Describes the spread of molecular speeds in a gas, broadening and shifting with temperature.
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The Maxwell-Boltzmann distribution describes how the speeds of molecules in an ideal gas are spread over a range. The curve starts at zero, rises to a peak at the most probable speed, and then falls off with a long tail of fast molecules, so it is skewed to the right. Raising the temperature shifts the peak to higher speeds and broadens the curve, while the total area under the curve stays constant because the number of molecules does not change. Lighter molecules have a distribution that extends to higher speeds at the same temperature. The distribution explains why reactions speed up with temperature, since more molecules have enough energy to overcome an energy barrier.
Key ideas: Three characteristic speeds sit on the curve: most probable below mean below rms. Doubling the temperature moves the peak right and lowers its height, but the area stays one. The fraction of molecules above an energy Ea scales roughly as exp(-Ea/RT), which is why a 10 degree rise can double a rate.
Common mistakes and connections: Students think raising temperature speeds up all molecules equally, or that the curve ends at a maximum speed. The tail extends indefinitely. Another error is reading the peak height as the number of molecules at the highest speed. Connects to Arrhenius kinetics, evaporation of fast molecules, and catalysts, which change the barrier but not the distribution.
Molecular speeds spread over a skewed curve; raising temperature shifts the peak to higher speed and broadens it, with a long fast tail. The interactive lesson shows this as a live animation or chart.
At a higher temperature a larger fraction of molecules has enough kinetic energy to overcome an activation barrier, so the reaction rate increases.
Describes the spread of molecular speeds in a gas, broadening and shifting with temperature.
Maxwell-Boltzmann Distribution is a intermediate topic in States of Matter & Solutions. It builds on the vocabulary of beginner topics in this area.
Study these earlier topics in States of Matter & Solutions first: Diffusion, Effusion, Root Mean Square Speed.
The next topics in States of Matter & Solutions are Average Kinetic Energy of Gas and Molar Volume.
Yes. The interactive lesson includes a self-check question on Maxwell-Boltzmann Distribution, and the States of Matter & Solutions quiz draws on every topic in this area.
Maxwell-Boltzmann Distribution is topic 23 of 109 in States of Matter & Solutions.