each molecule striking the inward-moving piston rebounds faster, just like the ball off the moving bat — so the gas molecules' average speed (and hence temperature) increases. (Example 12.7)
13	Is the average of a squared quantity, \(\langle v^2 \rangle\), always equal to the square of the average, \((\langle v \rangle)^2\)?	No — these are generally different quantities; the average of a squared quantity is not necessarily the square of the average.
14	What does Gay Lussac's law state?	When gases combine chemically to yield another gas, their volumes are in the ratios of small integers.
15	For a vibrating diatomic gas, what are \(C_p\) and \(\gamma\)?	\( C_p = \dfrac{9}{2}R \), \( \gamma = \dfrac{9}{7} \).
16	In a PV/T vs P plot for a real gas at two temperatures (Exercise 12.3), what does the dotted line represent, and what is the value of PV/T where both curves meet the y-axis?	The dotted line represents ideal gas behaviour (PV/T independent of P). Both curves meet the y-axis (P→0) at the same value, \(\mu R\), since this depends only on the amount of gas, not its temperature or identity.
17	For the same nitrogen gas, how does the time between successive collisions compare to the duration of an individual collision (molecule size / speed)?	The time between collisions (≈\(2.2\times10^{-10}\) s) is about 500-550 times longer than the collision's own duration (≈\(4\times10^{-13}\) s) — confirming that molecules spend almost all their time moving freely, not colliding.
18	For a polyatomic gas with f vibrational modes, express f in terms of \(\gamma=C_p/C_v\).	\( f = \dfrac{4-3\gamma}{\gamma-1} \), rearranging \(\gamma=(4+f)/(3+f)\). (NEET 2024)
19	A gas has rms speed 200 m/s at 27°C (300 K). What is its rms speed at 127°C (400 K)?	\(400/\sqrt3\approx231\) m/s, from \(v_{rms}\propto\sqrt{T}\): \(v_2=200\sqrt{400/300}\) — independent of any pressure change. (NEET 2016)