The graph shows the distribution of kinetic energies for a reaction involving two gases - Scottish Highers Chemistry - Question 24 - 2019

To determine which graph represents the effect of increasing temperature on the distribution of kinetic energies for gas molecules, we need to understand how temperature affects molecular motion.

1. Understanding Temperature and Kinetic Energy: As temperature increases, the average kinetic energy of the molecules also increases. This means that a larger number of molecules will have higher kinetic energy at elevated temperatures.

2. Analyzing the Graphs:

   • Graph A: Shows a distribution where fewer molecules have higher energy compared to the original graph.
   • Graph B: Reflects a distribution that is somewhat similar to the original but does not properly illustrate an increase in higher kinetic energy.
   • Graph C: Displays a broader distribution, suggesting an increase in both the average kinetic energy and the number of molecules at higher energies.
   • Graph D: Also shows a significantly different shape with a larger number of molecules in lower energy regions, which does not represent an increase in temperature.

3. Conclusion: The correct representation of increased temperature would be Graph C, as it illustrates a shift in the energy distribution towards higher kinetic energies, in line with the principles of kinetic molecular theory.