JEE · Physics · Kinetic Theory of Gases doubts
9 doubts found
Hydrogen and oxygen are at the same temperature. Which molecules move faster, and does that mean they have more kinetic energy?
At the same absolute temperature both gases have the same average translational kinetic energy per molecule, 3k_BT/2.
Why is gamma usually larger for a monatomic gas than for a diatomic gas?
Adding heat to a monatomic gas mainly feeds three translational modes, so f = 3 and gamma = 5/3.
What does “Microscopic origin of gas pressure” actually mean in Kinetic Theory of Gases, and why does it matter for JEE?
Gas pressure comes from molecular collisions with container walls. Each collision changes molecular momentum; the wall experiences the equal and opposite momentum transfer spread over time and area.
I keep getting “Microscopic origin of gas pressure” questions wrong in Kinetic Theory of Gases. What's the trap?
imagining pressure as a stored substance inside the gas.
What does “Temperature and molecular kinetic energy” actually mean in Kinetic Theory of Gases, and why does it matter for JEE?
For an ideal gas, absolute temperature measures average translational kinetic energy per molecule: 3k_BT/2. At the same temperature, light and heavy molecules have the same average translational energy but different rms speeds.
I keep getting “Temperature and molecular kinetic energy” questions wrong in Kinetic Theory of Gases. What's the trap?
saying every molecule has the same speed at a given temperature.
What does “Root-mean-square speed” actually mean in Kinetic Theory of Gases, and why does it matter for JEE?
The rms speed is the square root of the mean of v^2, not the ordinary mean speed. It links the molecular picture to measurable pressure and temperature.
I keep getting “Root-mean-square speed” questions wrong in Kinetic Theory of Gases. What's the trap?
using Celsius temperature in the rms-speed formula.
What does “Degrees of freedom” actually mean in Kinetic Theory of Gases, and why does it matter for JEE?
A degree of freedom is an independent quadratic way a molecule can store energy. Translational, rotational and vibrational modes contribute depending on molecular structure and temperature.