Maxwell-Boltzmann distribution

The Maxwell–Boltzmann distribution curve is shown for a gaseous reaction mixture.

What is represented by the total area under the curve?

This question is about ethanoic anhydride.

In the gas phase, ethanoic anhydride (CH₃CO)₂O decomposes to form ethenone.

The equation is

Ethenone is the simplest member of the ketene homologous series. Ketenes all contain one C=C double bond and one C=O double bond.

Deduce the general formula for the ketene homologous series.

Figure 11 shows an incomplete suggested mechanism for the decomposition of ethanoic anhydride.

Complete the mechanism in Figure 11 by adding three curly arrows and any relevant lone pairs of electrons.

For a chemical reaction the relationship between the rate constant, k, and the temperature, T, is shown by the Arrhenius equation.

For the decomposition of gaseous ethanoic anhydride

the activation energy, E_a = 34.5 kJ mol^–1

At temperature T₁ the rate constant, k = 2.48 10⁸ s^–1

The gas constant, R = 8.31 J K^–1 mol^–1

Sketch the Maxwell–Boltzmann distribution of molecular energies for gaseous ethanoic anhydride at temperature T₁ and at a higher temperature T₂

Include a label for each axis, and mark on the appropriate axis a typical position for the activation energy.

Explain why the rate of reaction is faster at T₂

Explanation

This is a Maxwell–Boltzmann distribution for a gaseous reactant.

What is represented by the total area under the curve?

Consider the change that occurs in the shape of the curve for the distribution of molecular energies in a gas when the temperature of the gas is increased.

Which is a correct statement about the gas molecules at a higher temperature?

Which statement about the distribution curve of molecular energies in an ideal gas at a given temperature is correct?